The Seas Around Scotland - nature.scot Note...Nature and Natural Resources ... MCS Marine Conservation Society ... landscape and recreation are largely beyond the scope of our present

Working with Scotland’s people to care forour natural heritageScottish Natural Heritageis a government body responsible to the Scottish Executive and Scottish Parliament.

Our mission statement is:Working with Scotland’s people to care for our natural heritage.

Our aim is:Scotland’s natural heritage is a local, national and global asset. We promote itscare and improvement, responsible enjoyment, greater understanding andappreciation, and sustainable use now and for future generations.

Our operating principles are:We work in partnership, by co-operation, negotiation and consensus, wherepossible, with all relevant interests in Scotland: public, private and voluntaryorganisations, and individuals.

We operate in a devolved manner, delegating decision-making to the local levelwithin the organisation to encourage and assist SNH to be accessible, sensitiveand responsive to local needs and circumstances.

We operate in an open and accountable manner in all our activities.

Further informationfurther copies of this reportare available fromScottish Natural HeritagePublications SectionBattlebyRedgortonPerth PH1 3EWt: 01738 444177t: 01738 458613e: [email protected]: www.snh.org.uk/trends

ISBN 1 85397 4048

NPO.5K0804

PRICE £10

Natural Heritage TrendsThe Seas Around Scotland

2004

Working with Scotland’s people to care for our natural heritage

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Natural Heritage Trends

2004

Graham Saunders

Scottish Natural Heritage

Battleby, Perth

2004

The Seas Around Scotland

Acknowledgements

This report was supervised and edited by Ed Mackey andJohn Baxter.

Grateful thanks are due to Ed Mackey, Phil Shaw, CatrionaBurns, Beth Mouat, Katie Gillham, Sandy Downie and JohnBaxter for their major contributions to the text of thispublication.

Thanks also to Colin Galbraith and George Lees for furthereditorial comment and suggestions.

Thanks for contributions, use of data, thoughts and commentsshould also go to David Donnan, John Gordon, AntonEdwards, Judy Dobson, Bob Reid, Calum Duncan, the MarineConservation Society, the Sea Mammal Research Unit, theScottish Environment Protection Agency and the ScottishExecutive.

Finally, many thanks are due to Bill Forbes, Betty Commonand Jim Jeffrey for assisting in the design and production.

Front cover: Jewel anemones (Corynactis viridis), G. SaundersInserts: Andi Robertson/SNH, MCNR/SNH, G. Saunders/SNH.

Natural Heritage Trends: The Seas Around Scotland 2004 353

Contents

Acknowledgements 2Abbreviations 5Foreword 7Introduction 9

Part 1 11Knowledge of the marine environment 111 Knowledge and enjoyment 12

Introduction 12Trends 12Issues and implications 15Sources of data 16References 16

2 Marine conservation 17Introduction 17Trends 20Issues and implications 23Sources of data 25References 25

Part 2 27Marine life 273 Sharks, skates and rays 28


4 Dolphins, porpoises and whales 33Introduction 33Trends 33Issues and implications 36Sources of data 37References 38

5 Seals 39Introduction 39Trends 39Issues and implications 40Sources of data 41References 41

6 Seabirds 42Introduction 42Trends 42Issues and implications 46Sources of data 46References 46

Part 3 47The use of the sea 477 Mariculture 48


8 Continental shelf fisheries 52Introduction 52Trends 53Issues and implications 58Sources of data 63References 63

9 Deep-water fish and fisheries 65Introduction 65Trends 66Issues and implications 66Sources of data 68References 68

Part 4 69Quality of the marine environment 6910 Coastal and estuarine environment quality 70


11 Marine litter 78Introduction 78Trends 79Issues and implications 81Sources of data 83References 84

12 Non-native species 85Introduction 85Trends 85Issues and implications 88References 94

13 Environmental change 95Introduction 95Trends 95Issues and implications 98Sources of data 101References 101Additional source 101

4 Natural Heritage Trends: The Seas Around Scotland 2004 3535

Part 5 103Conclusions 10314 Conclusions 104

Summing up 110Reference 110

Part 6 111Appendices 111Appendix 1:

SEPA coastal waters classification scheme 112Appendix 2:

SEPA estuarine waters classification scheme 113Appendix 3:

definition of microbiological requirements for guideline and mandatory passes of bathing waters based on the minimum number of samples (20) that are taken from each location 114

Appendix 4:Scottish marine environment data sources 115Biological 116Biological and chemical 127Physical 135

Part 7 151Have Your Say! 151

What do you think of the report? 152Index 155


Abbreviations

ACFM Advisory Committee on FisheryManagement

ASCOBANS Agreement on Small Cetaceans of theBaltic and North Seas

ASP amnesic shellfish poisoningBGS British Geological SurveyBOD biological oxygen demandBODC British Oceanographic Data CentreCEFAS Centre for Environment, Fisheries and

Aquaculture ScienceCFP Common Fisheries PolicyCITES Convention on International Trade in

Endangered Species of Wild Fauna andFlora

CONSLEX Continental Slope ExperimentCPUE catch per unit effortcSAC candidate Special Area of ConservationCTD conductivity, temperature and depthDDT dichlorodiphenyltrichloroethaneDEFRA Department for Environment, Food and

Rural AffairsDML Dunstaffnage Marine LaboratoryDSP diarrhetic shellfish poisoningEC European CommissionEQS environmental quality standardsEU European UnionFAO Food and Agriculture Organisation of

the United NationsFRS Fisheries Research ServicesGIS geographical information systemsha hectareIACMST Inter-Agency Committee on Marine

Science and TechnologyICES International Council for the Exploration

of the SeaIOS Institute of Oceanographic Sciences ISA infectious salmon anaemiaIUCN International Union for Conservation of

Nature and Natural Resources (or WorldConservation Union)

IWC International Whaling CommissionJCD Joint Cetacean DatabaseJONSDAP Joint North Sea Data Acquisition ProjectJNCC Joint Nature Conservation CommitteeJRC James Rennell Centre for Ocean

Circulationm metreMAFF Ministry of Agriculture, Fisheries and

FoodMARPOL International Convention for the

Prevention of Pollution from Ships

MBA Marine Biological Association of theUnited Kingdom

MCS Marine Conservation SocietyMLURI Macaulay Land Use Research InstituteMNCR Marine Nature Conservation ReviewNANSEN North Atlantic Norwegian Sea

ExchangeNERC Natural Environment Research CouncilNERPB North East River Purification BoardNHM Natural History MuseumNORSWAM North Sea wave modelOSPAR Oslo and Paris Conventions for the

Prevention of Marine PollutionOWS ocean weather shipPCBs polychlorinated biphenylsPDV phocine distemper virusPML Plymouth Marine LaboratoryPOL Proudman Oceanographic LaboratoryPS particle size analysispSAC possible Special Area of ConservationPSP paralytic shellfish poisoningROSCOP Report of Observations/Samples

Collected by OceanographicProgrammes

RPB River Purification BoardSAC Special Area of ConservationSAHFOS Sir Alister Hardy Foundation for Ocean

ScienceSAMS Scottish Association for Marine ScienceSCOS Special Committee on SealsSEPA Scottish Environment Protection AgencySMRU Sea Mammal Research UnitSNH Scottish Natural HeritageSOAFD Scottish Office Agriculture and Fisheries

DepartmentSPA Special Protection AreaSRD sewage-related debrisSRPB Solway River Purification BoardSSSI Site of Special Scientific InterestSTD salinity, temperature, depthTBT tributyltinTERC Tay Estuary Research CentreTRPB Tay River Purification BoardUKCIP02 UK Climate Impacts Programme 2002UKOOA UK Offshore Operators AssociationUNESCO United Nations Education, Scientific and

Cultural OrganisationUOR undulating oceanographic recorderWFD Water Framework DirectiveWOCE World Ocean Circulation Experiment

6 Natural Heritage Trends: The Seas Around Scotland 2004


Foreword

In presenting this analysis of the seas around Scotland, three questions might come to mind: whyhave we done it?; how does it relate to our policies and plans?; and how can the outputs be used totake forward the work of Scottish Natural Heritage (SNH)? I shall address them in turn.

In our Natural Heritage Futures policy statement on Scotland’s coasts and seas, which we published in2002, we point out that comparatively little is known about the marine environment. Nevertheless, thewealth of information that does exist, from many and disparate sources, is not readily known oraccessible to the non-specialist. Our task has been, quite simply, to bring together the best informationavailable on natural heritage trends in the marine environment. Inevitably, we have had to put boundson this. Our focus here is on life within the seas. While no less relevant, matters relating to theland/sea margin, landscape and recreation are largely beyond the scope of our present study. Trendsacross recent decades have been documented up to the start of 2004.

The SNH Natural Heritage Futures programme sets out challenging, but achievable, natural heritageobjectives within a 25-year time horizon. Eight key objectives are defined for coasts and seas,including, for example, improving understanding of marine ecosystems; safeguarding and enhancingmaritime biodiversity; ensuring that fishing is sustainable; and improving the water quality of estuariesand seas. This report provides evidence to back up our policies, and we address that specifically in theconclusions. While this report is of value to SNH, it is for the widest possible readership.

In relation to the third of my questions, the information contained within this report is already beingput to use. We are working with the Scottish Executive and others on a Scottish Sustainable MarineEnvironment Initiative, on the preparation of a Marine Implementation Plan for the forthcomingScottish Biodiversity Strategy and on the specification of biodiversity indicators for Scotland.Summary trend notes are being made publicly accessible through the SNH web site.

Many hands have been involved in bringing this report into print, the latest in our Natural HeritageTrends series. We expect that natural heritage trends will appeal to a broad range of interests inScotland and beyond; within the public, private and voluntary sectors; for use in education; and toguide and evaluate policy and action. We welcome your thoughts and views, and have included afeedback form at the end of this report that can be copied and returned to us, or completedelectronically.

Let me close on a quote from the report itself: ‘Scotland’s seas, positioned between subpolar andsubtropical influences, are among the most biologically productive in the world. They support afascinating and diverse assemblage of marine habitats and species, provide a wealth of importantnatural resources, and offer abundant opportunities for enjoyment’. We have a magnificent marinenatural heritage. I hope you will continue to enjoy it, prosper from it and come to appreciate andrespect it more through this new account of the seas around Scotland.

John Markland

Chairman, Scottish Natural Heritage


high water springhigh tide

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Figure 1. Profile of Scottish seas.Illustration by Claire Hewitt

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Introduction

Scotland’s seas, positioned between subpolar and subtropical influences are among the mostbiologically productive in the world. They support a fascinating and diverse assemblage ofmarine habitats and species, provide a wealth of important natural resources and offer abundant

opportunities for enjoyment.

The sea surrounding Scotland is integral to its character, influencing the geography of the coastline bywave action and tidal flows, controlling climate with a complicated convergence of offshore watermasses and providing a rich medium in which a vast array of animal and plant forms, many ofinternational importance, flourish. The Scottish coastline is remarkably intricate and variable. To thewest, the Atlantic coast is characterised by a highly indented fjordic and fjardic landscape with exposedislands, high sea cliffs and rocky skerries. To the east, the North Sea coast is predominantly low lying,often supporting sedimentary shores with only intermittent stretches of cliff. This part of thecoastline is also less convoluted but is deeply penetrated by five large inlets or firths. The outer islesform three major archipelagos of Shetland, Orkney and the Western Isles, each with a range ofdistinctive coastal habitats.

Owing to the complexity of the boundary between the land and the sea, the length of the Scottishcoastline is difficult to determine, but it is often stated to be about 11,800 km, representing over 8%of the entire coastline of Europe (Doody, 1999). However, coastal length is scale-dependent.Advances in computer mapping technology have allowed improved estimates to be made. Calculationsbased on a 1:25,000 scale suggest a revised Scottish coastline length of some 16,491 km (MLURI,1993). Moreover, calculation of the area of sea enclosed within the 12-mile territorial limit returned afigure of 88,597 km2, suggesting that some 53% of Scotland’s administrative territory is essentiallymarine in nature (Scottish Office GIS Unit, personal communication).

Human influence on the marine environment is of growing concern throughout the world and,despite a relatively low population density, evidence of human impact is commonly observed aroundScotland’s coasts. Since the time of the earliest human settlers, the sea has been of supremeimportance: as a provider of food, as an effective means of transport, as an important resource forcommerce and as a receiver of domestic and industrial wastes.

This audit was undertaken with the purpose of bringing together the best information availablerelating to marine natural heritage trends. The report has been prepared to meet an identified need foran assessment of the state of Scotland’s marine environment in order to inform and guide policydevelopment and advice requirements. During the preparation of the report it was recognised that, inecological terms, international boundaries are largely meaningless when drawn across a continuousbody of water. Hence, in examining some of the problems associated with Scotland’s seas some ofthe information was necessarily drawn from sources with European or even wider perspectives.

It is envisaged that this account of the seas around Scotland and their wildlife will be of interest to awider audience, within government, in environmental organisations, in research and in education. Thegeographical focus is Scotland, but with an international readership in mind. Information has beenpresented with scientific rigour, but in ways that are hopefully interesting and understandable to anon-specialist readership.

Trend data are few and far between for the marine environment, and so this is necessarily anincomplete account. Nevertheless, the chapters of this report bring together a wealth of newinformation from a wide range of sources that would not otherwise be readily accessible. An examplefrom each chapter is as follows:


1 Spectacular recent discoveries include the submarine structures of St Kilda and coldwater coral.

2 Biodiversity Action Plans have been prepared for 13 marine habitats and 17 marine species, orgroups of species, occurring in Scottish waters.

3 The basking shark (Cetorhinus maximus), which is globally vulnerable and regarded ascommercially extinct in British territorial waters, has been protected by law under the Wildlifeand Countryside Act since 1998. Also vulnerable to commercial exploitation, the angel shark(Squatina squatina), common skate (Dipturus batis) and long-nosed skate (Dipturus oxyrhinchus) wererecommended for similar protection in 2002.

4 According to the OSPAR Commission (Oslo and Paris Conventions for the Prevention ofMarine Pollution), most species of large whale are showing signs of recovery in Europeanwaters.

5 Harbour seal numbers have rapidly returned to, or exceed, pre-1988 epidemic (phocinedistemper virus) levels; however, a new outbreak of PDV occurred in 2002.

6 Between 1969–1970 and 1985–1987, 11 out of 18 seabird species showed a marked increase intheir breeding populations (i.e. by at least 10%), and four showed a marked decline.

7 Commercial salmon farming began in Scotland in 1969. In 2002, over 145,000 tonnes of farmedAtlantic salmon (Salmo salar) was produced.

8 Of the 16 commercially exploited sea fish species for which Scottish data are available, sevenwere considered by the International Council for the Exploration of the Sea (ICES) to beoutside safe biological limits in 2002/03.

9 Among 12 commercially exploited deep-water species, five were considered by the ICES to beharvested outside safe biological limits in 2000 and the status of others is largely unknown.

10 Upper Clyde estuary sediments, dominated in the 1970s by a few pollution-tolerant species, nowhave a more diverse invertebrate community and rising numbers of fish species.

11 Seabirds and their chicks are susceptible to ingesting litter. Plastic bags can cause gut blockageand death by starvation among turtles, which mistake them for their jellyfish prey.

12 Of 24 non-native marine species found in Scottish waters, ten have potentially harmful effectson the environment and/or on commercial interests.

13 Perhaps in response to changing sea temperature, a shifting distribution of fish species is evidentin the northerly retreat of eelpout (Zoarces viviparus) and advance of fatherlasher (Myoxocephalus

scorpius) in the lower Forth estuary.

Technical terms are kept to a minimum and explained as fully as possible where they occur. Somecommonly encountered terms are illustrated in Figure 1.

References

Doody, J. P. (1999). The Scottish coast in a European perspective. In: Scotland's Living Coastline. Baxter,J. M., Duncan, K., Atkins S. and Lees, G. (eds), pp. 15–29.The Stationery Office, London.

Hiscock, K. Southward, A., Tittley, I., Adam, J. and Hawkins, S. (2001). The Impact of Climate Changeon Subtidal and Intertidal Benthic Species in Scotland. Report to Scottish Natural Heritage from theMarine Biological Association of the UK. Phase 1: Introduction and species researched. Research Surveyand Monitoring Report, No. 182. Scottish Natural Heritage, Edinburgh.

MLURI. (1993). The Land Cover of Scotland 1988. Final report. Macaulay Land Use Research Institute,Aberdeen.

Knowledge of the marine environmentPart 1


Knowledge and enjoyment1

Box 1.1 Tourism

The ruggedness and relatively unspoilt nature of the Scottishcoastline is a major tourist attraction that contributessignificantly to both national and local economies.Excursions to view wildlife in natural surroundings areincreasingly popular. Marine wildlife tourism in Scotlandgenerated revenues of some £57 million and providedaround 2,670 full-time jobs in 1996 (Masters, 1998).Whale-watching may account for up to 12% of local tourismrevenue (Hebridean Whale and Dolphin Trust, 2001).Education and raising public awareness can be addedbenefits.Nevertheless, wildlife tourism remains, for the most part,underdeveloped. A future programme of coordinated andsustainable tourism development, with due regard to thebalance between access and conservation, could provideimportant socio-economic benefits for coastal communities.This might, for example, be achieved by integrating astrategy for the development of marine wildlife tourism withthe management of Special Areas of Conservation (SAC)and Special Protected Areas (SPAs).

Introduction

Scotland’s territorial seas constitute an areagreater than that of the seas around the restof the UK. They are as visually spectacular

and varied as the Scottish terrestrial environment,and provide opportunities for the development oftourism (Box 1.1).

Mostly, however, the sea remains hidden fromsight and comparatively little-studied. Because ofthe cost and technical challenges of working inthe sea, knowledge of species, habitats andcommunities, particularly those found below thelow-tide line, is still at an early stage.

TrendsDavison (1996) and Davison and Baxter (1997)estimated the total number of Scottish marinespecies to be more than 40,000 (Table 1.1).Among these, there are thought to be of theorder of 800 benthic algae and about 4,500benthic faunal species (excluding viruses andprotozoans).

Scottish marine survey work, as in the rest of theUK, has not been uniformly distributed, oftenbeing concentrated around favoured sites or closeto research or educational establishments. Amajor expansion of survey activity occurred inthe late 1970s and early 1980s (Figure 1.1) andwas further accelerated by the Marine NatureConservation Review (MNCR) in 1987. Theincreased survey effort was sustained into the1990s, partly because of the additionalinformation required to support the

Previous page: SNHSurveyor, Shetland.G.Saunders

Children playing atrockpool.L. Gill/SNH

Seal watching on the west coast.L. Gill/SNH


PhylumProtista = ProtozoaMesozoaPoriferaCnidaria

CtenophoresPlatyhelminthes

NemerteaRotiferaGastrotrichaKinorhynchaNematodaAcanthocephalaPriapulidaEntoproctaChaetognathaPogonophoraSipunculaEchiuraAnnelida

ChelicerataCrustacea

UniramiaTradigradiaMollusca

BrachiopodaBryozoaPhoronidaEchinodermata

Hemichordata

Tunicata*PiscesReptiliaMammaliaArchaebacteria and otherEubacteriaCyanobacteria = CyanophytaRhodophytaHeterokontophyta

Haptophyta =PrymnesiophytaCryptophytaDinophytaEuglenophytaChlophytaNon-lichenous fungiViruses

Grand total

Common name

Microscopic parasitesSpongesJellyfish, hydroids, anemones,coralsComb jelliesFlatworms and meiofaunalwormsRibbon worm‘Wheel animalcules’Meiofaunal roundwormsMicroscopic wormsRound wormsSpiny-headed wormsWorm-like animalsSimilar to sea matsArrow worms‘Beard’ wormsWorm-like animals‘Spoon’ wormsBristle and sludge worms,leachesSea spiders and marine mitesBranchiopods, barnacles,copepods, ostracods,stomatopods, shrimps, crabs,lobsters, etc.Marine arthropods‘Water bears’Chitons, limpets, sea snails,sea slugs, tusk shells, bivalvesoctopus, etc.Lamp shellsSea matsTube wormsFeather stars, sea stars,brittlestars, sea urchins, seacucumbers, etc.Acorn worms and planktoniclarvaeSea squirts and salpsFishSea turtlesSea mammalsBacteria

Blue–green algaeRed algaeGolden etc. algae, diatoms,phytoflagellatesPhytoflagellates

PhytoflagellatesDinoflagellatesEuglenoidsGreen algaeNon-lichenous fungiViruses

Excluding Protista = ProtozoaIncluding Protista = Protozoa

Great Britain and Ireland25,000–30,0002353 (360)375 (390)

3355–375 (377)

67 (85)10–1585 (140)15 (16)408 (410)10–20135 (45)222 (10)12 (21)7940 (995)

912,465 (2,665)

3–4161,395 (1,465)

18270 (290)3 (5)145

12+ (?)

120 (125)300 (332)528 (35)1,500–2,000

41 (120)350 (450)1,241 (1,341)+?

117

78440 (460)5–10160 (220)120 (150)2,000–2,500

13,625–14,666 (15,573)38,625–44,666 (45,573)

Scotland25,000–30,000Unknown250–300250–350

3300–350

60–7010–1580–906–10350–40010–20135–40202–1012–153800–900

60–702,000–2,460

3–416650–700

11120–1502100–130

11+ (?)

100250428–351,500–2,000

41 (70)2501,201–1,321+?

115

78250–4505–10100–150120–1502,000–2,500

11,207–13,605 (13,634)36,207–43,605 (43,634)

Table 1.1 The number of marine species occurring in Scottish waters (source: Davison, 1996; Davison and Baxter, 1997)

*Subphylum. Numbers in brackets indicate a ‘potential maximum’, i.e. numbers of those thatcould potentially occur plus those that have been recorded from British waters.


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Figure 1.3 Location of Scottish survey stations held in the MNCR database. Source: MNCR database

Figure 1.1Cumulative Scottish marine survey effort represented by entries into the MNCR database. (a) Surveys. (b) Individual survey stations.Source: MNCR database

Figure 1.2 Cumulative offshore oil and gas industry survey effort. (a) Surveys. (b) Individual survey stations.Source: UKbenthos database

Figure 1.4 Location of oil and gas industry survey stations. Source: UKbenthos database


implementation of the European Union (EU)Habitats Directive in the UK. Moreover, the early1980s was a time of increased oil and gasindustry activity, with environmental monitoringand sampling, largely of sediments,accompanying all major exploratory anddevelopment projects (Figure 1.2). Knowledge ofthe extent and distribution of marine habitats andspecies comes from a large number of sources.Even so, the coverage is widely dispersed andpatchy, with substantial sections of the north andeast coast remaining poorly surveyed (Figure 1.3),reflecting either operational considerations orselection of what might be considered‘interesting’ areas of coastline.

Scotland’s eastern and north-eastern shoresdefine the north-western boundary of the NorthSea, one of the most biologically productive areasin the world, and probably among the mostexploited. Offshore areas have undergoneintensive extraction of oil and gas, an industrythat has dominated the economy of the NorthSea basin for almost three decades. Oil industrysurvey effort has been mainly concentrated in theNorth Sea (Figure 1.4).

Issues and implicationsThe collation of these data, however incomplete,has revealed a rich and spectacular assemblage ofmarine communities and habitats. Survey recordsfrom the MNCR exist for almost 2,300 plant,invertebrate and fish species in Scottish waters.Many are common and widely distributed. Othersare clearly restricted in their distribution becauseof their dependence on particular conditions,such as those provided by the sheltered west-coast sea lochs.

Incomplete as the knowledge base is, newtechnology is making it possible to explore themarine environment more fully. Spectacularrecent discoveries have included cold-water corals(Box 1.2) and near-pristine conditions among thesubmarine structures of St Kilda (see Box 2.2).

Such information is invaluable in theestablishment of baselines against whichassessments of change, disturbance and theeffectiveness of marine environment protectionmay be achieved.

Box 1.2 Cold-water coral

Reef structures dominated byLophelia pertusa and incorporating anumber of other coral species havebeen discovered in the Norwegianwaters of the north-eastern NorthSea. They support a rich associatedfauna, with over 850 species livingon or within the reefs, and providean especially rich habitat for targetand non-target fish species. Vesselsin pursuit of high fish densities onthese reefs have caused damage, butin Norway many of the known reefsare now protected from furtherfishing-related damage.A survey in 2003 investigatedhistorical records of Lophelia pertusain Scottish waters, in particular to theeast of Mingulay, off Rum, and to thenorth-west of Skye. Results will helpto inform conservation measureswhich may be required to protectreef structures around Scotland.

Cold-water coral (Lophelia pertusa).B.Bett/Southampton Oceanographic Centre


Sources of dataThe MNCR database is the primary repository ofmarine survey data collected by all of the UKconservation agencies. It does, however, alsocontain data from a range of other sources. TheMNCR database is currently in the process ofbeing transferred to a new software platform.The new format will be referred to as MarineRecorder. The MNCR also maintains Mermaid, aweb-based version with reduced searchcapabilities.

The UKbenthos database contains all of thebiological and chemical information obtainedduring oil and gas industry surveys and wascompiled and made available to the public in2000 by the UK Offshore Operators Association(UKOOA).

ReferencesDavison, A. and Baxter, J. M. (1997). The numberof marine species that occur in Scottish coastalwaters. In: Biodiversity in Scotland: Status, Trendsand Initiatives. Fleming, L. V., Newton, A. C.,Vickery, J. A. and Usher, M. B. (eds), pp. 57–62.The Stationery Office, Edinburgh.

Davison, D. M. (1996). An Estimation of the TotalNumber of Marine Species that occur in ScottishCoastal Waters. Scottish Natural Heritage ReviewReport, No. 63. Scottish Natural Heritage,Edinburgh.

Hebridean Whale and Dolphin Trust. (2001).Whale-watching in West Scotland. Report for theDepartment for Environment, Food and RuralAffairs. Department for Environment, Food andRural Affairs, London.

Masters, D. (1998). Marine Wildlife Tourism:Developing a Quality Approach in the Highlandsand Islands. Unpublished report. Tourism andEnvironment Initiative and Scottish NaturalHeritage.


Marine conservation2

IntroductionThe conservation of Scotland’s coasts and seas isconsidered by many to be of the highest priority,and a wide range of campaigns, managementinitiatives and conservation designations arecurrently being employed to this end. A pivotalpoint in the creation of a framework for statutorynature conservation in Britain was reached withthe establishment of the first Sites of Special

Scientific Interest (SSSI) under the National Parksand Access to the Countryside Act 1949. Theapplication of this Act has facilitated thedevelopment of a network of scientificallyevaluated sites which are notable for the quality,extent and/or rarity of the species, habitats orgeological formations found within them.

Sites of Special Scientific Interest havesubsequently been identified under the Wildlifeand Countryside Act 1981, which created arequirement for the owner or occupiers to beinvolved directly in the notification process. InScotland, it is incumbent on Scottish NaturalHeritage (SNH) to identify activities that maydamage or destroy the feature of interest. Ownerand occupiers must then consult SNH prior tocarrying out such operations.

Since their inception, SSSI have excluded the areabelow the mean low-water spring tide, thusplacing a key component of Scotland’s maritimenatural heritage outside conservationmanagement legislation. Although provision forthe establishment of statutory Marine NatureReserves, comprising both littoral and sublittoralelements, was included in the 1981 Wildlife andCountryside Act, only a small number – alloutside Scotland – have been established so far.

In 1992, the European Community formallyadopted the Habitats Directive (Box 2.1) with theaim of establishing a Europe-wide network ofhigh-quality conservation sites, termed SpecialAreas of Conservation (SAC). Thesecomplement Special Protection Areas (SPAs),created under the Birds Directive (CouncilDirective 79/409/EEC). The introduction ofSAC has resulted in statutory site-basedconservation extending across both the littoraland sublittoral for the first time in Scotland.

Underwater rock wall,St Abbs.G. Saunders


FULL PAGE MAP

Figure 2.1 Scotland’s Special Areas of Conservation, January 2004. pSAC indicatespossible SAC, other sites are candidate SACs. Produced by Scottish Natural HeritageGeographic Information Group based on the Ordinance Survey 1:25,000 map. © ScottishNatural Heritage. Licence Number GD315 G0005. © Crown Copyright.


In May 1992, the member states of the EuropeanUnion adopted Council Directive 92/43/EEC onthe conservation of natural habitats and of wildfauna and flora, also known as the HabitatsDirective. The aim of the Directive is to conservebiodiversity throughout the European Union. Aprominent component of this is the establishment ofa pan-European protected areas network, knownas Special Areas of Conservation. As at 31 March2003, a total of 230 sites in Scotland, covering anarea of 874,808 ha, had been submitted by theUK government to the European Commission ascandidate Special Areas of Conservation (cSAC).Of these, 24 were put forward on the basis of theirEuropean importance for marine features, and afurther nine for their mix of marine and non-marineelements (SNH, 2003). The locations of sites areshown in Figure 2.1.

The requirements of the Habitats Directive weretransposed into UK legislation through theConservation (Natural Habitats etc.) Regulations1994. In the marine environment they apply towaters only within the 12 nautical mile (nm) limit ofterritorial seas. However, the subsequent OffshoreMarine Conservation (Natural Habitats, etc.)Regulations 2003 apply the Habitats Directive towaters of the UK continental shelf and as far as the200-nm limit over which the UK exercisessovereignty (DEFRA, 2003).

The UK government is currently consideringdesignating an area known as the Darwin Mounds,covering approximately 10,000 ha, as the firstoffshore cSAC. The Darwin Mounds are a uniquecollection of sand and coldwater coral moundslocated in the Rockall Trough at a depth of around1,000 m, some 185 km north-west of Shetland.Marine elements of cSAC currently extend to anarea of around 35,000 ha, equivalent to about0.4% of the sea area within the 12-nm limit.

Box 2.1 The Habitats Directive(sources:http://europa.eu.int/comm/environment/nature/habdir.htm; http://www.jncc.gov.uk/marine/offnat/sac_offshore_waters.htm; http://www.marlin.ac.uk/glossaries/legislation.htm)

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Figure 2.2Scotland’s Sites of Special Scientific

Interest with a coastal element. (a) Cumulative number of SSSI.

(b) Cumulative SSSI area.

Top: Lochs Duich, Long and Alsh cSAC.J.Baxter

Centre: Faray & Holm of Faray cSAC.J.Baxter

Left: Papa Stour cSAC.J.Baxter


TrendsThe significance of the maritime natural heritagewas reflected in the selection early on of anumber of coastal SSSI. Since 1949, the numberof Scottish SSSI with a coastal element hasincreased steadily, reaching 430 in 2003 (Figure2.2a). The area covered by these sites increasedrather less steadily (Figure 2.2b), with a tendency,after around 1975, towards the confinement of

coastal SSSI boundaries to smaller areas. By2003, SSSI with a coastal element coveredsome 327,504 ha of coastal land, althoughsome sites included only a small length ofshoreline.

The Habitats Directive requires sites to bedesignated SACs if they support typical, rare orvulnerable natural habitats and species of

Table 2.1Habitats Directive Annex 1 marine and coastal habitat types

Habitat

MarineEstuariesLarge shallow inlets and baysLagoonsMudflats and sandflats not covered by seawater at low tideReefsSand banks which are slightly covered by seawater at all timesPosidonia beds Submerged or partly submerged sea cavesMarine ‘columns’ in shallow water made by leaking gases

CoastalAtlantic salt meadows (Glauco–Puccinellietalia)Decalcified fixed dunes with Empetrum nigrumCoastal dunes with Juniperus spp. Dunes with Salix repens subsp. argentea (Salicion arenariae)Embryonic shifting dunesAtlantic decalcified fixed dunes (Calluno–Ulicetea)Dunes with Hippophae rhamnoidesFixed dunes with herbaceous vegetation (grey dunes)Humid dune slacksMachairAnnual vegetation of drift lines Perennial vegetation of stony banksSalicornia and other annuals colonising mud and sandSpartina swards (Spartinion maritimae) Shifting dunes along the shoreline with Ammophila arenaria (white dunes)Vegetated sea cliffs of the Atlantic and Baltic coastsMediterranean and thermo-Atlantic halophilic scrubs (Sarcocornetea fruticosi)

Examples in Scotland

✔✔✔✔✔✔✘✔✘

✔✔✔✔✔✔✘✔✔✔✔✔✔✘✔✔✘ ✔ yes; ✘, no.

Far left: Brittlestarbed (Ophiothrixfragilis), Loch Duich.G. Saunders

Left: The Vadills,Shetland.G. Saunders


Species

FishesSea lamprey (Petromyzon marinus)River lamprey (Lampetra fluviatilis)Allis shad (Alosa alosa)Twaite shad (Alosa fallax)

MammalsBottlenose dolphin (Tursiops truncatus)Harbour porpoise (Phocoena phocoena)Otter (Lutra lutra)Grey seal (Halichoerus grypus)Harbour or common seal (Phoca vitulina)

PlantsShore dock (Rumex rupestris)

Presentin Scotland

✔✔✔✔

✔✔✔✔✔

✘✔ yes; ✘, no.

plants or animals as set out in Annex I andAnnex II of the Directive. Scotland’s territorialwaters support seven of the nine marine and allbut three of the coastal Annex I habitats (Table2.1), together with nine of the ten marine AnnexII species (Table 2.2).

Table 2.2Habitats Directive Annex II marine, estuarine and coastal species

A proposal has been submitted to the UnitedNations Education, Scientific and CulturalOrganisation (UNESCO) to extend the St KildaWorld Heritage Site to encompass thesurrounding sea and sea bed (Box 2.2).

Allis Shad.NHPA

Bottlenose dolphins.D.Whitaker


Box 2.2 St Kilda WorldHeritage Site

The St Kilda archipelago represents theremnants of a long extinct ring volcanorising from a seabed plateauapproximately 40 m below sea level(Scottish Executive, 2003). It is a WorldHeritage Site in view of its outstandingterrestrial natural heritage and globallyimportant seabird colonies. The presentsite boundary encompasses the purelyterrestrial components, somewhat lessthan 1,000 ha in extent.

The submarine elements remainedundiscovered until recent surveysrevealed a remarkable assemblage offeatures, more or less devoid of humanimpact. Changing sea levels during theQuaternary are apparent as submergedcoasts. The influence of the north-eastAtlantic Drift means that a number ofnorthern species reach the southernextreme of their range there and viceversa. In view of the global importanceof the marine elements, a proposal has been put forward to extend World Heritage Site status to around 24,000 ha overall.

Far left: Stac Lee, St Kilda.J.Baxter

Left: Revised Nomination of St Kildafor inclusion in the World HeritageSite List.

Below: Underwater – St Kilda.R.Holt/MNCR/SNH


Issues and implicationsA comparison of North Sea coastal developmentin 1988 with that of 1999 revealed little change,other than an increase in the relative importanceof leisure and recreational uses (Ritchie andMcLean, 1988; Ritchie, 1999).

The benefits of the use of SSSI and other typesof designations in conservation management arebecoming evident. Ritchie (1999) observed thatover the last 30 years there has been a culturalchange towards conserving and enhancing theenvironment. With direct conservationmanagement applied to large areas of the easternScottish coastline, he observed that ‘… thecoastline is cleaner, more scenic, better managedand aesthetically conserved.’

SSSI, however, carry a major constraint that limitstheir effectiveness within the marine zone. Sincetheir inception they have explicitly excluded thearea below the mean low-water spring tides(Scottish Office, 1998), thus excluding a keycomponent of Scotland’s maritime naturalheritage from conservation managementlegislation.

In November 1999, as a result of a case initiatedby the environmental pressure group Greenpeace,the UK High Court ruled that the HabitatsDirective applied to ‘the UK continental shelfand superadjacent waters up to a limit of 200nautical miles’. Prior to this, designations underthe Habitats Directive were limited to sites withinthe 12-mile limit of UK territorial waters. Thisaction was stimulated by concern over the latestin a series of rounds in which the UKgovernment was considering granting licences

allowing seismic surveying and exploratorydrilling for the presence of oil and gas deposits.The area under greatest scrutiny lies to the northand west of the Hebrides, Shetland and OrkneyIsles. This is considered to be a region of majorimportance for large cetaceans, a groupparticularly vulnerable to seismic surveys but notincluded in Annex II of the Habitats Directive.The deep waters off the continental shelf break,although not well studied, are known to support awide range of habitats ranging from mudplainsand undulating sandbanks to reefs dominated bycoldwater corals. Such rocky reef habitats are aqualifying feature under Annex I of the HabitatsDirective.

The perceived threat posed by deep-sea oil andgas exploration is small when compared with amore immediate problem of deep-water fishing,an activity that currently lies outside thejurisdiction of the United Kingdom’s applicationof the Habitats Directive.

In 1994, as a direct response to the 1992 UnitedNations Convention on Biological Diversity, theUK government convened a Biodiversity SteeringGroup and published Biodiversity: The UK Action

Plan. Subsequently, specific Action Plans wereprepared for a range of UK species and habitatsthat are considered to be representative, rare or atrisk (Box 2.3). The marine environment is wellrepresented, with around 25% of the identifiedpriority habitats (Mackey et al., 2001). Overall, 81marine, estuarine or brackish-water species areincorporated within Action Plans, and about 74of these species are found around Scottish coasts(UK Biodiversity Group, 1999).

Bass Rock, Forth IslandsSPA.P. & A. Macdonald/SNH


Habitat/speciesLophelia pertusa reefsMaerl bedsMud habitats in deep waterSabellaria alveolata reefsSheltered muddy gravels Tidal rapids Basking shark (Cetorhinus maximus)Commercial marine fishCommon skate (Raja batis)Fan shell (Atrina fragilis)Native oyster (Ostrea edulis)Northern hatchett shell (Thyasira gouldi)Sea-fan anemone (Amphianthus dohrnii)

Scottish trendNo informationStableDeclining (slowing)No informationUnknownNo informationFluctuating/no clear trendNo informationNo informationDeclining (slowing)Declining (slowing)Declining (continuing/accelerating)No information

UK trendDeclining (continuing/accelerating)StableUnknownFluctuating/no clear trendDeclining (slowing)Declining (slowing)Fluctuating/No clear trendDeclining (continuing/accelerating)Declining (continuing/accelerating)Declining (slowing)UnknownDeclining (continuing/accelerating)Fluctuating/no clear trend

Trends

An assessment of status was published in 2003(http://www.ukbap.org.uk/asp/2002_main.asp).Trends were reported for five habitats and sixspecies at the UK level; and for two habitats andfour species at the Scottish level. Trends assessedare as follows:

Box 2.3 Biodiversity Action Plan

Action plans have been prepared for 13 marinehabitats and for 17 marine species or groups ofspecies occurring in Scottish waters (UKBiodiversity Group, 1999).The 13 marine habitats are Lophelia pertusa reefs,maerl beds, Modiolus modiolus beds, mud habitatsin deep water, mudflats, Sabellaria alveolata reefs,Sabellaria spinulosa reefs, saline lagoons, seagrassbeds, Serpulid reefs, sheltered muddy gravels,sublittoral sands and gravels, and tidal rapids.The 17 priority marine species or species groupscomprise vertebrates (9), invertebrates (7) and non-vascular plants (1). The vertebrates are baleenwhales (grouped plan), basking shark (Cetorhinusmaximus), deep-water fish (grouped plan), marineturtles (grouped plan), harbour porpoise (Phocoenaphocoena), common skate (Raja batis), commercial

marine fish (grouped plan), small dolphins(grouped plan), and toothed whales (groupedplan). The invertebrates are the sea-fan anemone(Amphianthus dohrnii), fan shell (Atrina fragilis),sea pen (Funiculina quadrangularis), native oyster(Ostrea edulis), sea squirt (Styela gelatinosa),lagoon sea slug (Tenellia adspersa) and northernhatchett shell (Thyasira gouldi). The non-vascularplant is the egg-wrack (Ascophyllum nodosum ecadmackaii).


Sources of dataA database of SSSI extents, feature(s) of interestand status is maintained by SNH.

ReferencesDEFRA. (2003). The Offshore Marine Conservation(Natural Habitats, &c.) Regulations 2003: AConsultation Document. Department forEnvironment, Food and Rural Affairs, London.

Mackey, E. C., Shaw, P., Holbrook, J., Shewry, M.C., Saunders, G., Hall, J. and Ellis, N. (2001).Natural Heritage Trends: Scotland 2001. ScottishNatural Heritage, Perth.

Ritchie, W. (1999). The Environmental Impact ofChanging Uses on the North Sea Littoral ofScotland. Denmark and Scotland: the Cultural andEnvironmental Resources of Small Nations. Jointsymposium of the Royal Society of Edinburgh andthe Royal Danish Academy of Sciences and Letters,15–18 September, 1999, Copenhagen.

Ritchie, W. and McLean, L. (1988). UK – Scotland.In: Artificial Structures and Shorelines. Walker, H.J. (ed.), pp. 127–135. Kluwer, Dordrecht.

Scottish Executive. (2003). Revised Nomination ofSt Kilda for Inclusion in the World Heritage SiteList. Scottish Executive, Edinburgh.

SNH. (2003). SNH Facts and Figures2002/2003. Scottish Natural Heritage, Battleby,Perth.

Scottish Office. (1998). People and nature. A newapproach to SSSI designations in Scotland. TheScottish Office, Edinburgh.

UK Biodiversity Group. (1999). Tranche 2 ActionPlans. Vol. V: Maritime Species and Habitats.English Nature, Peterborough.


Marine LifePart 2


Sharks, skates and rays3

IntroductionSharks, skates and rays together make up thegroup of cartilaginous fish (jawed fish with askeleton composed primarily of cartilage) knownas the elasmobranchs. The number of species inBritish waters is uncertain, but recent listingssuggest 30 sharks and 21 skates and rays.

Common nameCommon skateLong-nosed skateStarry skateElectric rayBlonde rayThornback raySandy rayShagreen rayRound raySpotted rayCuckoo ray

Species nameDipturus batisDipturus oxyrhinchusAmblyraja radiataTorpedo nobilianaRaja brachyuraRaja clavataLeucoraja circularisLeucoraja fullonicaRajella fyllaeRaja montaguiLeucoraja naevus

Table 3.1 Scottish skates and raysSource: A. Hood, The Shark Trust, personal communication, 2003

Records for skates and rays include 11 species inScottish coastal waters (Table 3.1).

At least 18 species of shark occur in Scottishwaters (Table 3.2), varying in size from the smalldogfish to the second largest fish in the world,the basking shark (the largest is the whale shark,Rhincodon typus, which occurs in tropical and warmtemperate seas).

Previous page: Cuckoo wrasse (Labrus mixtus).R. Holt

Above right: Common skate.P. Kay

Right: Spotted ray.R.Holt


Common nameFrilled sharkSix-gilled sharkBramble sharkDarkie charlieGreenland sharkSpurdog Thresher sharkBasking sharkShortfin mako sharkPorbeagle sharkBlack-mouthed dogfishLesser spotted dogfishNurse houndTopeSmooth houndStarry smooth houndBlue sharkAngel shark

Species nameChlamydoselachus anguineusHexanchus griseusEchinorhinus brucusDalatias lichaSomniosus microcephalusSqualus acanthiasAlopias vulpinusCetorhinus maximusIsurus oxyrinchusLamma nasusGaleus melastomusScyliorhinus caniculaScyliorhinus stellarisGaleorhinus galeusMustelus mustelusMustelus asteriasPrionance glaucaSquatina squatina

Table 3.2 Scottish sharks Source: A. Hood, The Shark Trust, personal communication, 2003.

TrendsExamination of the catch rates of rays fromNorth Sea fishery survey data for 1929–1939 and1991–1995 reveals a shift towards fewer speciesand smaller individuals (Walker, 1996). Majorchanges in the relative abundance of the eight rayspecies found in UK waters occurred over thisperiod, possibly as a result of changes in size atmaturity and thus vulnerability to capture. Due toits size, the common skate appears to beespecially vulnerable (Box 3.1).

Box 3.1 Common skate

Brander (1981) and Walker (1996) noteda decline in catches of common skate(Raja batis) in the Irish Sea and North Searespectively. Abundant in the past, thecommon skate was a commerciallyimportant component of the retainedbycatch. The largest among UK skate andray species, the common skate is nowconsidered to be commercially extinct inmost areas.

As part of the Fourth Quinquennial Review ofSchedules 5 and 8 of the Wildlife andCountryside Act, 1981, in 2002 the Joint NatureConservation Committee recommended that theangel shark and long-nosed and common skatesshould be granted full protection under Schedule5. The black and the white skates, which have notbeen recorded in Scottish coastal waters, werealso proposed. Statutory protection is needed forthese species, which are all reported to bedeclining in British waters.

Globally, the status of the basking shark (Box3.2) is assessed as vulnerable on the 1996International Union for Conservation of Natureand Natural Resources (IUCN) Red List ofThreatened Animals. Basking sharks have beenprotected within British territorial waters underthe Wildlife and Countryside Act (1981) since1998, and identified for conservation actionthrough a Species Biodiversity Action Plan. In2000, a UK proposal to place basking shark onAppendix II of the Convention on InternationalTrade in Endangered Species of Wild Fauna andFlora (CITES) was narrowly defeated, but afurther attempt in 2002 was successful. In theinterim, the UK has placed this species onAppendix III of CITES, banning other countriesfrom importing basking shark products from theUK without a valid export licence.

Basking shark P.Kay


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Figure 3.2Targeted basking shark landings. (a) North-east Atlantic. (b) Scotland only.

Basking shark.J. Leaver/Kelpie Design

Box 3.2 Basking shark

Basking sharks occur in the temperatewaters of most seas and are present inboth the northern and southernhemispheres. They are widelydistributed but are infrequentlyrecorded, except in a few coastalareas, where they are sometimes seenin relatively large numbers.

Basking sharks are seasonal visitors toScottish coastal waters, observedmainly on the west coast in summer,with sightings peaking around August.Movements are thought to bemigratory and in response to thesharks’ zooplankton food source. Long-

distance tracking of individuals hasbeen achieved only very recently. Whilethis has dispelled a long-held belief thatbasking sharks may hibernate in deeperwater, questions remain about migrationpatterns. It is not currently known if thereis a migration from deep to shallowwater or from lower to higher latitudes,or both. The presence, in basking sharklivers, of moderately high levels ofsqualene, a chemical characteristic ofdeep-water species, suggests that a partof their life history is spent in deepwater.

Accurate and reliable quantitative dataon basking shark populations in Scottishwaters are not available. However, theMarine Conservation Society (MCS)initiated a reporting scheme for publicparticipation in 1987. These data(Figure 3.1) indicate a substantial UKand Scottish peak in sightings in 1989and 1990 respectively, with asubsequent large decline in sightingsduring the following 2–3 years. Asecond peak for Scottish sightings in1996 was not reflected by overall UKobservations. It is likely, though, that thedata have been influenced by the timingand level of active promotion of the

reporting scheme. Higher mediapromotion occurred in 1988, 1989,1990, 1991, 1995 and 1996(Nicholson et al., 2000).

The basking shark has been exploitedfor several centuries, initially for thehigh oil content of the liver, which wasused in the steel, medical, cosmeticand tanning industries as well as a fuelfor lighting. While there has beenlimited growth in its use in cosmeticand health supplement products, it hasbeen the demand and associated highprices paid for shark fin in Asianmarkets that has been the majordriving force behind recent baskingshark catches.

Throughout the north-east Atlantic,large numbers were caught betweenthe mid-1940s and early 1980s(Figure 3.2), particularly by theNorwegian fleet. In the 1980s and1990s catch levels were much reduceddespite the high demand for shark fin(ICES, 1995; Anon., 2000). Severalrecent attempts to establish a Scottishfishery based in the Minch and Clydeareas failed because of marketingdifficulties and widely fluctuating shark


Geographical area anddescription of records

Achill Island, Ireland, atargeted coastal baskingshark fishery

West coast of Scotland

Firth of Clyde, Scotland

Norwegian catches

North-east Atlantic (allcatches combined)

Overall (decline) or increase incatches

>95% decline in 25 years

~30% in 7 years, but trend unclear

>90% in 12 years

87% decline from peak landings inlate 1960s to levels in the early 1990s

90% decline from the main period ofpeak landings in the late 1960s tolandings in the late 1980s. Thisfollowed 20 years of fluctuating butrising catches

Average catches orsightings per year

360/year in 1947–19501,475/year in 1951–1955489/year in 1956–1960107/year in 1961–196564/year in 1966–197050/year in 1971–1975Rarely seen in 1990s

121/year throughout fishery142/year in 1946–1949100/year in 1950–1953

58.6/year in first 5 years4.8/year in last 5 years

837/year in 1946–1950554/year in 1951–19551,541/year in 1956–19601,792/year in 1961–19653,213/year in 1966–19702,236/year in 1971–19751,706/year in 1976–1980797/year in 1981–1985343/year in 1986–1990403/year in 1991–1995

1,254/year in 1946–19502,094/year in 1951–19552,030/year in 1956–19601,899/year in 1961–19653,277/year in 1966–19702,385/year in 1971–19751,706/year in 1976–1980848/year in 1981–1985355/year in 1986–1990407/year in 1991–1995

Time scale

1947–1975

1946–1953

1982–1994

1946–1996

1946–1996

Table 3.3 Trends in basking shark fisheriesSources: Fairfax, 1998; Kunzlik, 1998; Anon.,2000; Nicholson et al., 2000).

numbers (Fairfax, 1998; Kunzlik, 1998)(Table 3.3).

Although the influence of natural cyclicalfactors makes assessments of populationtrends difficult, it is thought that theirbiology and site-faithfulness makebasking sharks particularly vulnerable tooverexploitation. Some directed fisheries

have seen catch declines of 50% to over80% within a decade (Table 3.3). Therehas been no subsequent populationrecovery, indicating that there is little orno migration of individuals from otherareas.

There are no regular, scientificallysupported surveys of basking sharkabundance in UK waters. Little is knownof basking shark life history, feedingecology and migration habits. Furtherstudy is essential to determine their

present status in Scottish waters. InFebruary 2001, a three-year projectfunded jointly by DEFRA, CEFAS andMBA was initiated to provide newinformation about the movements,distribution and population dynamics ofbasking sharks in European waters,combining data from archival satellitetags with sighting, stranding andfisheries records.


Issues and implicationsScottish coastal waters hold at least 18 species ofshark, eight species of ray and three species ofskate. Improved knowledge and conservationmeasures are required for their preservation.Vulnerable to commercial exploitation, severalspecies have shown declines and four now meritstatutory protection. The biggest among them –the common skate and the basking shark – havebeen pushed to commercial extinction.

Sources of dataConsiderable reliance on catch data has providedan incomplete picture of the status and ecologyof sharks, rays and skates in the seas aroundScotland. Satellite tagging, combined withsighting, stranding and fisheries data, is leading toan improved understanding of the movements,distribution and population dynamics of baskingshark in European waters.

ReferencesAnon. (2000). Proposal to Include the BaskingShark (Cetorhinus maximus) on Appendix II of theConvention on International Trade in EndangeredSpecies (CITES). UK submission to the 11thMeeting of the Conference of CITES parties (Cop11), Kenya, 1999.

Brander, K. (1981). Disappearance of the commonskate, Raja batis, from the Irish Sea. Nature 290:48–50.

Fairfax, D. (1998). The Basking Shark in Scotland.Natural History, Fishery and Conservation. TuckwellPress, East Linton, Scotland.

ICES. (1995). Report of the Study Group onElasmobranch Fishes. CM 1995/G: 3.International Council for the Exploration of the Sea,Denmark.

Kunzlik, P. A. (1998). The Basking Shark. ScottishInformation Pamphlet, No. 14. Department ofAgriculture and Fisheries for Scotland, Aberdeen.

Nicholson, D., Harris, E. and Pollard, S. (2000).The Location and Usage of Sites in Scotland by theBasking Shark Cetorhinus maximus. ScottishNatural Heritage, commissioned report(unpublished), F99AA402. Scottish NaturalHeritage, Edinburgh.

Walker, P. (1996). Sensitive Skates or ResilientRays? Spatial and Temporal Shifts in Ray SpeciesComposition in the Central and NorthwesternNorth Sea. CM 1996/Mini: 4. InternationalCouncil for the Exploration of the Sea, Denmark.


Dolphins, porpoises and whales4

IntroductionTwenty-five species of cetacean (dolphins,porpoises and whales) have been recorded inBritish and Irish waters within the last 100 years,and 23 within the last 25 years (Evans, 1992). Ofthese, 22 species have been sighted alive andreported more than once around Scotland.Surveys carried out between 1979 and 1998 offthe north and west of Scotland by the JointNature Conservation Committee (JNCC)Seabirds at Sea Team recorded 15 species (Weir etal., 2001). An overview of species occurringwithin Scottish waters, combining informationfrom several sources, is given in Table 4.1.

In the past, commercial whaling activities reducedpopulations of target species throughout thenorth-east Atlantic and northern North Sea.Although quantitative estimates of the scale ofsuch reductions are not possible, anecdotalevidence combined with catch records suggestthat sperm (Physeter macrocephalus) and sei(Balaenoptera borealis) whales sustained at leastmoderate population reductions, while blue whale(Balaenoptera musculus), fin whale (Balaenoptera

physalus), humpback whale (Megaptera novaengliae)and northern right whale (Eubalaena glacialis)populations were greatly reduced (Thompson,1928; Brown, 1976; Evans, 1992).

A Norwegian-owned commercial whalingoperation, established in Loch Tarbert, Harris,around 1903, operated from 1904 to 1928 andbriefly reopened between 1950 and 1951. Catchrecords and reported impacts of the widerindustry are given in Table 4.2. A globalmoratorium on commercial whaling was imposedby the International Whaling Commission (IWC)in 1986. Norway lodged a formal objection andresumed exploitation of North Atlantic minkewhale in 1993, taking 153 whales in the first year,increasing to 580 in 1997. A Norwegian nationalquota of 711 was set for 2003.

Cetaceans are currently protected throughoutBritish waters under the Wildlife and CountrysideAct (1981, reviewed 1986) and the WhalingIndustry (Regulation) Act (1934, as amended1981). The Nature Conservation (Scotland) Bill,which is expected to be enacted in 2004, willstrengthen the existing legislation by including aprovision for prosecuting those who cause harmor harassment through ‘recklessness’, whereaspreviously an intention had to be proven.

TrendsFew data are available for robust assessments ofcetacean population trends. The OSPARCommission (2000) reported that, following themoratorium on commercial whaling, most speciesof large whale are showing signs of recovery inEuropean waters.

Bottlenose dolphin (Tursiops truncatus).D. Whitaker

Sperm whale (Physetermacrocephalus), Forth estuary.

E. Mackey

White-beaked dolphin(Lagenorhynchusalbirostris), Forth

estuary.E. Mackey


Table 4.1 Status of cetacean species occurring in Scottish watersSources: Evans et al., 1986; Evans, 1992; Hammond et al., 1995; Shrimpton and Parsons, 1999; Reid et al., 2003.

Species

Harbour porpoise(Phocoena phocoena)

Bottlenose dolphin (Tursiops truncatus)

Risso’s dolphin (Grampus griseus)

White-beaked dolphin(Lagenorhynchus albirostris)

Atlantic white-sided dolphin(Lagenorhynchus acutus)

Common dolphin (Delphinus delphis)

Striped dolphin (Stenella coeruleoalba)

Northern bottlenose whale(Hyperdoon ampullatus)

Cuvier’s beaked whale(Ziphius cavirostris)

Sowerby’s beaked whale(Mesoplodon bidens)

True’s beaked whale(Mesoplodon mirus)

Beluga or white whale(Delphinapterus leucas)

Killer whale (Orcinus orca)

False killer whale (Pseudorca crassidens)

Long-finned pilot whale (Globicephala melas)

Sperm whale (Physeter macrocephalus)

Blue whale (Balaenoptera musculus)

Fin whale (Balaenoptera physalus)

Sei whale (Balaenoptera borealis)

Minke whale (Balaenoptera acutorostrata)

Humpback whale(Megaptera novaengliae)

Northern right whale(Eubalaena glacialis)

Evidence for populationincrease/decline

Decline (North Sea)

Decline, perhaps due partlyto changing distribution

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Unknown

Recovery (central NorthAtlantic)

Unknown

Unknown

Unknown

Recovery

Decline

Abundance estimate

Approx. 150,000 in UKwaters (1994)

Approx. 130 in the MorayFirth (1999)

42 individuals identified in theMinch (1999)

Approx. 7,800 in North Seaand English Channel (1994)

Approx. 74,600 off north-westand west Scotland (1998)

None

None

None

None

None

None

None (only 14 live sightings)

3,500–12,500 in easternNorth Atlantic (1990)

None (only four live sightings)

Approx. 778,000 in NorthAtlantic (1987–1989)

None

None

Approx. 47,300 in NorthAtlantic (1992)

None

Approx. 8,400 in North Sea,Celtic Sea and Skagerrak(1994), 112,000 in easternNorth Atlantic (1995)

10,000–15,000 in NorthAtlantic in 1992–1993

Extremely rare or possiblyextinct in eastern NorthAtlantic

Occurrence

Common in both inshore andoffshore shelf water

Locally frequent in inshorewaters

Locally frequent in inshorewaters

Frequent in both inshore andoffshore shelf waters

Common in offshore waters

Seasonally frequent inoffshore waters, locallyfrequent in inshore waters

Rare

Uncommon in offshore waters

Rare

Rare

Very rare

Very rare

Frequent in offshore waters,locally frequent in inshorewaters

Very rare

Common in offshore waters,occasional in inshore waters

Frequent in offshore waters

Rare

Frequent in offshore waters

Occasional in offshore waters(NB: highly variable betweenyears)

Frequent in both inshore andoffshore shelf waters

Rare

Very rare


Species

Northern bottlenose whale (Hyperdoonampullatus)

Sperm whale (Physeter macrocephalus)

Blue whale (Balaenoptera musculus)

Fin whale (Balaenoptera physalus)

Sei whale (Balaenoptera borealis)

Minke whale* (Balaenoptera acutorostrata)

Humpback whale (Megaptera novaengliae)

Northern right whale (Eubalaena glacialis)

Shetland(1903–1928)

25

19

85

4,536

1,839

–

51

6

OuterHebrides(1903–1928)

1

76

310

1,492

375

–

19

94

Outer Hebrides(1950–1951)

0

1

6

46

3

–

0

0

Populationreduction bywhaling

Uncertain

Reduced

Greatly reduced

Greatly reduced

Reduced

Uncertain

Greatly reduced

Greatly reduced

Scottish catch records

Recorded UK and Irish cetacean strandingsincreased steadily between the 1960s and 1980s,possibly reflecting increased population sizes. Itshould be noted that these are reportedstrandings, and some caution must be appliedwhen relating these figures to the true number oftotal stranding events. Otherwise, there is verylittle direct evidence on which to baseunequivocal statements of any populationrecovery. Formal recording of strandings aroundScotland began in 1992. Between 1992 and 1995Scottish strandings accounted for about 60% ofthe UK total (Mayer, 1996). In the period up to2002, stranding events of both large and smallcetacea showed little change (Figure 4.1).Similarly, there was little change in the proportionof species stranded (Figure 4.2), with the overallnumbers broadly reflecting the prevalence ofspecies around Scotland.

The Moray Firth is host to the world’s mostnortherly population of bottlenose dolphin(Tursiops truncatus) and the only known ‘resident’population of this species in the North Sea.Statistical studies suggest that this is an isolated,barely viable population, which may be in decline

*Not targeted by Scottish fishery but taken by Norwegian vessels around the Northern Isles.

0

20

40

60

80

100

120

140

160

180

200

200220001998199619941992

YEAR

NU

MBE

R O

F ST

RAN

DIN

GS

Figure 4.1Total recorded Scottish cetacean strandings (1992–2002) Source: Scottish Agricultural College.

Risso’s dolphins.C. MacLeod/Seapics

Far right: Humpbackwhale.A. Rouse

Table 4.2Scottish whaling catch records 1903-1951.Sources: Thompson, 1928; Brown, 1976; Evans, 1992.


(Sanders-Reed et al., 1999). Part of the apparentdecline may be accounted for by a change in thedistribution of the population, having beingsighted also in the Firths of Tay and Forth.

Issues and implicationsSmaller whales, dolphins and porpoises haveremained largely unaffected by direct commercialexploitation. They have nevertheless been facedwith a range of threats from other sources, thegreatest of which is entanglement in fishing gear.Studies of incidental catches are few but indicatethat porpoises and dolphins are at greatest riskfrom bottom set nets and pelagic trawlsrespectively. Estimates for a range of north-eastern Atlantic pelagic trawl fisheries arrived at acatch rate of one dolphin for every 98 hours oftowing (Morizur et al., 1999).

Box 4.1 UK small cetacean bycatchresponse strategy

The strategy reviews fisheries interactions with smallcetaceans in UK waters and the need to reduce bycatchof small cetaceans in general and harbour porpoises inparticular. It recognises work that has been carried outwith the support and cooperation of the fishing industry toidentify where bycatch is a problem. It establishes bycatchreduction targets for specific fisheries over the next threeyears and makes recommendations as to mitigationtechniques that should be employed by these fisheries.Key recommendations relate to compulsory use ofacoustic pingers in certain fisheries, the need for aneffective observer scheme, continued research intopractical and cost-effective mitigation measures and theneed to support further surveys to enable a betterunderstanding of small cetacean abundance anddistribution in UK waters.

0 10 20 30 40 50

20021997

1992

PROPORTION OF STRANDINGS (%)

Harbour Porpoise

Minke Whale

Atlantic White-sided Dolphin

White-beaked Dolphin

Long-finned Pilot Whale

Common Dolphin

Sperm Whale

Risso's Dolphin

Striped Dolphin

Bottlenose Dolphin

Figure 4.2The 10 species most commonly stranded on Scottish coasts represented as apercentage of all Scottish strandings for 1992, 1997 and 2002.

Whaling harpoon, Leith docks, Edinburgh.J. Baxter

Above: Dundee whaling fleet leaving port for a voyage to the DavisStraits about the turn of the 19th-20th century. Dundee Museum

Harbour porpoise (Phocoena phocoena)stranding. P. Kay


The harbour porpoise (Phocoena phocoena) is themost abundant of the Scottish cetaceans, withthe highest reported concentrations around thewestern and north-eastern coasts (Evans, 1992,1997). A survey of North Sea harbour porpoisein 1994 estimated a population size of around300,000 (Hammond et al., 1995). Of these, some7,000 per year are thought to have perished as aresult of incidental capture in the Danish gillnetfishery alone (Lowry and Teilmann, 1994;Vinther, 1995). Overall, fishery-related mortalityof harbour porpoise is believed annually toexceed 2% of the total North Sea population, arate considered by the IWC to be unsustainable.As a first step towards a marine mammalconservation strategy, the Agreement on SmallCetaceans of the Baltic and North Seas(ASCOBANS) has recently pressed the EC torestrict incidental capture to less than 1.7% peryear. Additional data on the rate of incidentalcapture specifically relating to Scottish fisheriesare currently being gathered with the cooperationof a number of skippers of Scottish fishingvessels. The UK small cetacean bycatch responsestrategy (Box 4.1) sets out proposals to helptackle this issue (DEFRA, 2003).

Pollution of the marine environment hasincreased greatly in the last 100 years.Organochlorines such as dichlorodiphenyl-trichloroethane (DDT), polychlorinated biphenyls(PCBs) (and their metabolites and impurities) andother man-made chemicals are more soluble infat than in water and so will accumulate to highlevels in animals that rely on blubber as an energystore. At critical concentrations, an interactionwith an animal’s hormonal system may occur,resulting in reduced reproductive performanceand disease resistance. The manufacture of manyof these chemicals has been strictly controlled inEurope for over 20 years, but careless disposal,leakage from storage sites and persistence inmarine sediments has resulted in a continuedaccumulation in marine mammals. Comparativelyhigher levels are found in coastal species that areat or close to the top of the food chain. Levelsfound in cetaceans from the west of Scotland arelower than those found in the North Sea(Shrimpton and Parsons, 1999). Trace metal levelsmeasured in resident Scottish cetaceans are notconsidered high when compared with thoseobserved for marine mammals world-wide.

Noise from marine traffic, military activity,coastal industry and oil exploration andproduction is thought to cause varying levels ofdisruption to cetacean activity. Shock waves andexplosions may cause direct tissue damage andpermanent auditory organ damage. An increase in

background noise can interfere with acousticcommunication, reducing the distance over whichsuch communication can take place. AroundScotland, overall seismic activity associated withoil exploration has increased since 1994. A codeof practice, Guidelines for Minimising Acoustic

Disturbance to Small Cetaceans from Seismic Surveys,was introduced by the UK government in 1998.

The depletion of herring stocks may haveresulted in the decline of UK harbour porpoisepopulations during the last 50 years (Evans, 1990;Hammond et al., 1995). The recovery of herringstocks following a fishing ban in 1977 wasfollowed by a slight increase in sightings ofharbour porpoises. In the 1980s there was adecline in both seabird and harbour porpoisenumbers in Shetland coastal waters, coincidingwith successive years of poor recruitment ofsandeels into the adult population (Evans, 1997).

In terms of interaction with man-made marinedebris, entanglement, particularly in discarded orlost fishing gears, constitutes the greatest hazard(Laist, 1997; Gill et al., 2000). Scars caused byrope or net abrasion are regularly seen, butevidence of incidents in which entanglement hasresulted in death by drowning or suffocation isrelatively rare, largely because the majority ofthese events occur below the sea surface.Ingestion of debris also occurs, but the availableevidence suggests that this is not as common asentanglement and is far less likely to result indeath (Laist, 1997)

Collision with marine vessels is known to occur,but the frequency of occurrence and the extentof injuries sustained are unknown. Codes ofconduct to minimise the impacts fromrecreational sea users were introduced by the UKgovernment in 1999: Guidelines for Minimising

Disturbance to Cetaceans from Recreation at Sea andMinimising Disturbance to Cetaceans from Whale

Watching.

Although knowledge of the distribution andecology of the cetacea found in Scottish waters isimproving, population trend data are few. Theglobal debate on the resumption of commercialwhaling continues to be dominated bydisagreements on the size and stability of targetwhale populations.

Sources of dataThe precise population status of most cetaceaoccurring in Scottish waters, and indeed thosearound the whole of the UK, is largely unknown,with reliable scientific data restricted toobservations on distribution rather than


numerical abundance. The Joint CetaceanDatabase (JCD) is a repository of sightings datarecently created by merging three databasespreviously held separately by the Sea WatchFoundation, the JNCC and the Sea MammalResearch Unit (SMRU). A product of this (Box4.2) is the recently published Atlas of Cetacean

Distribution in North-West European Waters (Reid etal., 2003).

Records for Scottish cetacean strandings arecompiled annually by the Scottish AgriculturalCollege Veterinary Investigations Centre.Systematic collation began in 1992.

Box 4.2 Atlas of CetaceanDistribution in North-WestEuropean Waters

The Atlas (Reid et al., 2003) providesa comprehensive account of thedistribution of all species of cetaceanknown to have occurred in the watersoff north-west Europe in the last 25years. Individual species accountsinclude information on identification,behaviour and social organisation,diet and habitat preferences.Distribution maps for each speciesare based on data in the JointCetacean Database, with contextinformation on global distribution andstatus in north-west Europe.

ReferencesBrown, S. G. (1976). Modern whaling in Britain and thenorth-east Atlantic Ocean. Mammal Review 6: 25–36.DEFRA. (2003). UK Small Cetacean Bycatch responseStrategy. A consultation paper outlining the proposed strategyby the Department for Environment, Food and Rural Affairs,the Scottish Executive, the Welsh Assembly Government andthe Department of Agriculture and Rural Development inNorthern Ireland to reduce the incidental capture of smallcetaceans in UK fisheries. Department for Environment, Foodand Rural Affairs, London.Evans, P. G. H. (1990). Harbour Porpoise (Phocoenaphocoena) in British and Irish Waters. Paper submitted to theIWC Scientific Committee meeting, June 1990.Evans, P. G. H. (1992). Status Review of Cetaceans in Britishand Irish Waters. Report to the UK Department of theEnvironment, London. Sea Watch Foundation, Oxford.Evans, P. G. H. (1997). Ecological Studies of the HarbourPorpoise in Shetland, North Scotland: Final Report. SeaWatch Foundation, report for WWF-UK, Oxford.Evans, P. G. H., Harding, S., Tyler, G. and Hall, S. (1986).Analysis of Cetacean Sightings in the British Isles,1958–1985. CSD Report No. 892. Nature ConservancyCouncil, Peterborough.Gill, A., Reid, R. J. and Fairbairns, B. R. (2000). Photographicand strandings data highlighting the problem of marine debrisand creel rope entanglement to minke whales (Balaenopteraacutorostrata) and other marine life in Scottish waters. In:Proceedings of Fourteenth Annual Conference of EuropeanCetacean Society, 3–6 April 2000, Cork, Ireland.Hammond, P. S., Benke, H., Berggren, P., Borchers, D. L.,Buckland, S. T., Collet, A., Heide-Jørgensen, M. P., Heimlich-Boran, S., Hiby, A. R., Leopold, M. F. and Øien, N. (1995).Distribution and Abundance of the Harbour Porpoise andother Small Cetaceans in the North Sea and Adjacent Waters.Final Report, October 1995. Life Project, LIFE 92–2/UK/027.Laist, D. (1997). Impacts of marine debris: entanglement ofmarine life in marine debris including a comprehensive list ofspecies with entanglement and ingestion records. In: MarineDebris: Sources, Impacts and Solutions. Coe J. and Rogers, D.

B. (eds), pp. 99–119. Springer Verlag, New York.Lowry, N. and Teilmann, J. (1994). Bycatch and bycatchreduction of the harbour porpoise (Phocoena phocoena) inDanish waters. In: Report of the International WhalingCommission (Special Issue 15): 203–209.Mayer, S. (1996). A Review of Live Strandings of Cetaceans:Implications for Their Veterinary Care, Rescue andRehabilitation in the UK. Whale and Dolphin ConservationSociety, Bath.Morizur, Y., Berrow, S. D., Tregenza, N. J. C., Couperus, A.S. and Pouvreau, S. (1999). Incidental catches of marine-mammals in pelagic trawl fisheries of the northeast Atlantic.Fisheries Research 41: 297– 307.OSPAR Commission. (2000). Quality Status Report 2000.OSPAR Commission, London.Reid, J. B., Evans, P.G. H. and Northridge, S.P. (2003). Atlasof Cetacean Distribution in North-West European Waters.Joint Nature Conservation Committee, Peterborough.Sanders-Reed, C. A., Hammond, P. S., Grellier, K. andThompson, P. M. (1999). Development of a Population Modelfor Bottlenose Dolphins. Scottish Natural Heritage ResearchSurvey and Monitoring Report, No. 156. Scottish NaturalHeritage, Battleby, Perth.Shrimpton, J. H. and Parsons, E. C. M. (1999). CetaceanConservation in West Scotland. Hebridean Whale andDolphin Trust, Version 1.2.Thompson, D. A. (1928). On whales landed at the Scottishwhaling stations during the years 1908–1914 and1920–1927. Scientific Investigations Fishery Board ofScotland No. 3: 1–40.Vinther, M. (1995). Incidental catch of the harbour porpoise(Phocoena phocoena) in the Danish North Sea gill-netfisheries: preliminary results. Proceedings of the ScientificSymposium on the North Sea Quality Status Report 1993,1994. Ebeltoft, Danish Environmental Protection Agency,Copenhagen.Weir, C. R., Pollock, C., Cronin, C. and Taylor, S. (2001).Cetaceans of the Atlantic Frontier, north and west of Scotland.Continental Shelf Research 21: 1047–1071.


Seals5

IntroductionTwo species, the grey seal (Halichoerus grypus) andharbour or common seal (Phoca vitulina), arepresent around the coast of Scotland ininternationally important numbers. For thousandsof years they were hunted for their pelts, oil andmeat, but overexploitation by the early 1900sforced the establishment of a closed season forgrey seals to prevent extinction (McGillivray,1995). A UK-wide annual grey seal cull wasmaintained from 1962 until 1979, when it wasabandoned in the face of sustained publicprotest. Harbour seals continued to be hunted fortheir skins until the early 1970s, when up to 90%of pups were taken annually. A ban on UK furtrading was established in 1973.

UK coastal waters support some 40% of theEuropean harbour seal subspecies Phoca vitulina

vitulina and 5% of the world population. About90% of the UK harbour seal population is foundin Scottish waters (SMRU, 2001). In 1988, a viralepidemic swept through the North Sea harbourseal population. Phocine distemper virus (PDV)was previously unknown but is related to caninedistemper virus and the epidemic was probably anatural event, as similar epidemics are known tohave occurred in the past. The disease reducedoverall North Sea populations by over 40% and

was most severe along the continental coasts(OSPAR Commission, 2000). In England, 50% ofseals resident in The Wash were reported to havedied, but Scottish populations were less affected.Mortality estimates for the Moray Firthpopulations vary between 10% and 20%(Thompson and Miller, 1992), with some west-coast populations sustaining slightly greaterlosses.

In 2002, the British grey seal population wasestimated (to the nearest thousand) at 134,000animals aged one year or older (SCOS, 2003).About 40% of the world’s grey seals breed atwell-established sites around Britain. Of these,over 90% – some 122,000 – are associated withScottish coastal sites.

TrendsThroughout Europe and the UK, harbour sealnumbers have rapidly returned to, or exceed, pre-1988 epidemic levels. Between 1996 and 2001,around 29,700 harbour seals were counted inScotland (Table 5.1) out of a total of 33,700 inEngland and Scotland combined (SCOS, 2003).Periodic estimates at selected sites from the late1980s to the present suggest that populationshave remained largely stable, although regionalcounts show local fluctuations. Surveys carried

Below: Harbour seal.L. Gill/SNH

Below right: Grey sealwith satellite tag.J. Baxter


Region

Outer HebridesScottish west coastScottish east coastShetlandOrkneyScotland

Population status

Possibly increasingPossibly increasingStablePossibly decreasingPossibly decreasing

Years whenlatestinformationwas obtained1996–20001996–20001996–19971996–20011996–2001

Populationsize1

2,40012,8001,8004,9007,80029,700

Table 5.1 Sizes and status of European populations of harbour seals (numbers given pre-date the PDVepidemic of 2002)

Many of the population size estimates represent counts of seals. They should be considered as minimum estimates of totalpopulation size. Counts are rounded to the nearest 100 seals.

out by the University of Aberdeen suggest adecline in numbers in the Inner Moray Firth,while a 2001 population survey in Orkney andShetland suggested a reduction in numbers of9% and 18.5%, respectively, compared with the1997 counts (Scottish Executive web site).

A new outbreak of PDV in 2002, originating inDenmark, again affected UK harbour sealpopulations. Populations in The Wash were againmost badly affected. Sightings of dead, infectedanimals from around the coast of Scotland wererecorded. At this time it is not possible toquantify the scale of the impact of this newepidemic (SCOS, 2003). A Scotland-wideConservation Order for harbour seals was issuedfor an initial period of two years by the ScottishExecutive on 3 September 2002. The orderincluded grey seals within the Greater MorayFirth area only.

British grey seal populations increased steadilybetween 1984 and 1997, with an average rise ofabout 6% per year. This rate of increase wasmaintained at 5.6% between 1997 and 2001.Since the 1970s, pup production has increasedgreatly in the Orkney Isles and the OuterHebrides, with a lesser expansion in the InnerHebrides and North Sea (Figure 5.1). There issome evidence of a slow-down in the increase inpup production in recent years, with productionat the main breeding sites showing an averageincrease of around 2.8% between 1997 and 2002compared with 5.2% between 1992 and 1996 and6.2% between 1987 and 1991.

Issues and implicationsThe status of both grey and harbour seal iscurrently considered to be good, although theeffect of the 2002 PDV outbreak on Scottishharbour seal numbers cannot yet be predicted.

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

2004199919941989198419791974196919641959

YEAR

NU

MBE

R O

F G

REY

SEA

L PU

PS

North Sea

Orkney Isles

Outer Hebrides

Inner Hebrides

Figure 5.1 Grey seal pupproduction at mainbreeding sites Source: Sea MammalResearch Unit


The reasons for the sustained growth in the greyseal population are not known, but thedisproportionate rise in areas such as the OuterHebrides suggests that the availability of sitesfree of human disturbance may be a factor inbreeding success.

Both the fishing and fish farm industries haveexpressed concern with the increasing sealnumbers, arguing that this has led to increaseddamage to farmed stocks and fish cages and hascontributed to reductions in wild fish stocks. Thefishing industry has called for the initiation of aculling programme. At present, there are noscientific data to indicate that depletion of north-eastern Atlantic commercial fish stocks iscorrelated with changes in seal numbers.Estimates of seal, harbour porpoise and seabirdpredation on North Sea fish suggest an annualconsumption by each of 2–3% of the total fishbiomass (Saunders et al., 2002; see Figure 8.8).This compares with the removal of an estimated25–30% by the fishing industry (FifthInternational Conference on the Protection ofthe North Sea, 1997).

The debate surrounding grey seal populationgrowth and the need for culling to preservecommercial fish stocks will continue. Theinteraction between seals and fisheries iscomplex, incorporating scientific, environmental,social, cultural and economic considerations, butthe fundamental relationship between sealpopulation dynamics and fisheries has yet to beestablished. A number of research projectsdirected towards providing such data arecurrently underway at the SMRU.

Sources of dataUK seal populations are monitored regularly bythe SMRU on behalf of the NaturalEnvironment Research Council (NERC). TheNERC provides advice to the UK governmenton the size and status of the British sealpopulation under the Conservation of Seals Act,1970. This, together with the EC HabitatsDirective, provides protection to seals when theycome ashore to pup, breed and moult. Recentmonitoring has been carried out largely by aerialsurvey and mainly at Scottish locations. As sealsspend a large proportion of their time in theopen sea, counting is carried out at times ofgreatest shore-based activity; during puppingseason for grey seals and moulting for harbourseals. Total population estimates are derived fromthese data.

Recent data on seal populations are available onthe Scottish Executive web site.

ReferencesFifth International Conference on the Protection ofthe North Sea. (1997). Assessment report onfisheries and fisheries related species and habitatsissues. Report from the Committee of North SeaSenior Officials to the Intermediate MinisterialMeeting on the Integration of Fisheries and Environmental Issues, 1997 (IMM 97), Bergen.Table 5.1 Sizes and status of European populationsof harbour seals (numbers given pre-date the PDVepidemic of 2002).

McGillivray, D. (1995). Seal conservationlegislation in the UK – past, present, future. TheInternational Journal of Marine and Coastal Law10: 19–51.

OSPAR Commission. (2000). Quality Status Report2000, Region II – Greater North Sea. OSPARCommission, London.

Saunders, G., Dobson, J. and Edwards, A. (2002).The state of Scotland’s seas and estuaries. In: TheState of Scotland’s Environment and NaturalHeritage. Usher, M. B., Mackey, E. C. and Curran,J. C. (eds). The Stationery Office, Edinburgh.

SCOS. (2003). Scientific Advice on MattersRelated to the Management of Seal Populations:2003. Natural Environment Research CouncilSpecial Committee on Seals.

SMRU. (2001). Surveys of Harbour Seals on theWest and East Coasts of Scotland. Scottish NaturalHeritage, Commissioned Report, F00AA417. SeaMammal Research Unit, Edinburgh.

Thompson, P. M. and Miller, D. (1992). Phocinedistemper virus outbreak in the Moray Firthcommon seal population: an estimate of mortality.Science of the Total Environment 115: 57–65.

Figure 5.2Track of harbour sealtagged on Jura, 2004.Source: LouiseCunningham/SMRU


Seabirds

This chapter was prepared by P. Shaw (SNH).

6

IntroductionThe seas around Britain and Ireland are amongthe richest in the world for breeding seabirds,supporting almost 8 million birds of 25 species.Many of these have a high proportion of theirbreeding population in Scotland, which supports60% of the world’s great skuas (Catharacta skua),about half of the world’s northern gannets(Morus bassanus) and about one third of theworld’s Manx shearwaters (Puffinus puffinus)(Mitchell et al., 2004). Four species have morethan 95% of their combined British and Irishpopulation in Scotland, while 14 species havemore than half of their population in Scottishbreeding colonies. The latter include all four aukspecies, the northern fulmar (Fulmarus glacialis)and northern gannet, as well as great and Arcticskua (Stercorarius parasiticus). Most of those withless than half of their British population inScotland are gull or tern species.

TrendsThere have been three comprehensive seabirdcensuses in Britain spanning 30 years: 1969-70,1985-88 and 1998-2002. These are referred tohere as the ‘1970’, ‘1987’ and ‘2000’ census,respectively. They provide comparable estimatesfor 20 seabird species between 1970 and 1987,and for 21 species in Scotland between 1987 and2000. The most recent census, Seabird 2000,included some 3,200 colonies from 40,000 km ofthe coastline of Britain and Ireland (Mitchell et al.

2004). In Scotland, over 3.28 million seabirdswere counted, comprising 76% of the UK totaland 69% of the British and Irish total. Seabird

2000 provided the first comprehensive counts ofManx shearwater, European storm-petrel(Hydrobates pelagicus) and Leach’s storm-petrel(Oceanodroma leucorhoa). It included inland as wellas coastal colonies of great cormorant(Phalacrocorax carbo), black-headed gull (Larus

ridibundus), mew (common) gull (L. canus), lesserblack-backed gull (L. fuscus) and common tern

PERCENTAGE CHANGE

-100 -50 0 50 100 150 200 250

Great Skua (213%)

Common Guillemot (125%)

Arctic Skua (106%)

Northern Gannet (93%)

Lesser Black-Backed Gull* (79%)

Northern Fulmar (70%)

Mew Gull* (67%)

Gazorbill (25%)

Atlantic Puffin (20%)

Common Tern (12%)

Little Tern (7%)

Great Cormorant (5%)

Arctic Tern (2%)

Great Black-Backed Gull* (-7%)

Black-Legged Kittiwake (-18%)

European Shag (-21%)

Herring Gull* (-55%)

Sandwich Tern (-57%)

Black-Headed Gull* (-62%)

Roseate Tern (-90%)

Black Guillemot**

1970 to 20001987 to 2000

Figure 6.1 Percentage change in the number of seabirds counted in Scotlandduring c. 1970-2000 and c. 1987-2000. Figures in bracketsshow the percentage change during c. 1970-2000.Source: Mitchell et al. (2004).

Atlantic puffin (Fratercula arctica).L. Campbell

* Change based on coastal colonies only.**A comparable count of black guillemot (Cepphus grylle) was not undertaken during 1969-70,

so no change estimate is available for this species during c. 1970-2000.

34 3543

(Sterna hirundo). Scottish counts from all threecensuses are listed in Table 6.1. Although thefollowing figures describe changes in seabirdabundance throughout Scotland, it should benoted that trends sometimes vary markedlybetween Scottish regions, for example betweenpopulations in the North Sea and IrishSea/Atlantic Ocean.

Between the 1970 and 2000 censuses, 10 out of20 species (50%) showed a marked increase intheir Scottish breeding population (i.e. by at least10%), while six species (30%) showed a markeddecline (Figure 6.1). The proportion of speciesshowing gains or losses has changed considerablyover the c. 30-year period, however. During thefirst half of the period (c. 1970-1987) 60% ofspecies showed a marked increase, while 20%showed a marked decline. Equivalent figures forthe same species during the second half of theperiod (c. 1987-2000) were 40% and 50%,respectively.

Over the 30-year period, the greatest increasesshown were those of great skua, Arctic skua andcommon guillemot (Uria aalge), all of which morethan doubled their Scottish populations.Conversely, populations of two gull and two ternspecies fell by more than half, the most extremedecline being that of roseate tern (Sterna dougallii)(-90%), a Biodiversity Action Plan priorityspecies. While roseate tern numbers declined inboth halves of the 30 year period (1970-87 and1987-2000), some species have exhibited areversal in their population trend. Of 12 speciesshowing a marked population increase during thefirst half of the period, six have continued toincrease, while five have shown a marked decline.In percentage terms, the greatest of thesereversals was that of Arctic skua, whosepopulation increased by 226% during 1970-87

YEAR

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

* * * † *

CH

ICKS

FLE

DG

ED P

ER B

REED

ING

PA

IR

Figure 6.2 Variation in the meannumber of Arctic ternchicks fledged perbreeding pair, at asample of colonies inShetland. Source: Annual jointreports of JNCC, RSPBand Shetland OilTerminal EnvironmentalAdvisory Group, onseabird numbers andbreeding success inBritain and Ireland). *< 0.01. †< 0.02.

i Not fully surveyed in1998-2002.Extrapolated estimates for1999.ii Figures for thesespecies in 1969-70 and1985-88 were forcoastal colonies only. In1998-2002, inland aswell as coastal colonieswere counted, and areincluded in the totals forthat census. Forcomparison, figures fromcoastal colonies are alsogiven (in brackets) for the1998-2002 census. iii Figures refer toindividuals, not pairs.

Source: JNCC

Table 6.1The number of seabirds counted in Scotland during eachnational census: Operation Seafarer (1969-70), TheSeabird Colony Register (1985-88), and Seabird 2000(1998-2002) (from Mitchell et al., 2004). Figures indicatethe number of pairs, except where indicated.

Speciesnorthern fulmarManx shearwaterEuropean storm-petrelLeach’s storm-petrelnorthern ganneti

great cormorantEuropean shagarctic skuagreat skuablack-headed gullii

mew gullii

lesser black-backed gullii

herring gullii

great black-backed gullii

black-legged kittiwakeSandwich ternroseate terncommon ternArctic ternlittle terncommon guillemotiii

razorbilliii

black guillemotiii

Atlantic puffin

Fulmarus glacialisPuffinus puffinusHydrobates pelagicusOceanodroma leucorhoaMorus bassanusPhalacrocorax carboP. aristotelisStercorarius parasiticusCatharacta skuaLarus ridibundusL. canusL. fuscusL. argentatusL. marinusRissa tridactylaSterna sandvicensisS. dougalliiS. hirundoS. paradisaeaS. albifronsUria aalgeAlca tordaCepphus grylleFratercula arctica

1969-70285,067

---

96,8603,438

27,0771,0393,079

18,22612,22912,031

159,23715,950

346,0972,465

1344,285

46,385308

519,461111,038

-410,011

1985-88504,640

---

127,8672,986

31,5603,3887,6459,554

15,13419,52492,95015,315

359,4252,286

186,784

71,178373

943,098123,586

37,172438,101

485,852126,545

21,37048,047

187,3633,626

21,4872,1369,634

43,19148,11325,05772,13014,776

282,2131,068

144,784

47,306331

1,167,841139,186

37,505493,042

(6,888)(20,467)(21,565)(71,659)(14,773)

1998-2002


but dropped by 37% in 1987-2000. Of fourspecies showing a marked decline during the firsthalf of the period, three (black-headed gull,herring gull (L. argentatus) and roseate tern) havecontinued to decline. Only the great cormoranthas reversed this trend.

Breeding populations of great skua and Arcticskua in Britain and Ireland are virtually confinedto northern Scotland, where each has more thandoubled in size since 1970 (Figure 6.1). But whilegreat skua numbers continued to rise during1987-2000 (by 26%), the Arctic skua populationdeclined (by 37%) due, in part, to increasedpredation and competition from great skuas. Thismay have arisen as a result of a reduction in thevolume of fishing discards available to greatskuas, which have increasingly turned to preyingon Arctic skua chicks, and on other seabirdspecies. The latter include black-legged kittiwakes(Rissa tridactyla), which Arctic skuas parasitise.

Common guillemot, by far the most abundantseabird species in Scotland, has shown asustained rise between the three censuses,increasing by 82% during 1970-87, and by afurther 24% during 1987-2000. Two other aukspecies, razorbill (Alca torda) and Atlantic puffin(Fratercula arctica), have shown more modest gainsduring each half of the period, resulting inincreases of 25% and 20%, respectively, over1970-2000. Counts of the least abundant aukspecies, the black guillemot, have changed littlesince a survey conducted in 1982-91 (+1%).Numbers in the Northern Isles, the core of itsUK range, increased by 14%, despite heavymortality caused by the Braer oil spill (see Box10.1) in 1993 (Mitchell et al., 2004).

The northern gannet has shown a strongrecovery from historical persecution, populationestimates having increased by 32% during 1970-87 and by 47% during 1987-2000, yielding anincrease of 93% over the whole period. Northernfulmar numbers have also increased strongly overthe 30-year period (+70%), despite a slightdecline (-4%) during 1987-2000, particularly inthe more densely populated areas in northernScotland. No trend data are available for threeother petrel species (Manx shearwater, Europeanstorm-petrel and Leach’s storm-petrel), for whichrobust estimates were made for the first time in1998-2002. Of around 48,000 pairs of Leach’sstorm-petrel counted in Britain and Ireland, 94%were found in just four small islands in the StKilda archipelago (Mitchell et al., 2004).

Two gull species, lesser black-backed gull andmew (common) gull, also showed strongincreases within coastal colonies, of 79% and67%, respectively. The bulk of the mew gull’sScottish population breeds inland, however, asdoes the black-headed gull, whose coastalpopulation fell by 62% over the 30-year period.National counts of inland colonies of thesespecies, undertaken for the first time during1998-2002, will provide a more comprehensivebaseline for future surveys.

Two other gull species have shown markeddeclines. The herring gull population in Scotlanddeclined by over 50% during the 30-year period,coinciding with a general decline in commercialfishing, coupled with changes in fishing practices,both of which have contributed towards areduction in the volume of discards. Black-leggedkittiwake numbers have also shown a net declineduring 1970-2000 (-18%), though relatively stableduring the first half of this period. Althoughkittiwakes are still one of the most abundantseabirds, their breeding success in recent years

Left: Roseate tern (Sterna dougallii) C.Gomersall

Far left: Northern gannet (Morusbassanus)L. Campbell


Box 6.1 Ground predators

Disturbance and predation by foxes (Vulpesvulpes), stoats (Mustela erminea) and Americanmink (Mustela vison) have caused marked, localdeclines in the breeding populations of someseabird species in the UK (Lloyd et al., 1991).Other introduced species, including rats (Rattussp.), feral cats (Felis cattus) and ferret (Mustelafuro), also pose a threat to seabirds nesting onislands otherwise free from ground predators.Those at risk include hole-nesting species, such asAtlantic puffin (Fratercula arctica), Manxshearwater (Puffinus puffinus), European storm-petrel (Hydrobates pelagicus) and Leach’s storm-petrel (Oceanodroma leucorhoa), as well asground-nesting terns (Sterna spp.) and gulls (Larusspp.) and the black guillemot (Cepphus grylle),which nests in rock crevices.

Manx shearwaters have a lengthy breedingseason, making them particularly vulnerable toground predators. Predation by rats has reducedthe breeding success of Manx shearwaters onCanna, and has led to the abandonment ofseveral colonies around the British coast (Lloyd etal., 1991). Rats are also suspected or have beenproved to have affected colonies of roseate tern(Sterna dougallii), black guillemot and Atlanticpuffin (Lloyd et al., 1991).

A study of American mink predation on seabirdson the west coast of Scotland found evidence ofextensive predation at most gull and tern colonies(Craik, 1995). Although relatively few adultswere killed by mink, no or very few fledgedyoung were produced from colonies where minkwere uncontrolled. The high impact of mink wasattributed to their population density andpropensity for surplus killing; in Iceland, one minkden was found to contain 200 guillemot chicks (T.Björnsson in Clode and MacDonald, 2002). Themink’s impact is also due in part to its ability toswim to islands more than 2 km from themainland (Craik, 1995) or, by ‘island hopping’,up to 10 km offshore (Clode and MacDonald,2002). After one or more years of breedingfailure, most of the areas colonised by mink onthe west coast of Scotland held no birds, or onlygreatly reduced numbers (Craik, 1997). During1989–1996, the impact of mink predation onbreeding success and adult dispersal was thoughtto have been the main cause of a 52% decline inthe breeding population of black-headed gull(Larus ridibundus) and a 30% decline in mew gull(Larus canus) numbers (Craik, 1997).

Right: Manxshearwater (Puffinuspuffinus).L. Gill/SNH

has been poor, as a result of low sandeelavailability in the North Sea, particularly aroundShetland. In contrast, great black-backed gull(Larus marinus) numbers have shown little change,declining by only 7% over the 30-year period,despite competing to some degree with theincreasing great skua population (Mitchell et al.,2004).

Three tern species have shown modest netchanges, but contrasting trends, over the 30-yearperiod. An initial 58% increase in common ternnumbers during 1970-1987 was followed by a29% decline, yielding a net increase of 12% overthe whole period. Arctic tern (Sterna paradisaea)and little tern (S. albifrons) numbers showedsimilar, strong increases initially, of 53% and21%, followed by declines of 34% and 11%. In1980 about 85% of the British and Irishpopulation of the Arctic tern bred in theNorthern Isles, but by 1989 their numbers inOrkney and Shetland had fallen by 42% and 55%

respectively (Avery et al., 1993). In Shetland, thesedeclines coincided with very low breedingsuccess, associated with a lack of sandeel prey(Figure 6.2). Fluctuations in sandeel availabilityare occasionally associated with catastrophicbreeding failures, as occurred there in 1998, when4,020 pairs fledged just 45 young (Thompson etal., 1999). Declines in the little tern populationhave been attributed, in part, to egg and chicklosses to foxes (Vulpes vulpes), kestrels (Falco

tinnunculus) and other predators (Mitchell et al.,2004).

The Sandwich tern (Sterna sandvicensis) populationin Scotland has shown a sustained declineamounting to 57% over the whole period. Thecauses of this decline are difficult to discern, buthave been linked to persecution on the species’wintering grounds in NW Africa. Persecution isalso thought to have contributed to the decline ofthe roseate tern which, having decreased by 67%in Britain and Ireland (by 90% in Scotland)


during 1970-2000, is Britain’s rarest breeding tern.The dramatic decline in the population inScotland has been attributed to emigration (toIreland), as well as to persecution in its winteringgrounds. While the decline in its Scottish and UKpopulation continued during 1997-2000, itscombined British and Irish population has shownsome signs of recovery, increasing by 44%(Mitchell et al., 2004).

The great cormorant population declined by 13%during 1970-1987 but then increased by 21%, togive a net increase of 5% over the whole period.In contrast, European shag (Phalacrocorax

aristotelis) numbers showed an initial increase(+17%; 1970-1987) followed by a decline (-32%;1987-2000), resulting in a net reduction innumbers (-21%) over the whole period. InShetland, which held about 20% of the Scottishpopulation in 1985-88, numbers fell by more than50% between 1986 and 1999. Populations on theeast coast of Scotland also showed a dramaticdrop in numbers following the winter of1993/94.

Issues and implicationsThe main factors influencing population trends inScotland’s seabirds are as follows.

● Food availability. This has a major influenceon breeding performance, and is in turnaffected by commercial fisheries and climaticfluctuations. Two-thirds of seabirds in theNorth Sea in summer are thought to feed tosome extent on fishery waste, and theabundance of commercial fishing discardshas been linked to population change insome species. Commercial fisheries,particularly for sandeels, can also have asubstantial, negative impact on foodavailability.

● Predation. Rats, feral cats, ferret (Mustela furo)

and American mink (M. vison) can have asevere impact on breeding and adult survival(Box 6.1).

● Drowning. Nets, particular monofilament driftnets, were considered the main cause ofunnatural deaths among auks in the 1980s.

● Pollution. Chronic oil pollution from illegaldischarges has had a greater impact thanoccasional accidental spills. Pesticide residuesand other toxic chemicals have beenimplicated in population crashes.

● Culling. Now controlled through legislation,egg collection, and the hunting for food,

feathers and sport has historically had amajor impact on populations.

Sources of dataPublished data from the three national censuses,conducted in 1969-70, 1985-88 and 1998-2002,are augmented by annual surveys within a sampleof seabird colonies (e.g. Mavor et al., 2003),providing an indication of regional trends inpopulation size and breeding success.

This chapter is based mainly on informationpresented in Lloyd et al. (1991) and Mitchell et al.(2004). The latter describes the most recentcensus, Seabird 2000, a collaborative projectinvolving the Joint Nature ConservationCommittee, the UK Government’s conservationagencies, the Royal Society for the Protection ofBirds, the Seabird Group, Shetland Oil TerminalEnvironmental Advisory Group (SOTEAG),BirdWatch Ireland and the National Parks andWildlife Service (Dept. of Environment, Heritageand Local Government - Republic of Ireland).

ReferencesAvery, M.I., Burges, D., Dymond, N.J., Mellor, M.and Ellis, P.M. (1993). The status of Arctic TernsSterna paradisaea in Orkney and Shetland in1989. Seabird 15: 17-23.

Clode, D. and MacDonald, D.W. (2002). Invasivepredators and the conservation of island birds: thecase of American Mink Mustela vison and ternsSterna spp. in the Western Isles, Scotland. BirdStudy 49: 118-123.

Craik, C. (1995). Effects of North American minkon the breeding success of terns and smaller gullsin west Scotland. Seabird 17: 3-11.

Craik, C. (1997). Long-term effects of NorthAmerican Mink Mustela vison on seabirds inwestern Scotland. Bird Study 44: 303-309.

Lloyd, C., Tasker, M.L. and Partridge, K. (1991).The Status of Seabirds in Britain and Ireland. T. &A.D. Poyser, London.

Mavor, R.A., Parsons, M., Heubeck, M., PickerellG. and Schmitt, S. (2003). Seabird Numbers andBreeding Success in Britain and Ireland, 2002.Joint Nature Conservation Committee,Peterborough.

Mitchell, I.P., Newton, S.F., Ratcliffe, N. and Dunn,T.E. (2004). Seabird populations of Britain andIreland. T. and A.D. Poyser, London.

Thompson, K.R., Pickerell, G. and Heubeck, M.(1999). Seabird Numbers and Breeding Success inBritain and Ireland, 1998. Joint NatureConservation Committee, Peterborough.

The use of the seaPart 3


Mariculture7

IntroductionClean waters and a widespread availability ofwave-sheltered sites have made Scotland aparticularly attractive location for the farming ofboth finfish and shellfish (mariculture).Commercial salmon farming began in Scotland in1969 with the establishment of the first farmsnear Aberdeen on the east coast and at LochAilort, south of Mallaig, on the west coast.Modern shellfish culture became establishedaround the mid-1980s. At the outset, the industrywas hailed as environmentally sympathetic:potentially providing relief for the heavilyexploited wild fish stocks while producing ahealthy, high-value product raised within itsnatural environment. Few predicted the scale ofsuccess of the industry in Scotland and itseventual dominance of the economy of thewestern, north-western and island coastalcommunities.

TrendsIn 1979, just over 1,000 tonnes of wild Atlanticsalmon (Salmo salar) was available for market, butonly 510 tonnes of farmed fish was produced(Anon., 2000). Growth in production was slowuntil the mid-1980s, when financial incentivesstimulated a major expansion of the industry(Figure 7.1).

In 2002, over 145,000 tonnes of farmed salmonwas produced by a total of 328 marine farm sites(Figure 7.2) around Scotland (Fisheries ResearchServices, 2003a).

A number of sites and companies are annuallyregistered as non-producing. Although notyielding a harvest for market, they may be activelygrowing stock that will constitute the followingyears’ product. A large drop in the number ofproducing sites between 1999 and 2000 reflects aprogramme of slaughter and site fallowing. Thiswas largely initiated as part of the restrictionsthat followed the west-coast outbreak of thecontagious viral disease infectious salmonanaemia (ISA) in 1998.

The number of salmon farm-related businessespeaked at 176 in 1989 and then declined, partly asa result of a series of mergers and buy-outs(Figure 7.2). The level of employment and thetotal number of production sites have, however,remained largely stable throughout the 1990s tothe present (Figure 7.3). Advances in productionmethods and the use of modern technology inthe design and manufacture of holding cageshave led to improving yields and higherproductivity (Figure 7.4).

Experimental farming of other fin fish species,such as cod (Gadus morhua), turbot (Scophthalmus

maximus), sea trout (Salmo trutta) and Arctic char(Salvelinus alpinus), is currently under way.

Shellfish production is low in Scotland comparedwith other European countries and is consideredto be less environmentally damaging. The mainspecies are mussels (Mytilus edulis), Pacific oyster(Crassostrea gigas), scallop (Pecten maximus) andqueen scallop (Aequipecten opercularis), with

Previous page: Creels.D. Donnan

Right: Salmon farm,Shetland.G. Saunders

Right: Mussel farm, LochStriven.C. Adams


0

30000

60000

90000

120000

150000

200219991996199319901987198419811979

YEAR

PRO

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ON

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ES)

0

50

100

150

200

250

300

350

400

Number of businesses producingTotal number of businesses

Number of sites producingTotal number of fish farm sites

20021999199619931990198719841981

YEAR

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BUSI

NES

SES/

SALM

ON

PRO

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ON

SIT

ES

0

200

400

600

800

1000

1200

Full-time employed Part-time employed

20021999199619931990198719841981

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NO

. OF

EMPL

OYE

ES

0

20

40

60

80

100

120

20021999199619931990198719841981

YEAR

TON

NES

PER

PER

SON

Mussel (tonnes)Scallop (000s)

Native Oyster (000s)

Queen Scallop (000s)Pacific Oyster (000s

0

500

1000

1500

2000

2500

3000

3500

4000

200220001998199619941992199019881986

YEAR

PRO

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production concentrated on the west coast,particularly in Argyll. Production of shellfish hasalso grown, but on a much smaller scale, rising to3,236 tonnes of mussels and 3,114,000 individualPacific oysters (the main species) in 2002 (Figure7.5).

Issues and implicationsCurrently, almost all sea lochs with conditionssuitable for mariculture have at least oneinstallation, prompting concerns about localisedimpacts on the sea bed, aesthetic degradation ofthe landscape, nutrient enrichment of coastalwaters and interactions with wild populations.Salmon farming in particular has attractedcriticism, with concerns over disease outbreaksand interactions with wild salmon populations(Baxter and Hutchinson, 2002).

High stocking densities have increasedsusceptibility to disease outbreaks. Heavy lossesof salmon occurred in 1990–1991 due to sea liceand the bacterial disease furunculosis. Vaccinesand therapeutic chemicals are now used routinelyto keep stock losses to a minimum. In May 1998

Figure 7.1 Total annual Scottish production of farmed salmonSource: Fisheries Research Services, 2003a.

Figure 7.5 Scottish shellfish production for the tableSource: Fisheries Research Services, 2003b.

Figure 7.4 Scottish salmon farm productivity Source: Fisheries Research Services, 2003a.

Figure 7.3 The number of people employed in the salmon farm industry Source: Fisheries Research Services, 2003a.

Figure 7.2 The number of Scottish marine salmon production sites and salmonproduction businesses operating in ScotlandSource: Fisheries Research Services, 2003a.


an outbreak of ISA was confirmed in Scotland,and by August 1999 there had been 11 confirmedcases (Table 7.1), with a further 24 suspected(Fisheries Research Services, 2000). This disease,thought to be relatively benign in other speciessuch as trout (Salmo trutta), was first recorded inNorway in 1984 and more recently in Canada in1996. It is likely that ISA was introduced toScotland through a slackening of hygiene andhusbandry methods precipitated by the success ofthe furunculosis vaccine (Smith, 1999).Subsequent control measures and a maintainedobservance of improved working practices haveprevented a recurrence.

In many cases, the sea bed beneath salmon cagesis contaminated with uneaten food and faecalmaterial, together with pharmaceuticals,pesticides and chemical antifoulants applied tothe cage structure. Contamination may persist foras much as two years after the removal of cages(Pearson and Black, 2001). Good flushingregimes in site selection can help to dispersecontaminants and so alleviate the problem oflocal accumulation.

The siting of new mariculture installations inScotland is now the subject of consultationinvolving the Scottish Environment ProtectionAgency (SEPA) and SNH. The potential fordamage to the environment is examined case bycase, and advice is given using the best availableinformation. Fish farms are granted dischargeconsents by SEPA, which may limit annualproduction and the quantities of chemicals thatmay be used. With vigilance encouraged by self-monitoring, together with revocation of consentsif specified practices are not followed, recentimprovements in benthic sediment quality aroundsome marine cage fish farms have beendocumented.

Shellfish production relies on naturalphytoplankton in the water as the food source.

Region No. of confirmed casesShetland 2Loch Nevis 3Skye 1Sound of Mull 5

Table 7.1 The number of confirmed cases of ISA by region. Source: Scottish Parliament, 1999

Oyster farm, Loch Kishorn. D.Donnan


Some of the planktonic species that constitutefood for shellfish produce toxins that aresubsequently concentrated within the shellfish.Consumption of shellfish containing these toxinsmay cause paralytic shellfish poisoning (PSP),amnesic shellfish poisoning (ASP) or diarrheticshellfish poisoning (DSP), all of which arecharacterised by headaches, nausea, diarrhoea andrespiratory paralysis.

Monitoring shellfish (both wild-caught andfarmed) for the toxins responsible for PSP beganafter an outbreak in 1968 resulted in thehospitalisation of several people in north-eastEngland and south-east Scotland. Theprogramme was extended in 1999 to include ASP.Many of the shellfish production sites wereclosed during 2000 because of the presence oftoxins. Concern has been expressed that nutrientsreleased from salmon farms may be related to anincrease in the frequency of toxic algal blooms.Further long-term monitoring is needed toestablish if blooms of toxic algae are increasingin reality, or merely appear to be as a result of thegreater intensity of monitoring. Other possiblecauses, such as climate change, natural variabilityand the effects of fisheries, pollution and globaltransfers of harmful species, may also beimplicated and require further investigation.

Recent modelling data for dissolved inorganicnitrogen in Scottish lochs (Gillibrand and Turrell,1997) suggest that a few fish farms may createminor localised enrichment relative to naturallevels, but that mariculture-derived inputs remaincomparatively low when viewed alongside othersources (Davies, 2001). A direct connectionbetween mariculture and an increase in theoccurrence of harmful algal blooms cannottherefore be reliably demonstrated, and suchincreases must be considered within the contextof observed long-term natural changes in theAtlantic phytoplankton.

Sources of dataDetailed reports for both shellfish and finfishproduction are published annually by theFisheries Research Services (the MarineLaboratory, Aberdeen).

ReferencesAnon. (2000). Scottish fish farming: past andpresent. Aquaculture Magazine 26, March/April2000, 48–54.

Baxter, J. and Hutchinson, P. (2002). The Atlanticsalmon: a case study of Scotland’s environmentand natural heritage. In: The State of Scotland’sEnvironment and Natural Heritage. Usher, M. B.,Mackey, E. C. and Curran, J. C. (eds), pp.219–234. The Stationery Office, Edinburgh.

Davies, I. M. (2001). Waste Production byFarmed Atlantic Salmon (Salmo salar) in Scotland.International Council for the Exploration of theSea, CM 2000/O :01 Sustainable AquacultureDevelopment.

Fisheries Research Services. (2000). Final Reportof the Joint Government/Industry Working Groupon Infectious Salmon Anaemia (ISA). ScottishExecutive, Aberdeen.

Fisheries Research Services. (2003a). ScottishFish Farms. Annual Production Survey, 2002.Scottish Executive Rural Affairs Department.

Fisheries Research Services. (2003b). ScottishShellfish Farm Production Survey, 2002. ScottishExecutive Rural Affairs Department.

Gillibrand, P. A. and Turrell, W. R. (1997). Theuse of simple models in the regulation of theimpact of fish farms on water quality in Scottishsea lochs. Aquaculture 159: 33–46.

Pearson, T. H. and Black, K. D. (2001). Theenvironmental impacts of marine fish cage culture.In: Environmental Impacts of Aquaculture. Black,K. D. (ed.), pp. 1–31. Sheffield Academic Press,Sheffield.

Scottish Parliament. (1999). Salmon Farming andthe Impacts of ISA. Scottish Parliament ResearchNote No. 99/20. Scottish Parliament, Edinburgh.

Smith, P. D. (1999). Fish and Shellfish Cultivationand Health Review for the Ministry of Agriculture,Fisheries and Food.


Continental shelf fisheries8

IntroductionThe scale of marine capture fisheries, bothgeographically and quantitatively, represents oneof the greatest human-induced modifications ofmaritime ecosystems. It is estimated that globallyover 80 million tonnes (including shellfish) waslanded in 1999 (FAO, 2000). More than a quarterof world fish stocks are considered to be eitheroverfished or in imminent danger of stockcollapse.

Over 1,000 species of fish have been recorded inthe north-eastern Atlantic and North Sea region.Of these, about 5% are considered to becommercially exploitable. Around 20 speciesconstitute approximately 95% of total fishbiomass.

In the North Sea, about a fifth of the estimatedtotal of 10 million tonnes (mt) of fish are landedannually. This, of course, excludes discarded fish.The 2002 landings (ICES, 2003) of 2,125 mtcomprised 337 mt of demersal species, 892 mt ofpelagic fish and 896 mt from the industrialsandeel fishery.

Finfish and shellfish have been harvested inScottish coastal waters for many centuries. Earlyexploitation probably developed out of necessity,since the greater part of the country – especiallythe hill and mountain areas – is of limitedproductivity. Over several centuries theavailability of this abundant and relatively reliablefood source was a major factor in the settlementof the greater proportion of the population incoastal areas (Coull, 1996).

During medieval times the catching andprocessing of fish, notably herring (Clupea

harengus), became an important feature ofScottish culture and trade (Cushing, 1988), andthe commercial exploitation of fish and shellfishstocks remains a major contributor to Scotland’seconomy today. In 2001, total live weight landingsof fish and shellfish by UK vessels into Scotlandamounted to 307,700 tonnes valued at £247.1million (Scottish Executive, 2002). AlthoughEngland, Wales and Northern Ireland maintain afishing fleet, Scotland remains at the centre ofUK fishing activity, with 65% of all UK landingsmade in Scottish ports (Scottish Executive, 2002).

Pelagic trawler haulingnets.C. Martin/SNH


The fishing industry comprises three mainsectors:

● Demersal species such as cod, haddock,whiting and flatfishes mainly live close to thesea bed. They are caught principally withtrawls, but static gill and tangle nets may alsobe used. Demersal fish have historicallyattracted a greater value per unit weight andhave been preferentially harvested. Over-exploitation has resulted in a steady decline indemersal fish landings, with a decrease ofgreater than 10% for 16 of the 34commercially important species between1995 and 1999.

● Pelagic species such as herring or mackerelmay range over considerable depths but arecaught either close to the surface or in mid-water using seine nets or pelagic trawls.Catches of pelagic fish have generallyincreased since the 1960s, coincident with adecline in demersal populations.

● Shellfish traditionally includes species that haveeither a hard shell, such as scallops, cockles,mussels, winkles and buckies (whelks), or anexoskeleton, such as edible crabs, velvetcrabs, crayfish, lobster and Norway lobster.Shellfish are caught using trawls, baited creelsor pots and occasionally bottom-set nets.

Box 8.1 Stock assessmentIn order to evaluate stock status four maincharacteristics of exploited populations areexamined on an annual basis:

● Landing: the total annual reported tonnageof fish removed from the stock and landedby the fishing fleet.

● Spawning stock levels: measured asspawning stock biomass, which is the totalestimated weight of fish that are matureenough to be able to spawn.

● Fishing mortality: an index of the totalnumber of fish that are removed from aparticular stock each year by fishingactivities (a fishing mortality of 1.0corresponds to a 60–70% reduction in stockover the course of one year).

● Recruitment: the number of young fishproduced each year that survive to becomeadults and enter the fishery.

TrendsStock assessment is based on landings, spawningstock, fishing mortality and recruitment (Box8.1). Scottish data are available for 16 species,shown in Table 8.1.

In recent times, many marine capture fisheriesthroughout the world have entered a state ofcrisis, with many stocks severely depleted orexploited to the brink of collapse.

The number of people employed in the Scottishfishing industry declined by almost 30% between1992 and 2002 (Scottish Executive, 2002), largelydue to an inability to sustain catch levels andattempts to limit catches of stocks that hadbecome dangerously depleted. In 2002, theScottish fleet employed approximately 5,707people working on a total of 2,513 vessels.

None of the species commercially exploitedwithin Scottish waters is currently considered tobe in danger of global biological extinction, asthey often have a wide geographical range withestablished populations thousands of kilometresapart. However, many species maintaingenetically discrete stocks, differentiated by theareas in which they spawn, develop and feed.Several individual stocks are considered to beeither fully exploited or overexploited. Some havereached a point at which stock collapse isconsidered an imminent possibility. Conversely,stock recovery has been demonstrated throughfisheries management (Box 8.2).

Plaice (Pleuronectesplatessa).R.Holt

Herring shoal (Clupeaharengus).S. Scott

Edible crab (Cancerpagurus).G.Saunders


Table 8.1 Species trends for fisheries of greatest commercial importance (sources: ICES, 2001, 2002, 2003)

SpeciesHerring (Clupea harengus) (2003)

Cod (Gadus morhua) (2003)

Haddock (Melanogrammusaeglefinus) (2003)

Whiting (Merlangius merlangus)(2003)

Saithe (Pollachius virens)(2003)

Norway pout (Trisopterus esmarki) (2003)

Sandeel (Ammodytes marinus)(2003)

Stock assessment• Spawning stock level above the proposed

precautionary stock biomass level • Fishing mortality for North Sea stocks below the

proposed precautionary level and considered tobe low for west of Scotland stocks

• Recent recruitment has been strong in the NorthSea and 2001 produced a strong year class tothe west of Scotland

• Spawning stock levels below the proposedprecautionary stock biomass level. Spawningstock has been declining since 1980 and theestimate for 2002 is the lowest ever

• Fishing mortality is above the proposedprecautionary level and the absolute value isdifficult to determine owing to the suspectedincreased in unreported landings

• Recruitment has been poor in the last five yearsand in the North Sea the 1997, 2000 and2002 year classes are the poorest on record

• Spawning stock levels above the proposedprecautionary stock biomass level and boostedby the good recruitment of 1999

• Fishing mortality has been above the proposedprecautionary level but fell below this in 2002

• Recruitment in 1999 was very strong, but sincethen in the North Sea has been considered wellbelow average

• Spawning stock level below the proposedprecautionary stock biomass level

• Fishing mortality is above the proposedprecautionary level for west of Scotland stocks,but below it for the North Sea stocks

• Recruitment in both North Sea and west ofScotland stocks has been low since the early1990s. There are some indications that theNorth Sea stocks may have increased in recentyears

• Spawning stock level close to or above theproposed precautionary stock biomass level

• Fishing mortality is below the proposedprecautionary level

• Recruitment considered to be stable

• Spawning stock level currently above theproposed precautionary stock biomass level butexpected to decrease significantly

• Fishing mortality considered to be low and isless than natural mortality

• Recruitment is highly variable and is stronglyinfluenced by spawning stock owing to theshort lifespan of this species

• Spawning stock level is thought to have risenabove the proposed precautionary level in2003

• No indicators for fishing mortality have beenset

Stock healthNorth Sea stocks are considered to beinside safe biological limits

Currently considered to be outside safebiological limits with a high risk ofstock collapse

Currently considered to be inside safebiological limits (except in the IrishSea)

Currently considered to be outside safebiological limits

Data from the North Sea haveproduced conflicting trends for 2002,therefore the health of the stock in thisarea is unknown

Currently considered to be within safebiological limits

North Sea stocks are considered to bewithin safe biological limits. The statusof the west of Scotland stocks isuncertain

The status of stocks in the North Sea isuncertain. The status of the west ofScotland stocks is unknown.

Year in brackets indicates the most recent assessment data available.Stocks with are outside safe biological limits are indicated by blue shading.


Stock health


Currently considered to be outside safebiological limits. North Sea stockcomponent considered to be severelydepleted

A high and stable catch biomass isthought to indicate a healthy NorthSea stock level


There is not enough informationavailable on the stocks to the west ofScotland to determine their status

Currently considered to be outside safebiological limits in the North Sea andwithin safe biological limits in the IrishSea


Status of stocks variable, although moststocks are considered to be fullyexploited.

The current state of the North Seastock is unknown

Stock assessment• Recruitment in the 2001 year class is still strong

although the 2002 year class was poor

• Spawning stock biomass has decreasedalthough no biomass reference points havebeen identified for this stock.

• Recent fishing mortality is well above theproposed precautionary level

• No data available on recruitment, although thefishery is thought to be taking a proportion ofjuveniles, which are removed from the fisheryseveral years before they become mature

• Spawning stock level above the proposedprecautionary stock biomass level

• Fishing mortality is above the proposedprecautionary level

• Recruitment appears stable

• There are no data available for spawning stocklevel, fishing mortality or recruitment

• Biomass appears to have increased in recentyears; however, there is a relatively lowabundance of older year classes. There arealso indications of a strong recruitment in 2003

• Spawning stock level below the proposedprecautionary stock biomass level Fishing mortality has remained above theproposed precautionary level since 1978

• Recruitment levels between 1997 and 2001were the lowest recorded. There was, however,a slight increase in 2002

• Reliable estimates for spawning stock level,fishing mortality and recruitment are notavailable

• Spawning stocks levels in the North Sea areclose to the historical minimum. Stocks in theIrish Sea appear healthy

• Fishing mortality is above the proposedprecautionary level in the North Sea, but belowit in the Irish Sea

• Recruitment in the North Sea has been belowaverage since a good year class in 1996

• Spawning stock level is below the proposedprecautionary stock biomass level

• Fishing mortality is above the proposedprecautionary level

• Recent recruitment at or above average in theNorth Sea. The 2001 recruitment in the IrishSea is the poorest on record.

• Catch rates suggest that current levels of fishingare acceptable

• Recruitment largely stable

• There are no data available for spawning stocklevel, fishing mortality or recruitment; total effortis thought to have been low since 1999

Species

Monkfish (Lophius piscatorius) (2003)

Mackerel (Scomber scombrus) (2003)

Sprat (Sprattus sprattus) (2003)

Hake (Merluccius merluccius)(2003)

Megrim (Lepidorhombus whiffiagonis) (2003)

Plaice (Pleuronectes platessa)(2003)

Sole (Solea solea) (2003)

Norway lobster (Nephrops norvegicus)(2003)

Northern shrimp (Pandalus borealis) (2003)

Year in brackets indicates the most recent assessment data available.Stocks with are outside safe biological limits are indicated by blue shading.


Box 8.2 Herring stocks

The Scottish herring fishery has a verylong history, with records of tradingextending back to at least the12th century.Today, herring continues to be animportant catch for Scottish fishermen, witha value of over £6 million of landings toScottish ports in 2002. By weight, herringis the second most abundant species, aftermackerel, landed by the pelagic fleet, withthe major fishing effort being concentratedaround Shetland and to the north and westof Scotland. They are caught either bypurse seine or by pelagic trawl.

North Sea stocks declined drasticallybetween the early 1960s and 1976(Figure 8.1), largely as a result of the

combined effects of poor survival of youngherring and overfishing of adults andimmature fish on their nursery grounds. Aban on fishing for herring between 1977and 1981 allowed stocks to recover (smalllandings during that time were probablydue to bycatch from other fisheries andscientific survey). By 1996, however,exploitation levels in the North Sea hadagain increased to a such an extent thatmeasures had to be reintroduced to reducefishing mortality (ICES, 2001).

Currently, North Sea herring stocks areconsidered to be inside safe biologicallimits following a gradual recovery.Information has been insufficient to fullyassess populations exploited to the west ofScotland, but reports suggest that stocks

remain stable and fishing mortality maybe decreasing, perhaps because of apoor market for herring compared withother pelagic fish.

● Of the 16 species for which Scottish data areavailable, seven are currently considered to beoutside safe biological limits (Table 8.1). Codhave attracted particular concern (Box 8.3).

● In the 10-year period between 1992 and 2002,spawning stock biomass of some stocks ofcod, whiting, plaice and sole declinedsubstantially (Table 8.2). Conversely, thespawning stock biomass of herring, haddock,saithe and mackerel increased.

● Landings of the majority of species havedeclined (Table 8.2), either because ofimposed catch restrictions or because of an

inability to locate adequate supplies.

● Depletion of stocks of traditionally fishedspecies has stimulated the targeting ofpreviously unexploited species, such asmonkfish and a number of species only foundin the deeper, offshore grounds (Chapter 9).

The harvesting of shellfish has increasedconsiderably in recent times. Between 1984 and1997, the total UK shellfish catch more thandoubled to over 142,000 tonnes. Landings of 5 ofthe 10 most commercially important species inScotland increased by more than 10% between1995 and 1999.

0

200

400

600

800

1000

1200

1400

20031999199519911987198319791975197119671963

YEAR

CAT

CH

(000

s TO

NN

ES)

a.

0

500

1000

1500

2000

2500

200319991995199119871983197919751971196719631959

YEAR

BIO

MA

SS (0

00s

TON

NES

)

d.

0.0

0.3

0.6

0.9

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200319991995199119871983197919751971196719631959

YEAR

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c.

0

20000

40000

60000

80000

100000

120000

200319991995199119871983197919751971196719631959

YEAR

REC

RUIT

MEN

T (M

ILLI

ON

S)

b.

Figure 8.1Changes in (a)catch, (b) recruitment(age 0), (c)fishing mortality(age 2–6) (d) spawningstock biomass forNorth Seaherring.

Above: Herring (Clupea harengus).C.Gomersall


Box 8.3 Cod stocks

By 1999 the status of cod stocks from all UKsectors was giving cause for concern. Fishingmortality had increased steadily since the 1960s(Figure 8.2).

Spawning stock biomass of North Sea stocks hadbeen declining since the early 1970s, and wasfollowed by west of Scotland populations in the1980s (Figure 8.3). Some stocks fell belowestimated precautionary levels in 1984 andcontinued to decline thereafter. Recruitment,although variable, was consistently poor in the1990s, with the 1997 North Sea year classbeing the poorest on record. By 1999, all codstocks within UK waters were considered to beoutside safe biological limits. Continuedexploitation at current levels is thought likely torisk imminent stock collapse. Data from 2002show an increase in the spawning stock biomassof cod in the North Sea. It is suspected that this isas a result of growth of individuals in the currentpopulation rather than an increase in numbers offish present. The spawning stock biomass data for2003 are considered uncertain.

Increasing pressure has been exerted on codpopulations by the removal of young fish. By thetime they reach their second year, the stillimmature cod are fully exploited, and many willnot reach maturity. As little as 0.05% of all one-year-old fish survive to reach their fourth year.Although fishing mortality has increased across allage groups, the two- and three-year age groupshave been removed at disproportionately greaterrates (Figure 8.4).

Moreover, the growth rate of North Sea cod hasdeclined for reasons which are not clear. This,combined with high mortality of juvenile cod dueto discarding, is likely to delay a future recoveryof spawning stock biomass levels and leave stockshighly vulnerable to overexploitation.

0.0

0.5

1.0

1.5

2.0

20021998199419901986198219781974197019661962

YEAR

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IND

EX

North Sea

West of Scotland

Irish Sea

0.0

0.3

0.6

0.9

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1.5

20001995199019851980197519701965

YEAR

MO

RTA

LITY

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EX

Age 1

Age 2

Age 3

Age 4

0

50000

100000

150000

200000

250000

300000

20031963

YEAR

BIO

MA

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ON

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20000

25000

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40000

1998199319881983197819731968

BIO

MN

ASS

(TO

NN

ES) I

RISH

SEA

& W

EST

OF

SCO

TLA

ND

North Sea

West of Scotland

Irish Sea

Figure 8.2 Changes in cod fishing mortality.

Figure 8.4 Trends in fishing mortality of different age groups ofthe west of Scotland cod stock.

Figure 8.3 Changes in cod spawning stock biomass.

Cod (Gadus morhua).S. Scott


Issues and implicationsThe seas around Scotland have traditionally beenrich in commercially valuable species and havesupported some of the most intensive fishingeffort in the world. Detailed studies of UK andinternational fishing effort in the North Sea showthat grounds presently subjected to the greatestintensity of otter trawling lie to the north-east ofthe UK (Figure 8.5), largely comprising areas offthe east and north-east Scottish mainland andeast of the Shetland Islands (Greenstreet et al.,1999a; Jennings et al., 1999, 2000). The nature of

the fishery, as defined by the type of fishing gear,has changed within the last 30 years. The use ofdemersal gears, such as otter (Figure 8.6) andbeam trawls, targeting species such as cod (Gadus

morhua), haddock (Melanogrammus aeglefinus) andplaice (Pleuronectes platessa), has increased steadilythroughout the North Sea since the mid-1970s(Jennings et al., 1999), while the pursuit of pelagicspecies, predominantly mackerel (Scomber scombrus)and herring, with seine nets (Figure 8.7) hasdecreased (Greenstreet et al., 1999a).

Above: Figure 8.5 Spatial distribution ofinternational ottertrawling effort (hours) in1995. Reproduced fromJennings et al. (1999).

Above right: Figure 8.6

Typical otter trawl gearconfiguration

(Scottish Executive,Crown copyright).

Right:Figure 8.7

Purse seine gear (Scottish Executive,Crown copyright).


Species

Herring

Cod (1990–2000)

Cod

Haddock

Haddock

Whiting (1992–2000)

Whiting

Saithe

Norway pout

Mackerel

Plaice

Sole

Area of stockassessment

North Sea

North Sea

West of Scotland

North Sea

West of Scotland

North Sea

West of Scotland

North Sea and west ofScotlandNorth Sea

North-east Atlantic andNorth SeaNorth Sea

North Sea

Landings

42.5%�

44%�

77%�

24%�

41%�

62%�

72%�

17%�

74%�

7%�

44%�

42%�

Fishing mortality

46%�

7%�

2.6%�

65%�

23%�

51%�

13%�

66%�

43%�

2%�

1.4%�

12%�

Spawning stockbiomass

34%�

31%�

81%�

305%�

47%�

17%�

45%�

152%�

2%�

56%�

47%�

56%�

Catch quotas were first implemented in theNorth Sea in the mid-1970s. Exploited stocks inEuropean waters are now managed through theCommon Fisheries Policy (Box 8.4), acting jointlywith Norway in the case of shared stocks.

The ICES provides annual scientific advice onthe status of all of the important commercialspecies. Catch levels are subsequently decided bythe Council of Ministers, and catch quotas areduly allocated to member states. The primaryobjective is the maintenance of these resources ata level at which they can be harvested sustainably.The scale and ecological complexity of such anundertaking, combined with inevitable politicalpressures, have, however, proved to be majorobstacles and the maintenance of stablepopulation levels remains elusive.

Many demersal stocks, and notably cod (Box 8.3),have continued to decline despite successivereductions in catch quotas. This is probably areflection of fundamental differences in theselectivity of pelagic and demersal fishing gears.Pelagic species are typically targeted as mid-water

Table 8.2 Characteristics of important commercially exploited fish stocks: 10-year trend, 1992–2002 (except where indicated) Sources: ICES, 2001, 2002.

schools of high species uniformity and can beidentified visually or by a characteristic acousticsignature. Avoidance of a particular species as aconservation measure is thus relatively easy andeffective. Demersal trawling gears are far lessselective and, although controls on the landing ofa particular species may be in place, incidentalcapture of both adults and juveniles cannot beavoided without the closure of entire grounds(Hutchings, 2000).

Cod stocks from the North Sea, Irish Sea andwest of Scotland are reported to be in danger ofcollapse (ICES, 2001, 2002). Recovery plans wereinitiated during 2000, incorporating limited areaclosures and modifications to gears to increaseselectivity. Quotas were then cut by 45% in 2003and remained the same in 2004. Then, effortreduction was introduced, limiting days at sea to15 per month (increased from 10 days as a resultof fleet reduction through decommissioning). Aproposal was also announced to introducemultiannual management arrangements for codstocks in the North Sea, west of Scotland, IrishSea and eastern Channel. Along with this is a


Box 8.4 The Common Fisheries Policy

The European Common Fisheries Policy (CFP), which integrates the protection ofthe marine environment with fisheries management, was enacted in CouncilRegulation 3760/92 in 1992. This regulates the exploitation of commercialstocks through the specification of fishing quotas and, in some cases, thedesignation of marine areas within which fishing practices may be restricted.The CFP is enacted nationally through the Sea Fisheries (Wildlife Conservation)Act 1992 for the conservation of marine flora and fauna, requiring a balancingof duties between conservation and obligations under existing fisheries Acts.Several methods of reducing fishing effort have been made available under theSea Fish (Conservation) Act 1992, including limits on fishing days at sea,restrictions on certain types of fishing gear and grant-aided decommissioning.

The recent review of the CFP (Council regulation 2371/2002) incorporatedfurther environmental considerations, including application of the precautionaryprinciple to stock management and the progressive implementation of anecosystem-based approach to fisheries management.

Box 8.5 Ecological changes

Estimates for the North Sea suggestthat around a quarter of the totalbiomass of exploitable fish species ispresently removed by commercialfishing every year (Figure 8.8),together with a considerable mass ofnon-exploited fish species. This isclearly a substantial quantity and islikely to constitute a significantmodification of the North Seaecosystem. By examining past records,Greenstreet et al. (1999b)demonstrated that selected areas offeastern and north-eastern Scotland thathistorically had supported prolongedfishing pressure had undergonechanges in demersal fish communitystructure over a 72-year period.Where fishing was most intense, alongthe eastern Scottish seaboard, a

consistent decrease in diversity coupledwith the dominance of a few specieswas detected in non-target fishpopulations. Statistical analyses suggestthat these changes may have occurredin the late 1970s or early 1980s,perhaps reflecting the increase in theuse of demersal gears.Similarly, Rogers and Ellis (2000)reported length–frequency distributionchanges in both exploited and non-target species from the North Sea andIrish Sea over an 80-year period infavour of smaller individuals. There wasalso a coincident increase in theabundance of smaller, non-targetspecies, and it has been suggested thata continuous removal of largerpredatory fish, such as cod, may beimplicated in the observed increases instocks of juveniles and smaller fish.

Remainder (38%)

Seals (2%)

Harbour Porpoise (2%)

Seabirds (3%) Fishing (landings) (25%)

Fish (30%)

Figure 8.8 The fate of fish in the North SeaCompiled from the following sources: ICES, 1991;Hislop, 1992; Fifth International Conference on theProtection of the North Sea, 1997; Camphuysenand Garthe, 2000; SMRU, personalcommunication.

Northern gannets (Morus bassanus) feeding ondiscarded fish. L. Campbell

Fishing boats in Mallaig harbour.D. Donnan


Gear type

Otter trawl (pairand twin)

Beam trawl

Demersal pairtrawl

Twin trawl

Seines and ringnets

Pair seine

Dredges

Shrimp beamtrawl

Prawn trawl

Industrial trawls

Penetration depth

Ground rope, bobbins chains:

<5 cm (soft bottom)

<2 cm (hard bottom)

Trawl door6–20 cm (soft bottom

Chains:

4–8 cm (soft bottom)

3–6 cm (hard bottom)

Trawl heads: 7–10 cmCombined effect of beamtrawling in other areas:<10–20 cm deep tracksnoted

Ground rope 1–2 cm

Same as for otter trawl butwithout door

Zero

Zero

Mussel dredge: 5–25 cmCockle dredge: 5 cmScallop dredge: 3–10 cmHydraulic dredge: 25–60 cm

Bobbins 2 cm

Bobbins 2 cm

Same as for otter trawl

Species affected

Epifauna

North Sea: Crustacea (Corystes,Eupagurus), Mollusca (Abra alba,Arctica islandica, Donax vittatus, Spisulasubtruncata, Placopecten),Echinodermata (Echinocardium,Psammechinus miliaris), Cnidaria(Alcyonium digitatum)

Celtic Sea: Mollusca (Arctica islandica),Polychaeta (Lanice conchilega,Spiophanes bombyx), Echinodermata(Echinocardium cordatum, Asteriasrubens)

Epifauna

North Sea: same as otter trawl, plusPolychaeta (Pectinaria spp., Aphroditeaculeata), Sipunculida and Ascidiacea,Mollusca (Tellimya ferruginosa, Turritellacommunis, Chamelea gallina, Dosinialupinus, Mactra corallina)

Celtic Sea: Same as otter trawl, plusPolychaeta (Nephthys hombergii),Mollusca (Corbula gibba) and Tanaidcopepods



Minimal effect on benthos

Minimal effect on benthos

Same as for beam trawl

Molluscs, surface-grazing gastropods(Hydrobia ulvae); long-term effects onlarge bivalves likely. Polychaeta:(Pygospio elegans, Lanice conchilega)

Benthos and juvenile fish

Benthos and juvenile fish

same as for otter trawl

Estimated area trawled

Region II: 99,000 km2

(entire North Sea)

Region III: 25% of Irish Sea


(area between ShetlandIslands and Hardangerfjord,and the Straits of Dover)

Region III: 22% of Irish Sea


(entire North Sea)

Region II: 245 km2 (entireNorth Sea)

Region II: estuarine andcoastal areas of North SeaRegion III: 8% of Irish Sea

Region II: estuarine andcoastal areas of North Sea

Region II: northern NorthSea

Region II: 11,000 km2 pairtrawl (central North Sea),127,000 km2 single trawl(entire North Sea)

Table 8.3 Effects of different types of fishing gear on seabed disturbance, some of the species affected and estimated area trawled in OSPAR regions II (greater North Sea) and III (Celtic Sea)Sources: after Kaiser et al., 1996; Fifth International Conference on the Protection of the North Sea, 1997; Gubbay and Knappman, 1999; OSPAR Commission, 2000)


decoupling scheme (for species often caught withcod), which allows increases in the quota of otherspecies, with substantial increases in the quota forhaddock (+53%) and Nephrops (+30%).

Conservation concerns are founded, not least, onparallels between the present state of Europeancod stocks and that of the Canadian cod fisheryjust prior to its catastrophic collapse in the early1990s (MacGarvin, 2001). The Canadianexperience has shown that a failure to introducerapid and appropriate action may leave stocks at alevel from which recovery may not be possible inthe foreseeable future.

In view of the potential ecological consequencesof overexploitation (Box 8.5), commerciallyexploited fish species have been identified forconservation action through a UK GroupedSpecies Biodiversity Action Plan. This reaffirmsthe need to maintain all stocks inside ICES-defined precautionary reference points.

Fleets subject to EU regulations are obliged todiscard undersized fish, but fish of commerciallyacceptable size must also be discarded if catchesare in excess of quotas, or if the condition of aproportion of the catch threatens to affectgrading and thus reduce economic returns. Thegreat majority of the returned fish are alreadydead or do not survive.

In the North Sea demersal fishery the estimatedaverage proportions of cod and haddockdiscarded are 22% and 36%, respectively, byweight, representing 51% and 49% by numbers.Only approximately half of the plaice caught bybeam trawl may be retained, decreasing to 20% inshallower inshore grounds. For every tonne ofNorway lobster landed from the Irish Sea trawlfishery just under half a tonne of whiting isdiscarded as bycatch.

The impact of fishing gear, particularly trawls anddredges, on seabed habitats and species is afurther area of concern (Table 8.3). Jennings andReynolds (2000) outlined the likely ways in whichfishing may influence species diversity:

● by killing target and non-target species of fishor invertebrates;

● by modifying the ecological relationshipbetween species;

● by changing habitat structure.

Examples of the first and, to some extent, thesecond point in relation to fish populations are

discussed above, but direct evidence of lastingeffects on the benthos has been difficult todemonstrate. This is primarily due to the lack ofopportunities for study on areas entirely free ofpresent and past fishing and the inability todisentangle the influence of other factors such asclimate change and eutrophication (Jennings andReynolds, 2000). Rumohr and Kujawski (2000)examined one of the few benthic data sets thatallow comparisons between past (1902–1912) andcontemporary (1986) North Sea communities.They concluded that there had been a decline inbivalve mollusc abundance, but scavenging orpredatory crustaceans, gastropods and starfishhad increased in abundance in response to theavailability of fishery discards and animals killedor injured by the passage of fishing gear. Theseconclusions remain controversial and. althoughFrid et al. (2000), in a similar study, found someevidence for benthic community changes in threeof five selected areas of the North Sea, they wereunable to detect a decrease in bivalve abundance.

The state of commercially exploited fishpopulations and the ecological effects of the gearused to catch them are of serious concern. Thereis an overwhelming consensus of scientificopinion that fishing activity has, and continues tohave, an impact on the entire north-easternAtlantic region and may even be the mainecological structuring force on the benthos inareas of intense exploitation (Lindboom and deGroot, 1998).

The management of natural resources aseconomic commodities has brought somecommercially exploited fish stocks close tocollapse. A review of the CFP in 2002 acceptedthat the capacity of the European Communityfishing fleet often far exceeds that required forsustainable harvesting. An ecosystem-basedapproach, based on an integrated fisheriesmanagement policy that takes account ofecological community structure, is imperative. Forexample, protection from fishing in ‘no-takezones’ can provide not only a refuge for exploitedand other vulnerable species, but an environmentin which the target species can grow larger andproduce more offspring. This has been shown toenhance populations outside the protected areas(Roberts and Hawkins, 2000; Roberts et al., 2001).


Sources of dataInformation relating to the size of the Scottishfishing fleet, employment statistics and fishlandings data are produced by the ScottishExecutive and published yearly in a ScottishFisheries Statistics document (also available at theweb sitehttp://www.scotland.gov.uk/stats/bulletins/sfs02-00.asp.

The biological data used to determine the statusof fish stocks and the subsequent quotas formember EU states are collected by a range oforganisations and institutions operatingthroughout European waters. These data are thenused by ICES working groups to make stockassessments, which are then considered by theAdvisory Committee on Fishery Management(ACFM). The ACFM advice, together with all ofthe supporting data, are published annually in theICES Cooperative Research Report Series (alsoavailable at the web sitehttp://www.ices.dk/committe/acfm/comwork/report/asp/acfmrep.asp).

The provision of data through ICES has changedin 2003, with more mixed fishery considerationsand the inclusion of a wider range of species.The advice is being provided through a series ofoverviews for different areas and fisheries(although the advice is also still available on aspecies and area level).

ReferencesCamphuysen, C. J. and Garthe, S. (2000).Seabirds and commercial fisheries: populationtrends of piscivorous seabirds explained? In: Effectsof Fishing on Non-target Species and Habitats.Kaiser, M. J. and de Groot, S. J. (eds), pp.163–184 Blackwell Science, Oxford.

Coull, J. R. (1996). The Sea Fisheries of Scotland.A Historical Geography. John Donald Publishers,Edinburgh.

Cushing, D. H. (1988). The Provident Sea. Cambridge University Press, Cambridge.

FAO. (2000). The State of World Fisheries andAquaculture 2000. Food and AgricultureOrganisation of the United Nations, Rome.

Fifth International Conference on the Protection ofthe North Sea. (1997). Assessment report onfisheries and fisheries related species and habitatsissues. In: Svelle, M., Aarefjord, H., Heir, H. T. andØverland, S. (eds) Report from the Committee ofNorth Sea Senior Officials to the IntermediateMinisterial Meeting on the Integration of Fisheriesand Environmental Issues, 1997 (IMM 97). Bergen.

Frid, C. L. J., Harwood, K. G., Hall, S. J. and Hall,J. A. (2000). Long-term changes in the benthiccommunities on North Sea fishing grounds. ICESJournal of Marine Science 57: 1303–1309.

Greenstreet, S. P. R., Spence, F. B., Shanks, A. M.and McMillan, J. A. (1999a). Fishing effects innortheast Atlantic shelf seas: patterns in fishingeffort, diversity and community structure. II. Trendsin fishing effort in the North Sea by UK registeredvessels landing in Scotland. Fisheries Research 40:107–124.

Greenstreet, S. P. R., Spence, F. E. and McMillan,J. A. (1999b). Fishing effects in northeast Atlanticshelf seas: patterns in fishing effort, diversity andcommunity structure. V. Changes in structure of theNorth Sea groundfish species assemblage between1925 and 1996. Fisheries Research 40:153–183.

Gubbay, S. and Knapman, P. A. (1999). A reviewof the effects of fishing within UK European marinesites (UK Marine SACs Project). English Nature,Peterborough.

Hislop, J. (1992). The North Sea fishery: a casestudy. In: Proceedings of the 1992 Meeting of theEuropean Cetacean Society. European CetaceanSociety San Remo, Italy.

Hutchings, J. A. (2000). Collapse and recovery ofmarine fishes. Nature 406: 882–885.

ICES. (1991). Report of the MultispeciesAssessment Working Group. ICES, CM1991/Assess: 7.

ICES. (2001). Report of the ICES AdvisoryCommittee on Fishery Management, 2001.International Council for the Exploration of the Sea, ICES Cooperative Research Report, No. 246. ICES,Copenhagen.


ICES. (2002). Report of the ICES AdvisoryCommittee on Fishery Management. ICES,Copenhagen.

ICES. (2003). Report of the ICES AdvisoryCommittee on Fishery Management. ICES,Copenhagen.

Jennings, S. and Reynolds, J. D. (2000). Impacts offishing on diversity: from pattern to process. In: TheEffects of Fishing on Non-target Species andHabitats. Biological, Conservation and Socio-economic Issues. Kaiser, M. J. and de Groot, S. J.(eds), pp. 235–250. Blackwell Science, London.

Jennings, S., Alvsvåg, J., Cotter, A. J., Ehrich, S.,Greenstreet, S. P. R., Jarre-Teichmann, A.,Mergardt, N., Rijnsdorp, A. D. and Smedstadt, O.(1999). Fishing effects in northeast Atlantic shelfseas: patterns in fishing effort, diversity andcommunity structure. III. International fishing effortin the North Sea: an analysis of temporal andspatial trends. Fisheries Research 40: 125–134.

Jennings, S., Warr, K. J., Greensreet, S. P. R. andCotter, A. J. R. (2000). Spatial and temporalpatterns in North Sea fishing effort. In: The Effectsof Fishing on Non-target Species and Habitats.Biological, Conservation and Socio-economicIssues. Kaiser, M. J. and de Groot, S. J. (eds), pp.3–14. Blackwell Science, London.

Kaiser, M. J., Hill, A. S., Ramsay, K., Spencer, B.E., Brand, A. R., Veale, L. O., Prudden, K., Rees,E. I. S., Munday, B. W., Ball, B. and Hawkins, S. J.(1996). Benthic disturbance by fishing gear in theIrish Sea: a comparison of beam trawling and

scallop dredging. Aquatic Conservation: Marineand Freshwater Ecosystems 6: 269–285.

Lindboom, H. J. and de Groot, S. J. (eds). (1998).The Effects of Different Types of Fisheries on theNorth Sea and Irish Sea Benthic Ecosystems. NOIZ-Rapport. 1998-1/RIVO-DLO Report C003/98.

MacGarvin, M. (2001). Now or Never. The Costof Canada’s Cod Collapse and Disturbing Parallelswith the UK. WWF-UK, Godalming.

OSPAR Commission. (2000). Quality Status Report2000. OSPAR Commission, London.

Roberts, C. M., Bohnsack, J. A., Gell, F., Hawkins,J. P. and Goodridge, R. (2001). Effects of marinereserves on adjacent waters. Science 294:1920–1923.

Roberts, C. M. and Hawkins, J. P. (2000). Fully-Protected Marine Reserves: a Guide. WWF,Washington, DC, and University of York, York.

Rogers, S. I. and Ellis, J. R. (2000). Changes in thedemersal fish assemblages of British coastal watersduring the 20th century. ICES Journal of MarineScience 57: 866–881.

Rumohr, H. and Kujawski, T. (2000). The impact oftrawl fishery on the epifauna of the southern NorthSea. ICES Journal of Marine Science 57:1389–1394.

Scottish Executive. (2001, 2002). Scottish SeaFisheries Statistics 2000, 2001. Scottish Executive,Edinburgh.


Deep-water fish and fisheries9

IntroductionThe decline of European continental shelffisheries, increased catch unreliability and theintroduction of fishing quotas have coincidedwith a growing interest in the exploitation ofspecies that are considered largely outside therange of conventional fishing gear.

Despite often being portrayed as a dark andrelatively lifeless environment, the zone below adepth of 400 m – defined as ‘deep water’ by theICES – supports a diverse and abundant fishcommunity. Towed fine-mesh nets deployed forresearch purposes in the Rockall Trough andalong the continental slope have recovered over130 species, with an abundance peak roughlycorresponding to the 1,000-m depth contour. Ofthese, around 12 species are consideredmarketable (Table 9.1). Many of the targetspecies have distinct but overlapping depth

Figure 9.1 Vertical distribution of commercial fish in Rockall TrenchCrown copyright 2000. Reproduced with the permission of the FRSMarine Laboratory, Aberdeen.

Species

Micromesistius poutassou

Molva dyptergia

Phycis blennoides

Mora moro

Antimora rostrata

Coryphaenoides rupestris

Aphanopus carbo

Hoplostethus atlanticus

Argentina silus

Brosme brosme

Centroscymnus coelolepsis

Centrophorus squamosus

Common name

Blue whiting

Blue ling

Greater forkbeard

Mora

Blue hake

Roundnose grenadier

Black scabbardfish

Orange roughy

Greater silver smelt or argentine

Tusk

Portuguese dogfish

Leafscale gulper shark

State of stock/fishery

Considered to be harvested outside safe biological limits

Total French landings peaked at 14,000 tonnes in 1985, butfell to only 3,000 tonnes in 1994 and have since remainedstable. Currently considered to be harvested outside safebiological limits

Status of stock unknown


Owing to the technical problems of fishing at the depth ofgreatest density, commercial exploitation is currently notconsidered viable

Status of stock uncertain or unknown

Catches currently stable at around 6,000 tonnes butconsidered to be harvested outside safe biological limits

Landings by French vessels in the Rockall Trough peaked at3,500 tonnes in 1991 but then declined rapidly to less than500 tonnes as concentrations became heavily depleted.Currently considered to be harvested outside safe biologicallimits


Considered to be harvested outside safe biological limits

French landings of both shark species combined reached amaximum of approximately 3,000 tonnes in 1993, andhave remained stable at this level

Table 9.1Commerciallyexploited deep-water fishspecies Sources: FRS MarineLaboratory, Aberdeen;Gordon andHunter,1994; CES,2000; Gordon, 2001a

Top: Blue ling, centre: Orange roughy, bottom: Portuguese dogfish. SAMS


but by the late 1980s demand for other deep-water species formerly landed as bycatch began togrow. By 1992, larger French vessels hadextended their fishing activities still deeper inpursuit of the valuable orange roughy(Hoplostethus atlanticus) stocks (Gordon, 2001b).

The French fleet continues to be the most activealong the continental slope, with the major effortconcentrated around the Rockall Trough andRosemary Bank (Figure 9.2). Markets have,however, developed in Spain and the UnitedStates, and increasing numbers of Norwegian,Icelandic and Faeroes vessels have begun trawlingand longlining in the deep water. Both Irelandand the UK have commenced limitedexploitation (Brennan and Gormley, 1999), butlandings by Scottish vessels are largely of deep-water monkfish (Lophius piscatorius), with otherspecies retained as bycatch. Irish fishing startedaround 1988, but a rapid decline in one of thetarget species, the greater argentine (Argentina

silus), coupled with damage sustained to expensivegear, forced the fishery to close in 1990.

Deep-water fisheries have developed rapidly overthe last 10 years, but landings of most speciesdeclined soon after commencement ofexploitation (Figure 9.3). Although there was anapparent increase in the availability of orangeroughy, it is thought that this simply reflectsdiscovery and subsequent fishing of previouslyunexploited aggregations.

Catch per unit effort, a measure of how difficulta given species is to catch and thus an indicationof how abundant it may be, has been calculatedfor a limited number of deep-water species(Figure 9.4). By that measure, black scabbardfish(Aphanopus carbo), roundnose grenadier and blueling have all become scarcer.

Issues and implicationsDeep-water fish largely conform to the lifehistory adaptations of much of the deep-waterbiota, with slow growth rates, long naturallifespans and maturation at a high age. Thesecharacteristics render them particularly vulnerableto over-exploitation, and the rapid decline inlandings has given rise to concerns that thecurrent level of exploitation may beunsustainable. In addition, rapid pressuretransition associated with recovery from suchgreat depths and the delicate nature of much ofthe deep-water biota results in high bycatchmortality.

At present, deep-water fisheries are partiallyregulated, although for most species the status is

ranges (Figure 9.1), or may perform dailymigrations to feed at or near the surface.

Some deep-water fisheries are historically wellestablished, notably around oceanic islands withsteep inshore slopes, such as Madeira and theAzores, but exploitation of the fishery to thenorth-west and west of Scotland is a relativelyrecent development.

TrendsBottom trawling along the continental slopes ofnorthern Europe began in the late 1960s, whenthe former Soviet Union and other easternEuropean countries began targeting roundnosegrenadier (Coryphaenoides rupestris).

Among 12 commercially exploited deep-waterspecies (Table 9.1), five are considered to beharvested outside safe biological limits and thestatus of others is largely unknown.

Rapidly increasing catches peaked in the 1970s,but the break-up of the Soviet Union, coupledwith the introduction of 200-mile fishery limitsaround Europe and Iceland, contributed to adecline of the fishery. Attempts by other nations,notably Germany and the UK, to develop deep-water fisheries failed through lack of consumerinterest. In the late 1970s, French trawlers,traditionally operating along the outer shelf,began moving into deeper water. A market wasestablished initially for blue ling (Molva dyptergia),

Figure 9.2 Hours fished by French Trawlers landing in Scotland in 1998Source: FRS Marine Laboratory, Aberdeen.Crown copyright 2000. Reproduced with the permission of the FRSMarine Laboratory, Aberdeen.


unknown or they are believed to be harvestedoutside safe biological limits. Recent advice to theEU recommends an immediate reduction in thesefisheries unless they can be shown to besustainable (ICES, 2001).

Deep-water fishing, although not of the intensityof the shallower fisheries, may still constitute a

destructive influence on the often fragile habitatsand species. Trawl marks on the sea bed betweendepths of 200 and 1,400 m have been observedall along the north-east Atlantic shelf break andmay form continuous furrows for up to 4 km(Rogers, 1999; Fosså et al., 2000; Roberts et al.,2000; Hall-Spencer et al., 2002). The impacts ofsuch disturbance on sedimentary habitats areunknown, but the physical effects on hardersubstrates, particularly deep-water coral reefs, areperhaps easier to assess. Reef structuresdominated largely by Lophelia pertusa, butincorporating a number of other coral species,are present throughout the North Atlantic, withlarge aggregations in Norwegian waters andsmaller, scattered colonies widely distributed tothe west of Shetland. These structures support arich associated fauna, with over 850 species livingon or within the reefs of the north-easternAtlantic (Rogers, 1999). A single reef habitat maybe host to some 200–300 species.

The complex topography of Lophelia reefsprovides a particularly favoured habitat for non-target and target fish species, simultaneouslysupplying a refuge from predators and access to ahigh concentration of prey items. Consequently,fishing vessels in pursuit of the highest densities

0

3000

6000

9000

12000

15000

199719921987198219771972

YEAR

TON

NES

Blue Ling

Roundnose Grenadier

Black Scabbardfish

Orange Roughy

Figure 9. 3 Landingsof deep-sea fish speciesfrom the west ofScotland Sources: ICES; J.Gordon, DML.

50

100

150

200

250

19971995199319911989

YEAR

CPU

E (k

g/h)

Black Scabbardfish

a.

Figure 9.4 Trends in catch per unit effort (CPUE) for four deep-water fish species. Dataderived from a reference fleet of French deep-water trawlers operating in ICESareas VI (west of Scotland) and VII (west, south-west and south of Ireland). Redrawn from ICES (2000).

0

100

200

300

400

500

1997199519931991

YEAR

CPU

E (k

g/h)

Orange Roughy

Area VI

Area VII

d.

0

200

400

600

800

1000

1997199519931991198919871985

YEAR

CPU

E (k

g/h)

Blue Ling

c.

100

200

300

400

500

600

19971995199319911989

YEAR

CPU

E (k

g/h)

Roundnose Grenadier

b.


of exploitable species often recover sections ofreef after hauling in their trawling gear (Hall-Spencer et al., 2002).

Prospects for deep-water habitats and the speciesthat inhabit them are bleak unless internationallyenforced conservation measures are put in place.In recognition of the further potential forunregulated overexploitation and a lack ofdetailed information on the biology of deep-water species, a UK Grouped Biodiversity ActionPlan for deep-water fishes is being implemented(UK Biodiversity Group, 1999) with the objectiveof stabilising all stocks of commercially exploitedspecies at or above safe biological limits by 2005.

Designation of SACs under the HabitatsDirective is being considered for deep-water coralreefs, but such protection will apply only tofeatures within precisely defined areas. Whiledesignation as a SAC under the HabitatsDirective will require incorporation into UKlegislation, fisheries are controlled at theEuropean level. Protection of both corals anddeep-water fish requires the EC to exercisecontrol over fishing in these designated sitesthrough amendments to the CFP. In 2002 the ECinitiated a series of measures (Council Regulation(EC) No.2347/2002) designed to regulate andmonitor deep-water fishing activity. Thesemeasures include the issuing of licences forlanding deep-water species and the placing ofindependent scientific observers on boardlicensed vessels. In addition, fishing activities areclosely monitored through a satellite trackingsystem fitted on each vessel. This managementscheme will be reviewed and a report submittedto the European Commission before the 30thJune 2005.

Sources of dataPopulation estimates of deep-water species foundon the slopes of the Rockall Trough are derivedfrom an intensive programme of study carriedout by the Scottish Association for MarineScience (SAMS) since the mid-1970s.

Fishery landings data for some deep-waterspecies are compiled and collated by the ICESAdvisory Committee on Fishery Management(ACFM) and published in the ICES Cooperative

Research Report Series (also available at the web sitehttp://www.ices.dk/committe/acfm/comwork/report/asp/acfmrep.asp). Reported landings fromthe earlier exploration of the sea fishery forroundnose grenadier are considered to beinadequate, and the common practice ofreporting landings of roundnose and roughheadgrenadier as a single species continues toconfound attempts at accurate stock assessment

(Gordon, 2001a,b). In addition, deep-waterspecies captured as bycatch are probably greatlyunder-reported. There are concerns that the UKadoption of the United Nation Convention onthe Law of the Sea and the resulting removal ofthe UK 200-mile fishery limit around Rockall hasled to a greater degree of uncontrolledexploitation. Although the enclosed area, whichincludes the Rockall Plateau and Hatton Banks,was not previously subject to any officiallyrecognised regulation policy for deep-sea fishes,the number of vessels was restricted bynationality and reliable data on landings werecollected. At present, landings are known to beincorrectly and erratically reported as a largelyinternational fleet engages in a programme ofexploration and exploitation.

ReferencesBrennan, M. H. and Gormley, R. T. (1999). TheQuality of Under-utilised Deep-water Fish Species.Irish Agriculture and Food Development Authority,Dublin.Fosså, J. H., Mortensen, P. B. and Furevik, D. M.(2000). Lophelia-korallrev langs norskekystenforekomst og tilstand. Fisken og Havet 2: 1–94.Gordon, J. D. M. (2001a). Deep Ocean Fisheries.Joint Nature Conservation Committee,Peterborough.Gordon, J. D. M. (2001b). Deep-water fish andfisheries: introduction. Fisheries Research 51:105–111.Gordon, J. D. M. and Hunter, J. E. (1994). Studyof Deep-water Fish Stocks to the West of Scotland.Vol. I. Final Report. Scottish Association for MarineScience, Oban.Hall-Spencer, J., Allain, V. and Fosså, J. H. (2002).Trawling damage to NE Atlantic ancient coralreefs. Proceedings of the Royal Society of London,Series B 269: 507–511.ICES. (2000). Advisory Committee on FisheryManagement. Report 2000. ICES, Copenhagen.ICES. (2001). Report of the ICES AdvisoryCommittee on Fishery Management, 2001. ICESCooperative Research Report, No. 246. ICES,Copenhagen.Roberts, J. M., Harvey, S. M., Lamont, P. A., Gage,J. D. and Humphery, J. D. (2000). Seabedphotography, environmental assessment andevidence for deep-water trawling on the continentalmargin west of the Hebrides. Hydrobiologia 441:173–183.Rogers, A. D. (1999). The biology of Lopheliapertusa (Linnaeus 1758) and other deep-water reef-forming corals and impacts from human activities.Internationale Revue der gesamten Hydrobiologie84: 315–406.UK Biodiversity Group. (1999). Tranche 2 Actionplans. Vol. V: Maritime Species and Habitats.English Nature, Peterborough.

Quality of the marine environmentPart 4


Coastal and estuarine environment quality10

IntroductionIn 1960, River Purification Boards (RPBs) weregiven responsibility for monitoring andimproving the levels of new discharges to tidalwaters. From 1965 they became responsible forall discharges; nevertheless, river water wasconsidered a priority and domestic and industrialdischarges to estuaries and coasts remainedlargely untreated (Saunders et al., 2002). In the1970s a programme of discharge controls wasinitiated and major improvements in estuarineand coastal water quality followed.

Two-thirds of Scotland’s coastal traffic is of bulkliquid, primarily crude petroleum from North Seaterminals. Accidental spillage is an ever-presentthreat to marine habitats (Box 10.1).

To assist in the assessment of water quality theRPBs developed classification schemes in whichbiological and chemical sampling data werecombined to provide a single index of water

Box 10.1 Shipping

Over 80% of the world’s commodities are transported byshipping. Sea-borne freight traffic around Europe and theUK has continued to increase. In 2000, the Forth andSullom Voe ports accounted for cargoes of 41.1 and 38.2million tonnes respectively, making them the fourth and fifthlargest ports by volume in the UK (DTLR, 2001).Each year, many pollution incidents occur around Scotland,involving vessels from large bulk carriers to smallercoasters, ferries, fishing boats and recreational craft. Many,mainly those involving small spillages of oil, go unreported.Occasionally, as in January 1993 with the wreck of the oiltanker MV Braer on the southern coast of Shetland, a majorpollution incident may arise. Such an occurrence can havea devastating and immediate impact on the localenvironment, wildlife and coastal amenity. Local economicand social interests can be similarly affected. In the longerterm, however, oil contamination will eventually disappearthrough the action of natural processes.On average, around 60 pollution incidents per yearinvolving oil or chemical contamination are brought to theattention of SNH, which provides advice on naturalheritage implications and appropriate mitigation measures.Referrals come from the Maritime Coastguard Agency,harbour authorities and local authorities.

Previous page: Knotted wrack (Ascophyllum nodosum).G. Saunders

Above: Coll.L. Gill/SNH

The wreck of the MV Braer, Shetland.G. Storey


quality. Annual assessments of this type were firstapplied in 1968, but no improvement in waterquality was observed until after 1975. Separateschemes for coastal and estuarine classificationwere introduced in 1990, and improvements inwater quality were reported between 1990 and1995.

In 1995, SEPA was established under theEnvironment Act 1995 and assumed statutoryresponsibility for Scotland’s tidal waters. Thecoastal and estuarine classification schemescontinued to be applied by SEPA but wereimmediately subject to substantial revision toincrease monitoring sensitivity. A further revisionfor coastal water quality assessment,incorporating additional island and othercoastlines, was applied to data from 1999onwards.

In 1999, annual monitoring was extended from6,900 km to 11,800 km of coastline, togetherwith 810 km2 of estuarine catchment. Data arecollected on water quality, seabed invertebratequality, the status of fish populations andobservations of aesthetic modifications. Gradingis on the basis of four classes: excellent, good,unsatisfactory and seriously polluted (seeAppendices 1 and 2 for an explanation ofclassification schemes).

The EC Bathing Water Directive (76/160/EEC)requires member states to identify bathing watersand improve or maintain them at a prescribedstandard. The UK government set a definition ofa bathing site based on the number of peopleusing the area as a bathing destination. A totalScottish set of 23 was announced in 1987 by theSecretary of State for Scotland. A review by theScottish Office resulted in the addition of afurther 37 bathing waters in May 1998. TheBathing Waters (Classification) (Scotland)Regulations 1991 implements the 19 monitoringand interpretation parameters specified by the EC

Bathing Water Directive. The Directive specifiestwo main water quality standards:

● mandatory – minimum standards which mustbe met by member states;

● guideline – stricter values that member statesshould endeavour to observe.

The microbiological requirements for each aregiven in Appendix 3.

TrendsThe overall quality of Scottish coastal waters waspredominantly excellent or good between 1996and 2002, with little more than 260 km, about3%, of the coastline classified as unsatisfactory orseriously polluted at any time (Figure 10.1). Ingeneral, the areas rated as polluted were localisedcontaminated sites, around long sea outfalls,inappropriately sited fish farms or sludge andspoil dumping sites.

The majority of Scottish estuarine areas alsomaintained a favourable overall rating between1996 and 2002. About 35 km2 was classed asunsatisfactory or seriously polluted, but thisdeclined to 15.4 km2 in 2002. The small areasclassified as seriously polluted were highlylocalised and were reduced by 60% over theperiod (Figure 10.2).

Land-based industrial development andsubsequent urbanisation has, in general, beenrestricted to the areas surrounding the majorinlets or firths of the Central Belt. Of a totalScottish population of 5.2 million, about 1.8million people live around the Clyde estuarycatchment and a further 1 million around theFirths of Tay and Forth. The cumulative effectsof prolonged domestic and industrial dischargesfrom these areas into the nearby estuaries havebeen severe and persistent.

Below: Forth estuary.P. & A. Macdonald/SNH

Below right: Dog whelks(Nucella lapillus).J.Baxter


Figure 10.1 Coastal classification as a percentage of sites surveyed: (a) 1996–2000, (b) 1999–2002 (incorporating previously excluded costal areas). Percentagechange between start and end of reporting periods are shown in bracketsSource: SEPA.

Statutory controls on discharges have, however,promoted a steady recovery since the 1970s, andan increasing number of species are returningand re-establishing at locations where pastcontamination levels excluded all but a few highlytolerant taxa.

In the Clyde, a major reduction in seriouslypolluted areas was achieved between 1995 and1999 (Figure 10.3). In the 1970s, the upper Clydeestuary sediments were dominated by a fewpollution-tolerant species mainly consisting ofoligochaetes and the polychaete worm Capitella

capitata. In the 1980s, with improving waterquality, the faunal composition began to changein favour of a more diverse invertebratecommunity (Figure 10.4) and rising numbers offish species (Figure 10.5). The establishment ofresident populations of flounder was a furtherindication of improving water quality.

Similar improvements have occurred within theForth estuary. Bacterial oxygen consumption is anatural process, at its greatest in the upperreaches of estuaries where suspended particulatematter is most concentrated. The addition oforganic waste has historically stimulated microbialgrowth, measured as biological oxygen demand(BOD), in the Forth and depressed the level ofoxygen available to other fauna and flora. Asdischarges have declined, the extent and durationof oxygen depression have diminished (Figure10.6). The combination of increasing dissolvedoxygen and declining organic and metallic wastelevels has been linked to returning fishpopulations, notably the smelt (Osmerus eperlanus),a species known to be particularly sensitive to lowoxygen levels (Figure 10.7).

Contrary trends of species recovery on formerlypolluted mudflats (Box 10.2) and decliningnumbers of scaup (Aythya marila) in the Forthestuary (Box 10.3) are consistent with improvingecological status.

0

20

40

60

80

100

2002200120001999199819971996

PERC

ENTA

GE

Excellent (+4%)

Unsatisfactory (-57%)

Good (-4%)

Seriously polluted (-60%)

0

10

20

30

40

50

60

19991998199719961995

PERC

ENTA

GE

Excellent (+4%)

Unsatisfactory (+117%)

Good (+6%)

Seriously polluted (-93%)

Figure 10.2 Estuarine classification as a percentage of sites surveyed in 1996–2002.Percentage change between 1996 and 2002 shown in brackets. Source SEPA.

Figure 10.3 Clyde estuarine classification as a percentage of sites surveyed in 1995–1999.Percentage change between 1995 and 1999 shown in brackets Source: SEPA

0

20

40

60

80

100

2002200120001999

PERC

ENTA

GE

Excellent (+1.2%)

Unsatisfactory (-29.4%)

Good (-3.5%)

Seriously polluted (-54.5%)

b.

0

20

40

60

80

100

20001999199819971996

PERC

ENTA

GE

Excellent (-1.2%)

Unsatisfactory (-8.4%)

Good (+6.5%)

Seriously polluted (-13.5%)

a.


0

5

10

15

20

1996199419921990198819861984198219801974

NU

MBE

R O

F FS

PEC

IES

PRES

ENT

YEAR

Crustacea, molluscs and other polychaetes

Oligochaetes and Capitella capitata

Figure 10.5 Number of fish species recorded inthe Clyde Estuary 1978–1999 Source: SEPA

Figure 10.4 The composition ofbenthic fauna at theClyde/Cart confluence Source: SEPA

0

100

200

300

400

500

600

700

800

900

200220001998199619941992199019881986198419821980

YEAR

BOD

(g/s

)

Figure 10.6 Trends in biologicaloxygen demand (BOD)originating from pointsource discharges in theForth estuary.

0

10

20

30

40

50

60

70

199919971995199319911989198719851983

AVE

RAG

E A

BUN

DA

NC

E PE

R TR

AW

L

YEAR

Figure 10.7 Fish species recorded in the Forthestuary,1983–1999 Source: SEPA.

Inset: Smelt (Osmerus eperlanus).G. Saunders

20

30

40

50

97-9994-9690-9386-8982-8578-81

YEAR

NU

MBE

R O

F FI

SH S

PEC

IES


Box 10.2 Kinneil mudflats

A reduction in effluent discharges from an oil refineryadjacent to the Kinneil mudflats in the Firth of Forthpromoted recolonisation of the formerly almost lifelesssediments (Figure 10.8) (McLusky and Martins, 1998).

Box 10.3 Declining scaup(Aythya marila) numberson the Forth

The scaup is a diving duck,occurring mainly as a winter visitorin the UK, from Iceland, the BalticSea and Russia (Thom, 1986).During 1995–1999, peak counts ofscaup in Britain averaged around5,500, of which about 60–98%occurred in Scotland (Musgrove etal., 2001). The bulk of these werecounted in the Solway, Lochs Ryanand Indaal, the Inner Moray Firthand the Forth estuary.

Much higher numbers of scaup wererecorded in Scotland during the1960s, particularly on the Forth,where their numbers appeared to beinfluenced by the discharge of wastegrain and sewage. Grain dischargeinto the Forth increasedprogressively up to 1968, whenover 30,000 scaup were countedbetween Leith and Levenhall (Figure10.9). Declining scaup numbers insubsequent years reflected areduction in grain discharge levelsand, in 1975, the implementation ofa sewage treatment programme atSeafield (Thom, 1986).

0

5000

10000

15000

20000

25000

30000

19851980197519701965

Sewage treatmentprogramme implemented

YEAR

CO

UN

T

Figure 10.9 Peak counts of scaup wintering onthe Forth between Leith andLevenhall during the 1960s to1980s. Source: Thom, 1986.

Figure 10.8 Mean number of species of benthic

in fauna at Kinneil mudflats in theForth estuary

After McLusky and Martins, 1998.Kinneil mudflats.J.Baxter

Scaup (Aythya marila).E. Janes/RSPB

0

1

2

3

4

5

6

7

8

9

19971994199119881985198219791976

YEAR

MEA

N N

UM

BER

OF

SPEC

IES

PER

STAT

ION


Populations of the dogwhelk (Nucella lapillus)declined substantially throughout the 1980s andearly 1990s, becoming locally extinct at someregularly monitored locations around the UK.This was attributed to the widespread use oftributyltin (TBT), a chemical antifoulantcommonly applied to the hulls of marine vessels.High concentrations of TBT were shown to beassociated with a masculinisation effect on femaledogwhelks and other mollusc species, thusreducing their reproductive capacity. The mostsevere effects were found in the littoral zoneadjacent to areas of high vessel activity. In 1987,the UK imposed a ban on the use of TBT-basedantifouling treatments for vessels below 25 m inlength and this, together with the development ofslow-releasing paints for larger vessels, hasresulted in reduced TBT concentrations inestuarine and coastal waters. A study undertakenin 2001 indicated that dogwhelk populations hadre-established at almost all of the sites fromwhere they had disappeared as a result of highTBT levels (Birchenough et al., 2002). Scottishsampling locations included the Isle of Cumbraeand Lerwick harbour, Shetland. However, someareas of the south-west coastline, notably LochRyan, continued to exhibit elevated levels of TBTup to 1999. A possible source of thiscontamination may be a breaker’s yarddismantling large naval vessels (SEPA, 2000).

While peak counts for the estuary averaged 4,600during 1976-1979, numbers continued to fall inthe Leith-Levenhall section, reaching an averagepeak of only 50 birds in 1980-1983. During the1990s, peak counts for the estuary varied widely(77-1,031) but were still well below the figuresrecorded in the 1960s (Musgrove et al., 2001).

In 2001 only 85% of Scotland’s identified bathingwaters were able to meet the mandatory standard,of which only 40% were of a sufficient quality toattain the guideline standard. This represented noimprovement on the previous year and adeterioration when compared with 1998 and 1999(Figure 10.10). In 2002, however, there was anotable increase in the number reaching themandatory standard, resulting in some 92% ofScotland’s identified bathing waters attaining anacceptable standard or above. Over the longerterm there has been a steady reduction in failureto comply with the minimum standard (Figure10.11). Areas of persistent compliance failurehave been identified in Ayrshire and Argyll, andin the majority of cases this has been attributableto sewage effluent (SEPA, 2001).

Sewage sludge dumping from Glasgow andEdinburgh was discontinued in 1998 (Box 10.4).

Figure 10.11 Trends in Scottish bathing watercompliance failure, 1988–2002 Source: SEPA.

Figure 10.10 Quality assessments for Scotland’sidentified bathing waters,1997–2002Source: SEPA.

0 %

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1997 1998 1999 2000 2001 2002

Guideline passes

Mandatory passes onlyFailures

0 %

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1988 1990 1992 1994 1996 1998 2000 2002

Pass

Fail

100%90%80%70%60%50%40%30%20%10%0%

1997 1998 1999 2000 2001 2002

Guideline passes

Mandatory passes only

Failures

100%90%80%70%60%50%40%30%20%10%0%

1988 1990 1992 1994 1996 1998 2000 2002

Pass

Fail


Box 10.4 Effects of sewagesludge dumping

Sewage sludge from Edinburgh andGlasgow was dumped at sea until 1998,when dumping was stopped in compliancewith the EC Urban Waste Water TreatmentDirective (91/271/EEC).

Frequent monitoring of the dumping groundsshowed a greater impact at the Firth ofClyde Garroch Head (Glasgow) site, whichwas less dispersive than the two North Seasites used by Edinburgh. The dumpingground at Garroch Head was contaminatedby persistent organochlorine compounds(Kelly and Balls, 1995) and the benthosmodified by the organic input. Recent studieshave shown that the benthos has improvedsince dumping stopped. Sludge disposal offthe Firth of Forth had no discernibleecological impact, presumably because ofthe biodegradability and low concentrationof persistent contaminants in the dumpedmaterial (Saunders et al., 2002).

Issues and implicationsTo date, national and European legislationdirected towards regulating traditional pointsource discharges has successfully reduced theextent of polluted tidal waters. Where inputs oforganic waste and persistent substances havebeen reduced, the environment has shown signsof recovery. Nevertheless, problems associatedwith more diffuse pollution remain. Of greatestconcern is bacterial and nutrient contamination.

Diffuse inputs of faecal coliforms are underinvestigation as the probable cause of failures tomeet the standards of the Bathing WatersDirective in places where point source dischargeshave been largely eliminated (Centre for Researchinto Environment and Health, 1999).

Monitoring results for the Firth of Forth haveshown no trend in the concentrations of coastalnutrients or chlorophyll over the past 20 years(Dobson et al., 2004), whereas a local problemhas been recognised in the catchment and estuaryof the River Ythan (Box 10.5). A recent andmore general review of nitrogen inputs to tidalwaters has shown rivers to be the major source,

Box 10.5 Nutrientenrichment

Problems associated with diffusepollution, notably from bacterialcontamination and nutrientenrichment, remain in severalestuaries and particularly on the eastcoast. Whereas nutrient andchlorophyll concentrations haveremained largely unchanged in theFirth of Forth over the past 20 years,they have increased markedly in thearable catchment and estuary of theRiver Ythan.In the future, the EC WaterFramework Directive (WFD) willreplace and complement manyexisting directives and will provide aframework in which good ecologicalstatus is actively sought for all watersother than those heavily modified foressential services. Present policies oftolerating no deterioration inclassification status will continue, aswill control of point sources. Incontrast to past legislation, the WFDmaintains a more explicit focus ondiffuse inputs from agricultural andurban runoff, requiring someadjustments of emphasis relating tomonitoring and control.

Assessing algal biomass, Ythan estuary.SEPA

Extent of algal mats, Ythan estuary.SEPA


with relatively minor inputs from point sourcedischarges.

Sources of dataData relating to estuarine and coastal waterquality are collected annually by SEPA and areavailable electronically.

Bathing water is sampled at least once every twoweeks for total and faecal coliforms, transparency,colour, mineral oil, surface-active substancesreacting with methylene blue and phenols. Aminimum of 12 samples are taken during thebathing season. The results are publishedannually in the Scottish Bathing Waters document(SEPA, 2001, 2002, 2003).

SEPA datasets relating to all of the above can befound at:http://www.sepa.org.uk/data/index.htm.

ReferencesBirchenough, A. C., Evans, S. M., Moss, C. andWelch, R. (2002). Re-colonisation and recovery ofpopulations of dogwhelks Nucella lapillus (L.) onshores formerly subject to severe TBTcontamination. Marine Pollution Bulletin 44:652–659.

Centre for Research into Environment and Health.(1999). Faecal Indicator Organism Sources andBudgets for the Irvine and Girvan Catchments,Ayrshire., Vols 1 and 2. A report to WOSWA,SEPA and South Ayrshire Council.

Dobson, J., Edwards, A., Park, R. and Richardson, L. (2003). Decadal changes in theForth Estuary and Firth of Forth in relation to theNorth Sea 1980–1999. In: Burning Issues of NorthSea Ecology. The 14th International SenckenbergConference, ‘North Sea 2000’, Wilhelmshaven,Germany, 8–12 May 2000. Senckenbergianamaritima, 31, (2). Kröncke, I., Türkay, M.,Sündermann, J. (eds). E. Schweizerbart’scheVerlagsbuchhandlung, Stuttgart.

DTLR. (2001). Maritime Statistics: United Kingdom:2000. The Stationery Office, London.

Kelly, A. G. and Balls, P. W. (1995). Persistentorganochlorine compounds in the Firth of Clyde. In:Coastal Zone Topics: Process Ecology andManagement. 3. The Estuaries of Central Scotland.McLusky, D. S (ed.), pp. 88–97. Joint NatureConservation Committee, Peterborough.

McLusky, D. S. and Martins, T. (1998). Long-termstudy of an estuarine mudflat subjected to petro-chemical discharges. Marine Pollution Bulletin 36:791–798.

Musgrove, A., Pollitt, M., Hall, C., Hearn, R.,Holloway, S., Marshall, P., Robinson, J. andCranswick, P. (2001). The Wetland Bird Survey1999–2000: Wildfowl and Wader Counts.BTO/WWT/RSPB/JNCC, Slimbridge.

Saunders, G., Dobson, J. and Edwards, A. (2002).The state of Scotland’s seas and estuaries. In: TheState of Scotland’s Environment and NaturalHeritage. Usher, M. B., Mackey, E. C. and Curran,J. C. (eds). The Stationery Office, Edinburgh.

SEPA. (2000). West Region Water Quality Review.Scottish Environment Protection Agency, Stirling.

SEPA. (2001, 2002, 2003). Scottish BathingWaters 2001 (2002, 2003). SEPA, Stirling.

Thom, V. (1986). Birds in Scotland. T & A.D.Poyser, Calton.


Marine litter11

IntroductionThe accumulation of man-made debris is aconsiderable problem in the Scottish maritimeenvironment, on and within the open sea, on thesea bed and on the shore. Discarded material mayoriginate from either land or marine sources.Some 50-80% is estimated to be derived fromland-based activities such as refuse disposal,sewage discharge or tourism. Marine sources arepredominantly the shipping, fishing andmariculture industries. The offshore oil and gasindustry was a significant contributor in the past,but controls and improvements in wastemanagement practices have greatly reduced suchinputs. The main impacts of marine litter are asfollows:

● aesthetic degradation due to visual impact oflitter;

● associated economic losses due to decrease intourism;

● damage to boats and fishing gear;

● risk to human health from sewage-relateddebris or hazardous chemicals;

● hazards to wildlife, mainly from entanglementin discarded nets and ingested debris;

● introduction of non-native species fromcolonised floating debris transported bycurrents.

The nature of the materials themselves and wind,wave and tide action results in accumulation at, orabove, the high-water mark, where the debris isvisually intrusive. The problem is often increasedat times of the highest spring tides andconcurrent storms, commonly in early autumnand late winter. At these times winds may beparticularly strong and dry litter can be liftedfrom the strandline and deposited considerabledistances inland, where ‘snagging’ andaccumulation of plastic bags and wrappingmaterial on fencing, trees and hedges is common.In the absence of a clean-up policy, largeamounts of litter can remain on beaches forextended periods of time, undergoing acontinuous cycle of exposure and reburial by theaction of wind and tide, with smaller itemsremaining buried for longer (Williams and Tudor,2001).

In the sublittoral, the continental shelves andslopes have been subject to a continuousaccumulation of debris, consistent withconcentrations observed floating at the surface(Galgani et al., 2000). The composition andabundance of material can be traced to proximityto major rivers in the case of sewage-relateddebris, shipping lanes in the case of vessel-derived litter and areas of greatest fishingintensity in the case of lost or discarded fishingnets and other fishing-associated debris (Williamset al., 1993; Galgani et al., 2000).

Above: Beach litter.C. Duncan/MCS

Above right: Publicparticipation in littermonitoring, MCSBeachwatch, Cramond.C. Duncan/MCS


TrendsThe inconsistent manner in which data have beencollected and changes in reporting format make itdifficult to interpret trends. Results from annualcollections from two beaches on the east coast ofScotland show widely varying amounts betweensites and years but no consistent pattern ofchange (Figure 11.1). Other reports have,however, suggested that beach litter has increasedover the last 10 years (OSPAR Commission,2000a). Velander and Mocogni (1998) noted thatthe quantity of the litter found on Cramondbeach, Edinburgh, more than doubled between1984 and 1994, rising from 0.35 to 0.8 pieces oflitter per square metre.

Discarded material from tourist and recreationalactivities has been the greatest source of coastallitter (Figure 11.2), with commercial fishing andsewage-related debris the second and third largestsources respectively. There was a reduction inlitter originating from discharges from shippingbetween 1997 and 2002.

The bulk disposal of waste material at sea as analternative to landfill became particularlyprevalent in the second half of the twentiethcentury. In the 1980s the greatest proportion ofdumped material was derived from dredgingactivities, constituting some 80–90% of the totalamount of discarded material. Other types ofwaste disposed of at sea included industrialeffluent, sewage sludge, incineration products,mine tailings, redundant military ordinance (Box11.1) and shipping waste.

The dumping of dredged material continuesaround the UK, but licensing now enforcesgreater controls over the dumping location,amount and chemical constituents of the dredgedmaterial. The dumping at sea of other materialhas been addressed at an international level.Resultant UK legislation has put an end to themarine disposal of most types of waste. Disposalof radioactive waste at sea stopped at the end of1982, burning of waste at sea has not beenpermitted since 1990, dumping of industrialwaste stopped at the end of 1992 and dumpingof sewage sludge stopped at the end of 1998.

0

10

20

30

40

50

60

2002200120001999199819971996199519941993

ITEM

S/M

YEAR

a.Port Laing, Fife’

0

200

400

600

800

1000

200220012000199919981997

ITEM

S/KM

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Tourist/recreational

Non-sourced

Fishing

Sewage related debris

Shipping/galley waste

Fly-tipped

Medical

Figure 11.1 Total number of beachlitter items collectedbetween 1993 and2002 from two beacheson the east coast ofScotland Source: MarineConservation Society. (a)Port Laing, Fife. (b) Donto Ythan.

Figure 11.2 Sources of littercollected on Scottishbeaches between 1997and 2002Source: MarineConservation Society.

0

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4

5

2002200120001999199819971996199519941993

ITEM

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b.Don to Ythan


Figure 11.3 North Channel and northern IrishSea, showing the distribution anddensities of larger munitions,munitions-related materials andunidentified man-made debris,derived from combination of thesidescan sonar, underwatertelevision and pulse induction data(number of targets/squarekilometre)Crown copyright 2000.Reproduced with the permission ofthe FRS Marine Laboratory,Aberdeen.

Box 11.1 Munitions

Areas around the Scottish coast have beenused as dumping grounds for waste munitionsand more recently for disposal of chemicalweapons. Of the order of a million tonnes ofmunitions was dumped in the Irish Sea in theyears following the Second World War. Inrecent years, some of these materials, notablyphosphorus flares, have been washed up onbeaches or have been recovered in fishingnets. Underwater photography aroundsubmerged gas pipelines has revealedmunitions (GESAMP (IMO/FAO/UNESCO-IOC/WMO/WHO/IAEA/UN/UNEP JointGroup of Experts on the Scientific Aspects ofMarine Environmental Protection) andAdvisory Committee on Protection of the Sea,2001).

A survey carried out by the FisheriesResearch Services showed that discardedmunitions were distributed over a widearea and were commonly found outsidethe charted dump site (Figure 11.3).Examination of sediments and fish andshellfish tissue samples from the arearevealed no trace of chemical warfareagents, or explosive or propellantresidues. Metal levels were found to bewithin ranges found elsewhere in UKwaters and it was concluded that, at thattime, there was no measurable impact onthe benthos.


Issues and implicationsOver 10,000 tonnes of debris is removedannually from selected UK beaches at aconsiderable cost to local authorities. Out of atotal UK coastal clean-up expenditure of around£2 million between 1997 and 1998, over£494,000 was spent on disposal of litter removedfrom some 300 km (less than 2%) of the Scottishcoastline (Hall, 2000). In addition, floating debrisrepresents a significant economic problem for thefishing, fish farming and shipping industries.Working vessels may sustain damage by propelleror driveshaft fouling or blockage of the coolantintake. Catches may be damaged or contaminatedby coincident capture of debris, while thecapacity of the net is reduced and time is spenton litter removal.

Horseman (1982) highlighted the large amount ofwaste disposed of at sea by merchant shipping inthe early 1980s, pointing out that wrappings,cases, containers, packages, bottles and jars wereeventually thrown into the sea, ignoringinternational regulations prohibiting such actions.More recently, the UK Merchant Shipping andMaritime Security Act 1997, an amendment ofthe Merchant Shipping Act 1995, providespowers to introduce regulations implementingprovisions of international treaties (in particularMARPOL 73/78). In addition, the Act – madestatutory by the Merchant Shipping (Port WasteReception Facilities Regulations 1997) – places aresponsibility on port and harbour authorities toprovide adequate waste reception facilities and

prepare waste management plans. Theenforcement of these regulations may havecontributed to observed reductions of sea-bornelitter (Figure 11.2), but it remains difficult toobtain evidence of illegal disposal that isacceptable in a court of law, and prosecutions arerarely pursued.

Of all of the discarded materials that enter themarine environment it is plastic which attractsgreatest global concern. Durable, versatile andcheap to produce, plastics have replaced many ofthe traditional manufacturing materials such asmetal, glass and wood, with a world-wide demandin excess of 100 million tonnes per annum.Plastics are used to the exclusion of almost allother materials in the packaging, consumer andfishing industries, and it is largely through theseroutes that an estimated 10% of all globalproduction finds its way into the sea. In theNorth Sea region non-degradable plastic mayconstitute 95% of discarded debris (OSPARCommission, 2000b).

Plastics are notoriously resistant to degradation,and once thrown away may persist andaccumulate in the environment for many years.The degradation process is slower in seawaterthan in air, but plastics do eventually break downinto constituent fibres, which may become amajor component of beach sediments (MarineConservation Society, 2001).

Plastic objects are of relatively low density andwill commonly float or drift in the water column,fouling fishing gear and presenting hazards tosmall craft and marine wildlife. Seabirds areknown to be particularly susceptible to ingestionof litter and may pass items on to their chicks byregurgitation. Turtles are vulnerable also (Box11.2).

Floating plastic debris is now the most commonman-made item found at sea. Wind and currentscan transport these items considerable distancesresulting in the coastal deposition of items frommany different countries. A wide variety ofanimal species are able to colonise floating debris,increasing opportunities for the establishment ofnon-native species by as much three times in thetemperate latitudes (Barnes, 2002).

Entanglement of marine mammals, birds, fishand shellfish in larger pieces is a frequentoccurrence, with drowning or slow starvationcommon consequences (Laist, 1997). The overallincidences of entanglement are likely to beunder-reported (Table 11.1).

Beach litter.G. Saunders


Box 11.2 Turtles

The critically endangered leatherback turtle, (Dermochelyscoriacea) is a regular, albeit uncommon, summer visitor.Of 86 turtle sightings in British and Irish waters in 2002,60 were leatherbacks. Most Scottish sightings occur offthe west and north coasts.

Entanglement in creel ropes of pot-based fisheries is amajor cause of mortality in British and Irish waters, butautopsies on turtles which wash ashore dead have alsorevealed the insidious threat of marine litter. Plastic litter,ingested mistakenly for jellyfish which is their main prey,can cause gut blockage and death by starvation.

Detection

● Entanglements occur as isolated eventsscattered over wide areas

● Entangling debris is not easily seen on liveanimals at sea because animals may be onlypartially visible at great distances

● Dead animals are difficult to see because theyfloat just beneath the surface and may beconcealed within debris masses

● Dead entangled animals may disappearquickly because of sinking or predation

Sampling and reporting biases

● Virtually no direct, systematic at-sea sampling has beendone and there have been few long-term surveys

● Sampling methodologies are inconsistent

● Stranding represents an unknown portion of totalentanglements

● Shore counts of live entangled animals are biasedtowards entanglement of survivors carrying small debris

● Entangled animals spend less time ashore and more timeforaging at sea

● Some entanglements reflect interactions with active ratherthan derelict fishing gear

● Many entanglement records may remain unpublished orare anecdotal and cannot be compared geographicallyor temporally

● Few data are available prior to1990

Table 11.1 Factors complicating the analysis of marine entanglement recordsLaist, 1997

Leatherback turtle off Shetland.J.Tulloch

Plastic bags from the stomach of a leatherback turtle, with model forscale.D. Donnan

Dead leatherback turtle.B.Reid/SAC Vet Services


Plastic polymers are commonly transported in theform of pellets, a few millimetres in diameter.Substantial quantities of these pellets enter thesea in industrial effluent, stormwater dischargesor by loss or dumping from shipping. In 1992,plastic pellets were reported to account for 94%of all man-made debris in harbours alongAmerican coasts. To seabirds, fish and turtles thepellets resemble fish eggs and are readily ingested.In the North Sea, northern fulmars have beenidentified as being particularly at risk fromingestion of plastic, because plastic particles canaccumulate in the gizzard of this species (NorthSea Task Force, 1993). Plastic and rubber formedthe greater part of ingested man-made itemsfound in the stomachs of 42 out of 315 Atlanticpuffins from the North Sea (Harris and Wanless,1994).

Recent research has suggested that these pellets(and probably larger plastic objects) mayconstitute a major source of chemical poisoning(Ananthaswamy, 2001; Mato et al., 2001). Studieshave shown that they can adsorb two types oftoxic chemical, PCBs and DDE (a chemicalclosely related to DDT), in quantities of up to amillion times greater than the surroundingseawater. Both of these chemicals are implicatedin immunity and fertility damage to marineorganisms. In addition, in Japan the pellets havebeen found to contain a hormone-disruptingchemical, nonylphenol, at 100 times theconcentration of local sediments.

Sources of dataInformation relating to marine litter is not widelyavailable, with only two sources relevant to aScottish perspective. The MCS Beachwatchinitiative has organised an annual collection andrecording of debris from a number of beachesaround the UK since 1993. This event, mobilisinga largely volunteer workforce, is timed to coincidewith the International Coastal Clean-up scheme,which takes place in 75 countries world-wide. Theresults are published annually in the MCSBeachwatch Nationwide Beach Clean and SurveyReport. Eight major categories of beach litterhave been established according to material type(cloth, glass, metal, paper, plastics, polystyrene,rubber and wood), the majority of which areused as standard categories for world-wide annuallitter surveys. An additional category, sewage-related debris (SRD), has been incorporated intoBritish beach surveys, and items falling into thiscategory may incorporate multiple materials,notably plastic, cloth and rubber. The annualMCS reports currently concentrate on theprobable source of the litter items, withcategories that include tourist/visitor, fishing,

shipping, fly-tipping, SRD and non-sourcedmaterial.

Recently, a more localised appraisal of the litterproblem in the west of Scotland was carried outby the Minch Project, a partnership consisting ofComhairle nan Eilean Siar, Highland Council,SNH, the Scottish Tourist Board and five localenterprise companies (Minch Project, 1997).

The present inability to draw robust conclusionsregarding marine litter trends underlines the needfor refinements to existing data collectionstrategies. The repeated surveying of specificbeaches (widely distributed throughout Scotland)with consistent beach lengths (or area) andassessed at a standard tide level would go someway to increasing confidence and improving dataclarity. Additional information regarding windspeed and direction prior to litter collectionwould also aid interpretation and comparisons ofannual data.

Northern fulmar (Fulmarus glacialis).L. Campbell


ReferencesAnanthaswamy, A. (2001). Junk food. A diet ofplastic pellets plays havoc with animals’ immunity.New Scientist, 20 January, p. 18.

Barnes, D. K. A. (2002). Invasions by marine lifeon plastic debris. Nature 416: 808–809.

Galgani, F., Leaute, J. P., Moguedet, P., Souplet,A., Verin, Y., Carpentier, A., Goraguer, H.,Latrouite, D., Andral, B., Cadiou, Y., Mahe, J. C.,Poulard, J. C. and Nerisson, P. (2000). Litter on thesea floor along European coasts. Marine PollutionBulletin 40: 516–527.

GESAMP (IMO/FAO/UNESCO-IOC/WMO/WHO/IAEA/UN/UNEP Joint Groupof Experts on the Scientific Aspects of MarineEnvironmental Protection) and Advisory Committeeon Protection of the Sea. (2001). Protecting theOceans from Land-based Activities – Land-basedSources and Activities Affecting the Quality andUses of the Marine, Coastal and AssociatedFreshwater Environment. UNEP, Reports andStudies, GESAMP No. 71. GESAMP, The Hague.

Hall, K. (2000). Impacts of Marine Debris and Oil.Economic and Social Costs to CoastalCommunities. KIMO, Lerwick, Shetland.

Harris, M. P. and Wanless, S. (1994). Ingestedelastic and other artefacts found in puffins in Britainover a 24-year period. Marine Pollution Bulletin28: 54–55.

Laist, D. (1997). Impacts of marine debris:entanglement of marine life in marine debrisincluding a comprehensive list of species withentanglement and ingestion records. In: MarineDebris: Sources, Impacts and Solutions. Coe, J.and Rogers, D. B. (eds), pp. 99–119. SpringerVerlag, New York.

Horsman, P. V. (1982). The amount or garbagepollution from merchant ships. Marine PollutionBulletin 13: 167–169.

Marine Conservation Society. (2001). Beachwatch2000. Nationwide Beach Clean and SurveyReport. Marine Conservation Society, Ross-on Wye.

Mato, Y., Isobe, T., Takada, H., Ohtake, C. andKaminuma, T. (2001). Plastic resin pellets as atransport medium for toxic chemicals in the marineenvironment. Environmental Science andTechnology 35: 318–324.

Minch Project. (1997). Marine Litter in the Minch.A report produced for the Minch Project.

North Sea Task Force. (1993). North Sea QualityStatus Report 1993. Oslo and Paris Commissions,London, and Olsen & Olsen, Fredensborg,Denmark.

OSPAR Commission. (2000a). Quality StatusReport 2000. OSPAR Commission, London.

OSPAR Commission. (2000b). Quality StatusReport 2000, Region III – Celtic Seas. OSPARCommission, London.

Velander, K. A. and Mocogni, M. (1998). Marinelitter and sewage contamination at Cramondbeach, Edinburgh – a comparative study. MarinePollution Bulletin 36: 385–389.

Williams, A. T. and Tudor, D. T. (2001). Litterburial and exhumation: spatial and temporaldistribution on a cobble pocket beach. MarinePollution Bulletin 42: 1031–1039.

Williams, A. T., Simmons, S. L. and Fricker, A.(1993). Offshore sinks of marine litter: a newproblem. Marine Pollution Bulletin 26: 404–405.


Non-native species 12

IntroductionThe effects of introduced species on their hostenvironment can include competition with nativespecies for food and space, habitat alteration, changesin water quality, alteration of the gene pool throughhybridisation, predation and the transmission of diseaseor parasites (Rosenthal, 1980; Kohler and Courtenay,1986; Eno et al., 1997). In general, detrimental effectstend to outweigh possible benefits and may bring aboutreduced species diversity. Over the past 400 years, moreglobal extinctions have been attributed to introducedspecies than to any other single factor (WorldConservation Monitoring Centre, 1992). Currently,nearly 20% of vertebrate species at risk of globalextinction are threatened by introduced species(McNeely, 1995). While assessments have relatedpredominantly to terrestrial and freshwaterenvironments, the issues apply equally in the marineenvironment.

A review of non-native species in British watersidentified 51 non-native species (Eno et al., 1997). Anon-native species was defined as a species which:a) has been introduced directly or indirectly(deliberately or otherwise) to an area where it has notoccurred in historical times (within a 5000 year time-frame); b) is separate from and lies outside the areawhere natural range extension could be expected; c) hasbecome established in the wild and has self-maintainingpopulations; and d) includes hybrid taxa derived fromsuch introductions.

TrendsOf 24 non-native species which have been identified inScottish waters, twelve are algae (three diatoms), one ananemone, one a polychaete worm, five are crustaceans(including two barnacles), four are molluscs and one isa sea squirt (Table 12.1). Many are reported to havespread rapidly in Scottish waters, some becomingestablished over large areas. Reported sightings, for 12of them are available on the MNCR database, givingsome indication of distribution. (Box 12.1).

Since the 1997 review (Eno et al., 1997), a newintroduction to the UK, the amphipod Caprella mutica,has been recorded at a salmon farm near Oban (Box12.2). In February 2004, the Japanese seaweed Sargassum

muticum was found in Loch Ryan (Table 12.1).

This chapter was prepared with the assistanceof Catriona Burns.


Asparagopsis armata, a red alga

Codium fragile subsp. tomentosoides (green seafingers), a green alga

Codium fragile subsp. atlanticum (green seafingers), a green alga

Colpomenia peregrina (oyster thief), a brown algaAntithamnionella spirographidis, a red alga

Bonnemaisonia hamifera, a red alga

Box 12.1 Occurrence of 12non-native marine speciesin ScotlandSource: MNCR Database


Styela clava (leathery sea squirt), an ascidianMya arenaria (soft-shelled clam), a mollusc

Potamopyrgus antipodarum (Jenkins spire shell), amollusc

Corophium sextonae, an amphipod (crustacean)

Elminius modestus, a barnacle (crustacean)Haliplanella lineata (orange-striped sea anemone),a sea anemone


Box: 12.2Caprella mutica

Caprella mutica, or skeleton shrimp, wasrecently identified off the west coast of Scotland(Cook et al., 2003). Little is known about it, butrelated species are known to feed on a varietyof microscopic marine animals. It has beenreported from the Pacific coast of North America(Cohen and Carlton, 1995) to European coastalareas including the Netherlands (Platvoet et al.,1995), Norway and southern England.

A project has been proposed by the ScottishAssociation for Marine Science([email protected]/coastal/caprellid) to investigate its biology and ecology,geographic origin and mode of invasion. Theinvestigation of its likely impact on nativespecies, its distribution and patterns of dispersal,would be a case study of the consequences ofnon-native species introduction.

Issues and Implications:Large expanses of water provide a natural barrierto the spread of marine species between landmasses. Temperature and substratumcharacteristics can limit the spread of benthicspecies. Barriers can, however, be breached.Unintentional introduction associated withmariculture as well as deliberate commercialintroduction are known pathways, but it is thefouling of ships’ hulls and, especially, ballastwater which account for the greatest proportionof introductions (Carlton 1992 a & b). Whereasanti-fouling treatments limit the opportunities for

species introductions from ship hulls, thehistorical use of solid ballast has been replaced bywater. Upstream ports in which salinity levels arediluted by freshwater inflows have given way tolarge, deepwater ports on the coast. There,conditions are more favourable to the survival ofnon-native marine species in ballast waterdischarge.

Of 24 non-native marine species found inScottish waters (Table 12.1), ten have potentiallyharmful effects on the environment and/or oncommercial interests (Eno et al., 1997). They arePolysiphonia harveyi, Colpomenia peregrina, Sargassum

muticum, Codium fragile subsp. tomentosoides andsubsp atlanticum, Marenzelleria viridis, Balanus

amphitrite, Elminius modestus, Crassostrea gigas andStyela clava. Their effects include the displacementof native species, competition with native speciesfor food and space, disruption of commercialoyster beds and the fouling of ships, buoys andharbour structures.

The direct effects of non-native species on themarine environment in British waters has, ingeneral, not been as detrimental as those reportedfrom elsewhere in the world (Eno et al., 1997).Control measures have been employed withvarying success on a number of nuisance species,such as the leathery sea squirt (Styela clava) andslipper limpet (Crepidula fornicata), but none havebeen entirely eradicated. Many non-native speciesfail to become established and die out naturally.Site-related factors, such as the closure of apower station, have brought about localextinctions.

Skeleton shrimp (Caprella mutica).T. Nickell/SAMS

Japanese seaweed (Sargassum muticum) in Loch Ryan.G. Saunders


Species

Thalassiosirapunctigera (syn:Thalassiosiraangstii)

Thalassiosiratealata

Odontella sinesis(syn: Biddulphiasinensis)

Asparagopsisarmata (syn:Falkenbergiarufolanosa – partof life cycle)

Bonnemaisoniahamifera (syn:Trailliella intricata– part of life cycle)

Common Nameand Group

None (diatom)

None (diatom)

None (diatom)

Harpoon weed(red alga)

None (red alga)

Date ofintroductionand origin

First detected inPlymouth, Devonin 1978. Originsunknown. Hasbeen recorded inNorth Pacific andSouth Atlantic.

First detectedBlakeney,Gloucestershire in1950. Originsunknown. Hasbeen found inJapanese waters.

Detected inEuropean watersin 1889; firstnoted in Britishwaters 1906.Recorded fromChina Sea butprobablyintroduced fromRed Sea or IndianOcean.

First recorded onLundy in 1949 asFalkenbergiaphase.Asparagopsisphase firstreported fromCornwall in 1950.Introduced frommainland Europe.Originates fromAustralia or NewZealand.

Bonnemaisoniafirst recordedFalmouth,Cornwall andStudland, Dorsetin 1893. Trailliellaphase firstcollected fromDorset in 1890.Originates fromthe Pacific andprobablyintroduced fromJapan.

Method ofintroduction

Unknown. Possiblyballast water orimported oysters.

Unknown. Possiblyballast water orimported oysters.

Suspected ballasttransport.

Possiblyintroduced toEurope withimported oysters,subsequentlyintroduced toBritain by raftingand floating.

Unknown, butconsidered tohave beenintroducedunintentionallywith shellfish.

Rate of spread

English waters andHeligoland in1978; Norway1979;Netherlands1981.

English waters1950; Norway1968.

Has spreadrapidly to becomewidely distributedin throughoutEuropean watersin less than 10years.

Ireland 1939;Lundy 1949;Plymouth 1950;Start Point, S.Devon 1953;Solent 1973;Shetland 1973.

Cornwall 1893;Orkney Islands1929; Shetland1949.

Distribution

English Channeland North Sea.

English Channel toNorway.

Considered to bean importantconstituent of thewinter and springdiatom floraaround Britain.

Distributedthroughout theBritish Isles, butuncommon on eastcoast.

Distributedthroughout BritishIsles, althoughuncommon on eastcoast.

Table 12.1Non-native species in Scottish WatersSources: Eno et al., 1997; T. McCollin, Fisheries Research Services, Personal Communication


Species Common Nameand Group



Rate of spread Distribution

Antithamnionellaspirographidis(syn: Antithamnionspirographidis,Antithamniontenuissimum)

Antithamnionellaternifolia (syn:Antithamnionellasarniensis,Antithamnionsarniensis)

Polysiphoniaharveyi (syn:Polysiphoniainsidiosa)

Colpomeniaperegrina (syn:Colpomeniasinuosa var.peregrina)

Sargassummuticum

South coast ofEngland. southand west coasts ofWales, Irelandand west coast ofScotland.

South and westcoasts of Britain asfar north asStrathclyde inScotland.

South and eastcoasts of England,and up the westcoast to Scotland.

Throughout Britain,with largerpopulation on thewest coast.

Isles of Scilly,entire EnglishChannel coast,east coast north toSuffolk. Welshcoast andStrangford Lough.The first Scottishrecord of attachedplants wasreported from LochRyan in February2004. Route ofintroduction as yetunknown.

Spread rapidly byshipping activities.

Spread rapidlyaround the coastof Britain, fromPlymouth towestern Ireland in30 years, mainlyby shippingactivity.

Rate of spread notknown, althoughmay have spreadthrough driftingwith larger weedson which it is anepiphyte.

England 1907;Isle of Man 1923;Outer Hebrides1936; Orkneys1940.

Spread rapidlyalong the Englishsouth coast atabout 30km/year, usuallyby drifting asfertile adults.Movement wasslowed byconditions ofexposed coasts ofsouth-westEngland, butattached plantswere found inStrangford Lough,Northern Irelandin 1995 andPembrokeshire,Wales in 1997.

Probablytransported onhulls and mooringropes of ships,although couldalso have beenintroduced withoysters.

Probablytransported onhulls and mooringropes of ships.

Introducedunintentionallywith oysters.

Introduced withjuvenile Americanoysters.

Introduced toFranceunintentionallywith thecommercialmovement ofoysters fromCanada or Japan.

Introduced toEurope prior to1911. Firstrecorded fromPlymouth docks in1934. Introducedto Britain from theMediterranean.Thought to haveoriginated in theNorth Pacific.

First recorded in1906 fromPlymouth.Introduced fromthe southernhemisphere(possiblyAustralia).

Introduced before1908 onto thesouth coast ofEngland, possiblyfrom northernFrance. May haveoriginated in thePacific Ocean,being introducedfrom Japan.

Introduced fromFrance intoCornwall andDorset in 1907.Occurs naturally inthe Pacific Oceanand wasintroduced fromthe Pacific coast ofNorth America.

First attached plantrecorded in theIsle of Wight in1971 afterarriving fromFrance.

None (red alga)

None (red alga)

None (red alga)

Oyster thief(brown alga)

Jap weed, wireweed, strangleweed






Codium fragilesubsp. atlanticum

Codium fragilesubsp.tomentosoides

Haliplanellalineata (syn:Haliplanellaluciae)

Marenzelleriaviridis (syn:Scolecolepsisviridis,Scolecolepidesviridis)

Elminius modestus

Found from Dorsetup the west coastof Britain,Shetland and ineast Scotland andNorthumberland.More common innorthern Britain.

Distributedthroughout Britain,but particularlyalong the southcoast of Englandand the west coastof Scotland.

Distributed aroundBritain, generallyoccurring inestuaries, portsand harbours onmajor shippingroutes.

Firth of Forth, Tayand HumberEstuary. Alsofound in estuarieson the Europeanside of the NorthSea and in theBaltic.

Distributed aroundthe Britishmainland coast,but has also beenreported from theHebrides.

Spread the lengthof Britain ,includingShetland, since1840. Spreadfrom Berwick-on-Tweed to St.Andrews between1949 and 1955.

Holland 1900;England 1939;Scotlandsubsequently.

Rate of spreadunknown.


Rapid spread;ChichesterHarbour toShetland in 38years.

Introduced toIrelandunintentionallywith shellfish.

Spread either asan unintentionalintroductionattached toshellfish such asoysters; attachedto ships’ hulls oras spores inballast tanks.Possibly also byrafting andfloating.

Probably carriedon ships hulls andtransported onoysters and othershellfish.

Probablytransported aslarvae of adults inballast water.

Transported onships hulls, orpossibly flyingboats and inballast water.

Recorded in south-west Irelandaround 1808,from where it mayhave spreadthrough rafting orfloating. Found onthe west coast ofScotland before1840. Consideredto have originatedin the PacificOcean, possiblyJapan.

Introduced frommainland Europeto Devon in 1939.Originated in thePacific Oceanaround Japan.

Probablyintroduced to theAtlantic fromJapan towards theend of the 19thCentury.

Recorded in theFirth of Forth in1982 and theFirth of Tay in1984. Occursnaturally on theeast coast ofNorth America.

First recorded inChichesterHarbour,Hampshire in1945 and isbelieved hovehave arrivedbetween 1940and 1943. Naturally occurs inAustralasia andwas introducedfrom Australia ofNew Zealand.

Green sea fingers(green alga)

Green sea fingers(green alga)

Orange-stripedsea anemone(anemone)

None (polychaeteworm)

None (barnacle)






Balanus amphitrite

Acartia tonsa

Corophiumsextonae

Caprella mutica

Potamopyrgusantipodarum (syn:Hydrobia jenkinsi,Pomatopyrgusjenkinsi)

Aulacomya ater

Has been found insouthern England,southern Walesand has also beenrecorded fromShetland in 1988.

Has been found inSouthamptonwater, TamarEstuary, ExeEstuary and theFirth of Forth.

Found in thesouthern andwestern BritishIsles north toScotland.

Recorded in 2003from a salmonfarm near Oban.

Found in salinelagoons andbrackish waterditches aroundBritain. Distributionextends fromShetland to theIsles of Scilly.Generallyconfined to coastalareas in Scotland.

It has only beenfound in theMoray Firth inScotland in 1994and again in1997; no otherEuropeanpopulations areknown.





Rate of spreadmoderate initially,but became morerapid aftercolonisingfreshwater habitatsaround 1904.


Transported onships hulls, orpossibly as thelarval form inballast water.

Possiblyintroduced bytransport on shipshulls or in ballastwaters.

Route ofintroduction notknown.

Introduced to aScottish salmonfarm. Known to bepresent at othersites owned by thesame company.Originallydescribed fromJapanese waters.

Introduced indrinking-waterbarrels used byvessels fromAustralia. Anability to survivebrackish waterprobably aidedpersistence inestuarineconditions.

It is most likely tohave beenintroduced on shipor barge hulls as afouling organism.

Recorded inShorehamHarbour, Sussexin 1937.Considered to benative to the south-western Pacificand IndianOceans.

First recorded inSouthamptonwater between1916 and 1956.Previously knownfrom westernAtlantic and Indo-Pacific.

Introduced intoPlymouth, Devonin the 1930s fromNew Zealand,where it occursnaturally.

First reported in2003.

Probablyintroduced asearly as 1859and was identifiedfrom the ThamesEstuary.Originates fromNew Zealand,and wasintroduced toAustralia.

First found in1994 in theMoray Firth, north-east Scotland,where it wasintroduced fromSouth America.This speciesoriginates on thecoasts of Peru,Chile and theFalkland Islandsand Argentina.

None (barnacle)

None (calanoidcopepod)

None (amphipod)

None (caprellidamphipod)

Jenkins spire shell(mollusc)

Magellan mussel






Crassostrea gigas(syn: Crassostreaangulata)

Mya arenaria

Styela clava (syn: Styelamammiculata)

DistributedthroughoutEngland Scotlandand Wales.

Found on allBritish and Irishcoasts.

South and westcoast of Englandas far north asCumbria. Presentin Loch Ryan andother scatteredScottish localities.

Spread byplacement ofhatchery-producedseed, althoughthere is someevidence tosuggest the someconditions mayallow the transferof larvae overconsiderabledistances.

Spread by naturaldispersal oflarvae.

Spread rapidly.Plymouth 1953;SouthamptonWater 1959;south-west Walesand across theChannel to Franceby 1968. Ireland1972. Found onoysters in LochRyan in in 1987.

Deliberatecommercialintroduction.

May have beendeliberatelyintroduced forfood or bait, oraccidentallytransported in thebilge of shipping.

Transported on thehulls of warshipsfollowing the endof the Korean war.

Introduced fromPortugal into theRiver Blackwaterin Essex in 1926.Occurs naturallyin Japan andsouth-east Asia.

Thought to havebeen introducedfrom the Americancoast during the16th or 17thcentury.

Probablyintroduced in1952. Found inPlymouth, Devonin 1953.Introduced fromthe north-westernpacific.

Pacific oyster, Portuguese oyster(mollusc)

Soft-shelled clam,soft clam, long-necked clam(mollusc)

Leathery sea squirt(ascidian)


ReferencesCarlton, J.T. (1992a). Overview of issuesconcerning marine species introductions andtransfers. In: Proceedings of the conference andworkshop on introductions and transfers of marinespecies: achieving a balance between economicdevelopment and resource protection, Hilton HeadIsland, South Carolina October 30 - November 2,1991. M.R. De Voe (ed.), pp. 65-67. SouthCarolina Sea Grant Consortium.Carlton, J.T. (1992b). Marine species introductionsby ships' ballast water: an overview. In:Proceedings of the conference and workshop onintroductions and transfers of marine species:achieving a balance between economicdevelopment and resource protection, Hilton HeadIsland, South Carolina October 30 - November 2,1991. M.R. De Voe (ed.), pp. 23-25. SouthCarolina Sea Grant Consortium.Cohen, A.N. and Carlton, J.T. (1995).Nonindigenous Aquatic Species in a United StatesEstuary: A Case Study of the Biological Invasions ofthe San Francisco Bay and Delta. A Report for theUnited States Fish and Wildlife Service,Washington, D.C. and The National Sea GrantCollege Program Connecticut Sea Grant Program.272 pp.Cook, L., Willis, K., and Lozano, M. (2003). AlienInvasion: a new non-native invasive species on thewest coast of Scotland. In: Scottish Association ofMarine Science Newsletter 28: 12.

Eno, N.C., Clark, R.A. and Sanderson, W.G.(eds). (1997). Non-Native Marine Species inBritish Waters: a Review and Directory. JointNature Conservation Committee, Peterborough.Gibbs, P.E., Spencer, B.E., and Pascoe, P.L.(1991). The American oyster drill Urosalpinxcinerea (Gastropoda): evidence of decline in animposex-affected population (R. Blackwater, Essex).Journal of the Marine Biological Association of theUnited Kingdom 71: 827-838.Kohler, C.C. and Courtenay, W.R. (1986).American Fisheries Society position onintroductions of aquatic species. Fisheries 11: 39-43.McNeely, J.A., Gadgil, M., Leveque, C., Padoch,C. and Redford, K. (1995). Human influences onbiodiversity. In Global Biodiversity Assessment,V.H. Heywood and R.T. Watson (eds). Cambridge:UNEP, pp. 711–821.Platvoet, D., de Bruyne, R.H. and Gmelig Meyling,A.W. (1995). Description of a new Caprella-species from the Netherlands: Caprella macho nov.spec. (Crustacea, Amphipoda, Caprellidae).Bulletin Zoölogisch Museum, Universiteit vanAmsterdam 15: 1-4.Rosenthal, H. (1980). Implications oftransplantations to aquaculture and ecosystems.Marine Fisheries Review 42: 1-14.World Conservation Monitoring Centre. (1992).Global Biodiversity: Status of the Earth’s LivingResources. London: Chapman & Hall.


Environmental change13

IntroductionThe issues of global warming and sea-level risecontinue to be the focus of much internationalconcern and debate. The interactions betweenclimate, ocean currents and sea temperature arecomplex on both global and local scales.Although some Scottish records for wind speed,tidal height and sea and air temperature extendback over 100 years, they commonly exhibit ahigh degree of short- and long-term variability,making the evaluation of overall trends difficultand subject to regular revisions. The conclusionspresented here are taken from Fisheries ResearchServices (2000), Dawson et al. (2001) and Hulmeet al. (2002).

Trends

Sea-level changeGlobal-average sea level rose by about 1.5 mmper year during the 20th century. This is believedto be due to a range of factors, including thermalexpansion of warming ocean waters and themelting of land glaciers (Hulme et al., 2002). Theaverage rate of mean sea-level rise around theUK during the last century, based on long-termtide gauge records, has been approximately 1 mmper year (Woodworth et al., 1999). All Scottishmainland tide gauges have recorded a sea-levelrise over this period (Dawson et al., 2001). Thelongest time-series from a gauge, installed atAberdeen, indicates an average rise of 0.6 mmper year since 1862 (Figure 13.1). In contrast, atide gauge in Lerwick, Shetland, has recorded afall in sea level since 1957.

The position of sea level at any coast dependsnot only on changes taking place to the sea, butalso on long-term changes taking place within theland mass (Box 13.1). Along most of Scotland’scoast, measurements from tide gauges suggestthat relative sea levels are rising.

StorminessAn increase in storminess has been detected inthe north-east Atlantic over the last 30 years, withan associated increase in significant wave heightof 2.5–7.0 mm per year (Figure 13.4).

Sea temperature changeFisheries Research Services (2000) reports thatScottish coastal waters warmed between 1980 and1998, with summer temperatures increasing atabout 0.5°C every 10 years and wintertemperatures by 1°C. Correspondingly, theaverage range of temperatures from summer towinter narrowed by about 0.5°C. In 1999,however, overall water temperatures were coolerthan the previous year. Dawson et al. (2001)observed that between 1977 and 1997 there was apattern of short-term temperature rise with arange between 0.05 and 0.12°C per year, butwhen placed in context with records from thepast 100 years there is no clear trend.

Wave-scoured coast.L. Gill/SNH


Box 13.1 Rebound relative to rising sea levels

Estimates of sea-level change are modified by a simultaneousrise in the Scottish land mass, which is still undergoing arebounding process following the melting of the overlaying icesheet some 10,000 years ago at the end of the last ice age.

The rate of rebound is greatest in mainland areas, where the icelayer was thickest. Offshore areas, such as the Northern Islesand the Outer Hebrides, were under thinner ice and so theextent of rise is correspondingly smaller and may even amount toa relative sinking (Shennan, 1989).

In areas where rebound is greatest, the rate of land upliftexceeds the rise in mean sea level, resulting in falling sea levelsrelative to the land. Estimates of current and future sea levelchange for Scotland, adjusted to take account of upliftmovements, are shown in Figures 13.2 and 13.3.

Most of the tide gauges in Scotland lie outside the area ofgreatest uplift and record rising mean sea level.

Figure 13.1 Changes in annual relative sea level (mm scale) recorded by tidegauges at five locations around the UK coastline. Data areunadjusted for natural land movements. The scale represents 100-mm graduations.Reproduced from Hulme et al., 2002, with permission from UKCIP.

Figure 13.2 Present rates of relative sea-level change in Scotland Source: Dawson et al., 2001.

Figure 13.3 Best estimate of sea-level rise for 2050 AD.


Marine plankton has been proposed as abiological indicator of environmental change,being responsive to the combined effects oftemperature and ocean currents (Box 13.2).

Copepods, small shrimp-like crustaceans, form an importantpart of the diet of some fish and so provide an integratedmeasure of ocean biological production in waters aroundScotland. Able to multiply rapidly, populations fluctuatereadily in response to changing environmental conditionsand modifications due to the management of the seas.According to the Sir Alister Hardy Foundation for OceanScience (SAHFOS) web site, they are ideally suited tomonitoring environmental change.

Since the 1930s, marine plankton abundance has beenmeasured in the North Atlantic and North Sea by towing acontinuous plankton recorder behind commercial shippingon defined routes. From this record, two specificzooplankton indicators have been selected for reporting bySAHFOS:

Box 13.2 Marine plankton – indicators ofenvironmental changeSource: The Sir Alister Hardy Foundation for Ocean Science (www.sahfos.org))

● the total annual abundance of copepods in the NorthSea; and

● the abundance, in the northern North Sea, of a thecold–temperate water copepod species, Calanusfinmarchicus, a dominant copepod in the sea and animportant part of the food chain betweenphytoplankton- and zooplankton-eating fish.

Two key relationships have been identified:

● More copepods are present when the Gulf Streamfollows a northerly path. The Gulf Stream PositionIndex, measured since 1966, is the position of thenorth wall of the Gulf Stream. Total annual abundanceof copepods in the North Sea has varied greatly butpeaks have tended to be associated with a morenortherly Gulf Stream position and the timing of theonset of spring stratification – the formation of awarmer surface layer in the sea.

● In contrast, between 1958 and 1995, a markeddecline in populations of Calanus finmarchicus in theNorth Sea has been associated with a trend towardsstronger westerly air flows over the Atlantic in winter.The westerly air flow is linked to higher values of theNorth Atlantic Oscillation – the difference inatmospheric pressure between the south and north inthe North Atlantic. The decline of Calanusfinmarchicus may be the result of changes inoverwintering habitat, food supply and/or warmertemperatures in the North Sea.

According to SAHFOS, a continued northward shift ofthe Gulf Stream could bring about increasing copepodnumbers in the North Sea. However, the negativerelationship between Calanus finmarchicus populationsand the North Atlantic Oscillation suggests that not allspecies will benefit.

The long-term response of the Gulf Stream to globalwarming remains uncertain.

Figure 13.4 The percentage increase in the significant wave height (i.e. theaverage height of the highest third of the waves) in the NorthAtlantic in winter (December–February) between the periods1985–1989 and 1991–1996. Note the short periods over whichdata are averagedSource: JERICHO, (1999). Reproduced from Hulme et al., 2002,with permission from UKCIP.

Continuous plankton recorder.SAHFOS


Issues and implicationsThe projected effects of climate change aresubject to regular revisions as more data areincluded and modelling scenarios become evermore sophisticated. Predictions continue to behampered, however, by uncertainties in both theunderlying scientific theory and levels ofgreenhouse gas emissions.

A rise in sea level globally is considered to bevery likely over the medium term, most probablyat rates exceeding those of the twentieth century.Recent reports suggest that heating of the oceansurface caused by enhancement of thegreenhouse effect will be transferred to thecooler deep waters, leading to a substantialvolume expansion. This is predicted to initiate anaverage global sea-level rise of around 6–7 cm by 2020 (Hulme et al., 2002). In Scotland, allcoastal areas are likely to experience a relative sea-level rise in the 21st century, including thosewhich have experienced a fall in relative sea levelsto date.

Much of Scotland’s coast is steep and rocky. Theconsequences of a rising sea level will be felt

Figure 13.5 Change in 50-year return period surge height (metres) for the2080s for three different scenarios. The combined effect of global-average sea-level rise, storminess changes and vertical landmovements (from Shennan, 1989) are considered. (a) Low-emissions scenario (low sea-level rise estimate: 9 cm). (b) Medium- to high-emissions scenario (central estimate:

30 cm). (c) High-emissions scenario (high estimate: 69 cm).Reproduced from Hulme et al., 2002, with permission from UKCIP.

MarClim: the impact of climatechange on subtidal and intertidalbenthic species in Scotland.


most severely on low-lying coasts, and especiallywhere prevailing winds tend to generate stormsurges. Safeguarding property, infrastructure andproduction will be dominant concerns. Thediscussion here relates to natural heritageconsequences.

In areas protected by flood defences, rising sealevel is liable to result in the modification and lossof intertidal areas through ‘coastal squeeze’,whereby the low-water line migrates landward butthe high-water line can only rise up the defensivewall. In low-lying unprotected areas, the coast willtend to be pushed inland. In both cases, it isextreme events such as storm surges and largewaves that will cause most damage (Figure 13.5).A summary of the most recent predictions isgiven in Table 13.1.

Enclosed areas of sea bed, such as in sea lochs,may experience greater seasonal impacts fromdeoxygenation due to increased thermalstratification, or temperature layering. Thisinhibits the distribution of oxygen throughoutthe water column and thus depletes its availabilityat the sea bed.

Evidence to support temperature-mediatedadjustments of species ranges has recentlyemerged from fish studies in the lower Forthestuary. Regular research trawls in the estuary

Relativeconfidencelevel

H

H

M

H

L

M

L

H

UKCIP02 scenarios

● Will continue to rise for several centuries, andprobably longer

● The West Antarctic ice sheet will contributerelatively little to sea-level rise in the presentcentury

● Will increase by the 2080s by between 9 and69 cm

● Continuation of historic trends in vertical landmovements will introduce significant regionaldifferences in relative sea-level rise around theUK

● Will be similar to the global-average value

● For some coastal locations and some scenariosstorm surge return periods by the 2080s willreduce by an order of magnitude

● Changes in storminess, sea level and landmovement mean that storm surge heights willincrease by the greatest amount off south-eastEngland

● Sea surface temperatures will increase aroundall UK coasts

Variable

Global-average sea level

UK sea-level change

Extreme sea levels

Marine climate

Table 13.1 Summary statementsof the changes insea level and marineclimate for the UKClimate ImpactsProgramme(UKCIP02) climatechange scenarios. Source: Hulme et al.,2002

Relative confidence levels: H = high; M = medium; L = low.

routinely recover around 30 species of fish. Ofthese, the eelpout (Zoarces viviparus) was the mostabundant between 1981 and 1987 (Elliott et al.,1990), but by 2001 had declined to the seventhmost abundant (Greenwood et al., in preparation).A closely correlated pattern of eelpoutabundance decline has also been observed in theNorwegian Kattegat area, and both, in turn, arevery highly correlated with increases in the NorthSea bottom temperature. The eelpout is close tothe southern limit of its range in the Forth, and itis suggested that warmer weather has reducedreproductive success throughout the North Seaand caused a northward shift in eelpoutdistribution (Greenwood et al., in preparation).On the basis of these trends it is speculated thateelpout may become extinct from the Forth in20–40 years, in line with predictions for marinespecies and communities more generally (Box13.3). Moreover, another species, the fatherlasher(Myoxocephalus scorpius), has shown significantabundance increases and may either be extendinginto the niche vacated by the eelpout or simplyincreasing in response to a northerly extension ofits own range.


Ciocalypta penicillusHaliclona angulataGymnangium montaguiEunicella verrucosaAiptasia mutabilisBalanus perforatusMaja squinadoOsilinus lineatusPatella depressaCrepidula fornicataTritonia nilsodheriSolen marginatusPhallusia mammillataScinaia furcellataChondracanthus acicularisStenogramme interruptaLaminaria ochroleucaBifurcaria bifurcataCystoseira baccataCystoseira foeniculaceus

Axinella dissimilisHemimycale columellaPhorbas fictitiusHaliclona cinereaHaliclona fistulosaHaliclona simulansAlcyonium glomeratumAnemonia viridisAulactinia verrucosaCorynactis viridisSabellaria alveolataChthamalus montaguiChthamalus stellatusHippolyte huntiiPalinurus elephasPolybius henslowiEbalia tumefactaCorystes cassivelaunusLiocarcinus arcuatusLiocarcinus corrugatusGoneplax rhomboidesPilumnus hirtellusXantho incisusXantho pilipesTricolia pullusGibbula umbilicalisPatella ulyssiponensisBittium reticulatumCerithiopsis tubercularisMelaraphe neritoidesCalyptraea chinensisClathrus clathrusOcenebra erinaceaActeon tornatilisPleurobranchus membranaceusAtrina fragilis

Crassostrea virginicaCerastoderma glaucumGari depressaPentapora fascialisAsterina gibbosaParacentrotus lividusHolothuria forskaliCentrolabrus exoletusCrenilabrus melopsCtenolabrus rupestrisLabrus mixtusThorogobius ephippiatusScinaia trigonaAsparagopsis armataBonnemaisonia hamiferaNaccaria wiggiiJania rubensLithothamnion corallioidesMesophyllum lichenoidesCalliblepharis ciliataKallymenia reniformisRhodymenia delicatulaRhodymenia holmesiiRhodymenia pseudopalmataHalurus equisetifoliusSphondylothamnion multifidumDrachiella heterocarpaDrachiella spectabilisStilophora tenellaHalopteris filicinaDictyopteris membranaceaTaonia atomariaCarpomitra costataCystoseira tamariscifoliaCodium adhaerensCodium tomentosum

Southern species notcurrently recorded inScotland but whichmay spread toScotland

Northern species whichmay either decrease inabundance and extent ordisappear from Scotland

Southern species currently recorded in Scotlandwhose extent of distribution or abundance mightincrease

Thuiaria thujaSwiftia pallidaBolocera tuediaePhellia gausapataLithodes maiaTonicella marmoreaMargarites helicinusTectura testudinalisOnoba aculeusColus islandicusAkera bullataLimaria hiansAnomia ephippiumThyasira gouldiiLeptometra celticaLeptasterias muelleriSemibalanus balanoidesLithodes maiaStrongylocentotus droebachiensisCucumaria frondosaStyela gelatinosaLumpenus lumpretaeformisZoarces viviparusLithothamnion glacialePhymatolithon calcareumCallophyllis cristataOdonthalia dentataSphacelaria arcticaSphacelaria mirabilisSphacelaria plumosaChorda tomentosaAscophyllum nodosum mackaiiFucus distichus distichusFucus evanescens

Table 13.2 Species with currently restricted distributionsin or near Scotland and predicted effects of asea temperature rise of 1–2˚C Source: Hiscock et al., 2001

Box 13.3 Species impacts

An examination of the possible effects of currently predicted rises in seaand air temperature on the distribution of marine species andcommunities was undertaken by Hiscock et al. (2001). They concludedthat species losses over the next 100 years would be restricted to a smallnumber of northern species currently at their southern limit. Warmingmay increase the diversity of Scottish seabed communities owing to aninflux of a greater number of southern species.A summary of proposed modified species distributions is shown in Table13.2. Some communities that are particularly well developed in Scotlandcould be affected over the longer term, such as those associated withmaerl and Modiolus beds


Sources of data

The Fisheries Research Services produce anirregular report, the Ocean Climate Status Report,outlining trends in the weather and thetemperature of coastal, offshore and oceanicwaters around Scotland. In addition, trends in thewider North Atlantic are examined in the Annual

ICES Ocean Climate Status Summary published byICES.

Other organisations that produce or analyserelevant data are:

● the Tyndall Centre for Climate ChangeResearch;

● the Hadley Centre for Climate Prediction andResearch;

● the UK Climate Impacts Programme;

● the MarClim Project – Marine BiologicalAssessment UK/SAMS.

References

Dawson, A., Smith, D. E. and Dawson, S. (2001).The Potential Impacts of Climate Change on SeaLevels around Scotland. Scottish Natural HeritageResearch Survey and Monitoring Report, No. 178.Scottish Natural Heritage, Edinburgh.

Elliott, M., O’Reilly, M. G. and Taylor, C. J. L.(1990). The Forth estuary: a nursery andoverwintering area for North Sea fishes.Hydrobiologia 195: 89–103.

Fisheries Research Services. (2000). OceanClimate Status Report 1999. Fisheries ResearchServices Report, 06/00. Fisheries ResearchServices, Aberdeen.

Greenwood, M. F. D., Hill, A. S. and McLusky, D.S. (in preparation). Trends in abundance of benthicdemersal fish populations of the lower ForthEstuary, East Scotland, from 1982 to 2001.

Hiscock, K., Southward, A., Tittley, I., Adam, J. andHawkins, S. (2001). The Impact of Climate Changeon Subtidal and Intertidal Benthic Species inScotland. Report to Scottish Natural Heritage fromthe Marine Biological Association of the UK. Phase1: Introduction and species researched. ScottishNatural Heritage Research Survey and MonitoringReport, No. 182. SNH, Edinburgh.

Hulme, M., Jenkins, G. L., Lu, X., Turnpenny, J. R.,Mitchell, T. D., G., Jones, R. G., Lowe, J., Murphy,J. M., Hassall, D., Boorman, P., McDonald, R. andHill, S. (2002). Climate Change Scenarios for theUnited Kingdom: the UKCIP02 scientific report.Tyndall Centre for Climate Change Research,School of Environmental Sciences, University ofEast Anglia, Norwich.

JERICHO. (1999). JERICHO: Joint Evaluation ofRemote Sensing Information for Coastal andHarbour Organisations. Final report. BNSC EarthObservation LINK Programme, UK.

Shennan, I. (1989). Holocene crustal movementsand sea level changes in Great Britain. Journal ofQuaternary Science 4: 77–89.

Woodworth, P. L., Tsimplis, M. N., Flather, R. A.and Shennan, I. (1999). A review of the trendsobserved in British Isles mean sea level datameasured by tide gauges. Geophysical JournalInternational 136: 651–670.

Additional source

ICES. (2001). The Annual ICES Ocean ClimateStatus Summary 2000/2001. ICES Working Groupon Ocean Hydrography Report. Turrell, B. andHolliday, N. P. (eds). ICES, Copenhagen.


ConclusionsPart 5


Conclusions14Scotland’s seas, positioned between subpolar andsubtropical influences, are among the mostbiologically productive in the world. Theysupport a fascinating and diverse assemblage ofmarine habitats and species, provide a wealth ofimportant natural resources and offer abundantopportunities for recreation and enjoyment.

Nevertheless, the seas around Scotland have beensubject to a multitude of pressures. Withoutimproved knowledge, care and long-termcommitment to their protection, they could beirreparably damaged. This audit has sought toidentify and describe ways in which the marineenvironment is changing, and so help to informpolicies and advice. We seek to share thatknowledge so that it can be used by others whohave an interest in the well-being of the seasaround Scotland, and in marine environmentsmore generally.

The SNH Natural Heritage Futures programme(Box 14.1) sets out natural heritage objectives forcoasts and seas. They are examined here, in thelight of audit findings. With a marine ecologyfocus, the audit of the seas around Scotland hasmore to say on some objectives than others. Inparticular, it did not attempt to address coastalissues, landscape or recreation. Coverage of thoseaspects of the maritime environment may beaddressed more fully by future audits.

Box 14.1 Natural HeritageFutures

A suite of publications, called NaturalHeritage Futures, has been prepared byScottish Natural Heritage to guide themanagement of the natural heritagetowards 2025. That on Coasts and Seas(SNH, 2002) examines maritime issueswithin the context of sustainabledevelopment. The Futures programmeseeks to ensure that we take anintegrated approach to our work acrossour whole remit and, at the same time,provide the basis for our engagementwith other stakeholders.

Previous page: Kelp forest (Laminaria hyperborea).D. Donnan

Above: Whale jawbone, North Berwick Law.J. Baxter


Natural Heritage Futures, Coastsand Seas, Objective 1: to improvemanagement, stewardship,awareness and understanding ofmarine ecosystems

The total number of Scottish marine species isestimated to exceed 40,000 (Chapter 1).Knowledge of habitats and species comes from avariety of sources. Dispersed and incomplete assurvey coverage is, it continues to revealspectacular new discoveries, such as coldwatercorals and the sublittoral St Kilda plateau tracingout the remnants of long extinct volcanic activity.

Biodiversity Action Plans have been specified forspecies and habitats that are considered to berepresentative, rare or at risk. Of the 81 marine,estuarine or brackish-water species incorporatedwithin UK Action Plans, 74 are found aroundScottish coasts (Chapter 2).

Two species of seal, the grey and the harbour (orcommon), are present around the coast ofScotland in internationally important numbers(Chapter 5). The status of both is currentlyconsidered to be good, although the full effect onharbour seal numbers of a phocine distempervirus (PDV) outbreak in 2002 remains to be seen.The fishing and fish farm industries haveexpressed concern over increasing seal numbersand research projects are under way at the SeaMammal Research Unit (SMRU) to betterunderstand seal population dynamics and diet.

A probable consequence of climate change(Chapter 13) is that a small number of northernspecies which are currently at the southern limitof their range may disappear from Scotland overthe next 100 years. However, the effect ofwarming is that overall diversity is likely toincrease as a greater number of southern speciesmigrate into and become established in Scottishwaters. There is already some evidence of shiftingdistributions among fish species which are at thelimits of their northerly or southerly ranges in thelower Forth estuary. Some communities that areparticularly well developed in Scotland could beadversely affected over the longer term, such asthose associated with the calcareous seaweed,maerl and horse mussel beds (Modiolus modiolus),both of which are considered to be ofinternational importance in Scottish waters.

Diver and fireworks anemone(Pachycerianthus multiplicatus).G. Saunders


Natural Heritage Futures, Coastsand Seas, Objective 2: to managethe coastline in sympathy withnatural processes

Studies of the Scotland’s eastern coastline haveconcluded that it has become cleaner, morescenic and better managed over the last 30 years(Chapter 2). This has been attributed, in largepart, to the effectiveness of direct conservationmanagement. Throughout Scotland, SSSIcoverage along the coast is well developed.However, similar regard to the protection ofsubtidal areas has occurred only with theapplication of the Habitats Directive in recentyears.

Much of Scotland’s coast is steep and rocky. Theconsequences of a rising sea level will be feltmost severely on low-lying coasts, and especiallywhere prevailing winds tend to generate stormsurges (Chapter 13). On coasts protected by seadefences, the intertidal will be modified andreduced in extent. In low-lying unprotected areas,the coastline will tend to be pushed inland.

Natural Heritage Futures, Coastsand Seas, Objective 3: to safeguardand enhance maritime biodiversityand ecosystems

Few data are available on population trends forthe 22 species of dolphin, porpoise and whalethat occur in Scottish waters (Chapter 4).However, the OSPAR Commission (Oslo andParis Convention for the Prevention of MarinePollution) has reported that most species of largewhale are showing signs of recovery in Europeanwaters following a moratorium by most countrieson commercial whaling. No clear trends areevident for smaller whales, dolphins andporpoises. A steady increase in the number ofstrandings in UK and Irish waters was recordedbetween the 1960s and 1980s. No clear trendshave been evident from Scottish strandingsduring the past decade; their occurrence seemssimply to correspond with the generaldistribution of cetacean species around the coast.

Scotland’s breeding seabird populations areinternationally important (Chapter 6). Trendssometimes vary markedly between Scottishregions, for example between populations in theNorth Sea and Irish Sea/Atlantic Ocean. They

Kiloran Bay, ColonsayL. Gill/SNH

Female cuckoo wrasse(Labrus mixtus). R. Holt


are driven by a wide range of factors, and maydiffer between colonies of the same species.Between around 1970 and 1985, 11 out of 18seabird species showed a marked increase in theirbreeding populations (i.e. by at least 10%), andfour showed a marked decline.

Of 24 non-native marine species found inScottish waters (Chapter 12), ten have potentiallyharmful effects on the environment and/or oncommercial interests. Difficult or impossible toeradicate, the direct effects of non-native specieson the marine environment (such as thedisplacement of native species, competition withnative species for food and space, disruption ofcommercial oyster beds and the fouling of ships,buoys and harbour structures) have not yetproved to be as detrimental as those reportedfrom elsewhere in the world. However, seatemperature rise may in the future give somenon-native species an enhanced competitiveadvantage.

A further consequence of climate change may bethat enclosed areas of sea bed, such as in sealochs, may experience greater seasonal impactsfrom deoxygenation (Chapter 13).

Natural Heritage Futures, Coastsand Seas, Objective 4: to safeguardand enhance the fine scenery anddiverse character of coastalseascapes and landscapes

A comparison of North Sea coastal developmentin 1988 with that of 1999 revealed little change,other than an increase in the relative importanceof leisure and recreational uses (Chapter 2).

Right: Isle of Lewis.L. Gill/SNH

Below: Curled octopus(Eledone cirrhosa).G. Saunders


Natural Heritage Futures, Coastsand Seas, Objective 5: to enhancepopulations of overexploitedcommercial fish species and ensurethat fishing is sustainable

The state of commercially exploited fishpopulations and damage to the sea bed from gearused to catch them raise ecological concerns(Chapter 8). Fishing activity has had an impact onthe north-eastern Atlantic region and may be themain ecological structuring force on the benthosin areas of intense exploitation. An ecosystem-based management approach, based on anintegrated fisheries management policy that takesaccount of ecological community structure andan appreciation of appropriate spatial andtemporal scales, is imperative.

Scottish coastal waters hold at least 18 species ofshark, eight species of ray and three species ofskate (Chapter 3). Over-exploitation has beenimplicated in declines of various species. Fourspecies are now in such a perilous state that theyrequire statutory protection. The two biggest –the common skate and the basking shark – havebeen fished to commercial extinction.

Among 12 commercially exploited deep-waterfish species, five are considered by ICES(International Council for the Exploration of theSea) to be harvested outside safe biological limitsand the status of others is largely unknown(Chapter 9). Deep-water trawling is a threat tohabitats and species found along the Europeancontinental shelf break and slope.

Natural Heritage Futures Coasts andSeas, Objective 6: to ensure thatsalmon farming and other types ofaquaculture are environmentallysustainable

Fish farming in Scotland has grown rapidly sincethe mid-1980s. It has become an importantemployer and revenue-generating industry amongmany of the remoter coastal communities(Chapter 7). Almost all sea lochs with conditionssuitable for mariculture now have at least oneinstallation. However, intensive farming practices,for salmon in particular, have raised ecologicalconcerns about localised impacts on the sea bed,aesthetic degradation of the landscape, nutrientenrichment of coastal waters, predator controlmeasures and interactions with wild Atlanticsalmon populations.

Shellfish farming, reliant simply on naturallyoccurring phytoplankton in the water for food,must represent one of the most sustainableforms of production. However, some planktonspecies that constitute food for shellfish producetoxins which can build up in farmed and wildshellfish. This calls for a better understanding ofthe causes of toxic algal blooms, their frequencyof occurrence and their implications for themarketability of shellfish.

Kirkwall harbour.J.Baxter

Oyster farm.J. Charity/SNH


Natural Heritage Futures, Coastsand Seas, Objective 7: to improvethe water quality of estuaries andseas

Major improvements in water quality, broughtabout by pollution controls, have been reflectedin signs of ecological recovery within the Clydeand Forth estuaries of central Scotland (Chapter10). Problems associated with more diffusepollution remain, such as in the catchment andestuary of the River Ythan. Elsewhere, dogwhelkpopulations that had suffered declines as a resultof formerly high tributyltin (TBT) levels atmonitored locations in the Shetland Isles, theFirth of Clyde and Loch Ryan had mainly re-established by 2001.

The accumulation of litter, on and within theopen sea, upon the sea bed and on the shore, is aproblem (Chapter 11). Unsightly degradationalong the strandline is the most obviousconsequence. More insidious effects tend to gounseen. Drowning and slow starvation arecommon consequences of entanglement in debrisby marine mammals and birds. Plastic pellets,resembling fish eggs, cause chemical poisoning inbirds, fish and turtles. Seabirds and their chicksare susceptible to ingesting litter. Plastic bags cancause gut blockage and death by starvationamong turtles, which mistake them for theirjellyfish prey.

Natural Heritage Futures, Coastsand Seas, Objective 8: to promoteaccess to the sea and coast forpublic enjoyment and recreation

Marine wildlife tourism in Scotland generatedrevenues of some £57 million and providedaround 2,670 full-time jobs in 1996 (Chapter 1).

Forth estuary.J. Baxter

Angling on the Ythan estuary.L.Gill/SNH


Summing up

Looking across the eight objectives for coast andsea, many positive messages are present. Notableamong them is the ability of nature, given time,to recover or re-establish where damage causedby pollution or other impacts is remedied.However, much still needs to be done to bringparts of Scotland’s coastal waters back to a morefavourable state – for health and enjoyment, andfor the restoration of ecosystem functions.

The example of discarded litter around ourshores should serve as an unsightly warning ofunseen damage and distress caused to wildlife. Ithas economic impacts too. There is no reasonwhy a cleaner environment cannot go hand inhand with a prosperous economy and enhanceScotland’s attractiveness as a tourist destinationand business location.

Several fish stocks of the continental shelf and indeep waters to the west are over-exploited. Thebiggest among our fish species have beenreduced to commercial extinction. Trawl damageis now coming to light on the seabed, the lastgreat frontier of exploration and discovery onour planet. We need to develop a betterunderstanding of the characteristics andrequirements of this functioning ecosystem.

The consequences of climate change in themarine environment are becoming evident. Weneed to become more responsive and adaptive tochange.

Opportunities exist to do something positive. Acommitment to find solutions to these majorissues is demonstrated by the Scottish SustainableMarine Environment Initiative, led by theScottish Executive. Similarly, a MarineImplementation Plan is being developed as partof the forthcoming Scottish Biodiversity Strategy.

Novel approaches to sustainable management arerequired. These must be in partnership, takingaccount of nature conservation prioritiesalongside socio-economic needs We need toarrive at a shared vision for the future, in whichhard choices may be required to secure long-termgains.

What this report has shown is that we need to beprepared to learn, understand and re-examine theways in which we interact with the seas aroundScotland.

ReferenceSNH. (2002). Natural Heritage Futures: Coasts and

Seas. Scottish Natural Heritage, Battleby.

Deadman’s fingers (Alcyonium digitatum) and the cushion star (Porania pulvillus)S. Scott/SNH

AppendicesPart 6


Appendix 1: SEPA coastal waters classification schemeCl

ass

A B C D

Des

crip

tion

Exce

llent

Goo

d

Uns

atisf

acto

ry

Serio

usly

pol

lute

d

Use

-rel

ate

ddes

crip

tion

Fit f

or a

ll de

fined

uses

Fit f

or a

ll de

fined

uses

Def

ined

use

s m

aybe

com

prom

ised

by th

e oc

casio

nal

pres

ence

of

sew

age-

deriv

edm

ater

ial o

r by

mod

erat

e or

gani

cen

richm

ent

Def

ined

use

sco

mpr

omise

d or

prev

ente

d by

the

frequ

ent p

rese

nce

of s

ewag

e-de

rived

mat

eria

l or

chem

ical

pol

luta

nts

Aes

thet

icco

nditi

on

Nea

r pris

tine,

unco

ntam

inat

ed

Unp

ollu

ted

but

may

sho

w s

igns

of

cont

amin

atio

n

Occ

asio

nal

obse

rvat

ions

or

subs

tant

iate

dco

mpl

aint

s of

sew

age

solid

s,sm

ell n

uisa

nce

oroi

l

Freq

uent

obse

rvat

ions

or

subs

tant

iate

dco

mpl

aint

s of

sew

age

solid

s,sm

ell n

uisa

nce

oroi

l

and

and

or or

Bio

logic

al

cond

ition

Flor

a an

d fa

una

norm

al

Flor

a an

d fa

una

norm

al

Flor

a an

d/or

faun

a m

odifi

ed b

yef

fluen

t disc

harg

es

Flor

a an

d/or

faun

aim

pove

rishe

d or

abse

nt

and

and

or or

Bact

erio

logic

al

cond

ition

Likel

y to

fail

tom

eet q

ualit

ysta

ndar

ds n

o le

ssstr

inge

nt th

an th

em

anda

tory

stand

ards

for E

C-

desig

nate

dba

thin

g w

ater

s

Likel

y to

freq

uent

lyfa

il to

mee

t qua

lity

stand

ards

no

less

strin

gent

than

the

man

dato

rysta

ndar

ds fo

r EC

-de

signa

ted

bath

ing

wat

ers

Chem

ical

cond

ition

Likel

y to

mee

t all

qual

ity s

tand

ards

appl

ied

as a

cons

eque

nce

ofth

e EC

Dan

gero

usSu

bsta

nces

Dire

ctiv

e

Likel

y to

fail

any

one

or m

ore

ofqu

ality

sta

ndar

dsap

plie

d as

aco

nseq

uenc

e of

the

EC D

ange

rous

Subs

tanc

esD

irect

ive

and

or

Likel

y to

mee

t qua

lity

stand

ards

no

less

stri

ngen

tth

an th

e gu

idel

ine

stand

ards

for E

C-d

esig

nate

dsh

ellfi

sh a

nd b

athi

ng w

ater

s

Likel

y to

mee

t qua

lity

stand

ards

no

less

stri

ngen

tth

an th

e m

anda

tory

sta

ndar

ds fo

r EC

-des

igna

ted

shel

lfish

and

bat

hing

wat

er

Sour

ce: S

aund

ers,

G.,

Dobs

on, J

. and

Edw

ards

, A. (

2002

). Th

e sta

te o

f Sco

tland

’s se

as a

nd e

stuar

ies.

In: T

he S

tate

of S

cotla

nd’s

Envi

ronm

ent a

nd N

atur

al H

erita

ge. U

sher

, M. B

., M

acke

y, E

. C. a

nd C

urra

n, J.

C. (

eds).

The

Sta

tione

ry O

ffice

, Edi

nbur

gh.

Previous page: Papa Stour cSAC,Shetland. J.Baxter


Appendix 2: SEPA estuarine waters classification scheme

Class

A B C D

Des

crip

tion

Exce

llent

Goo

d

Uns

atisf

acto

ry

Serio

usly

pollu

ted

Aes

thet

icco

nditi

ons

Unp

ollu

ted

May

sho

w s

igns

of c

onta

min

atio

n

Occ

asio

nal

obse

rvat

ions

or

subs

tant

iate

dco

mpl

aint

s of

pollu

tion

Freq

uent

obse

rvat

ions

or

subs

tant

iate

dco

mpl

aint

s of

pollu

tion

Fish

mig

ratio

n

Wat

er q

ualit

yal

low

s fre

epa

ssag

e

Wat

er q

ualit

yal

low

s fre

epa

ssag

e

Wat

er q

ualit

yre

stric

ts pa

ssag

e

Wat

er q

ualit

yal

low

s no

pass

age

Res

iden

tbio

ta a

nd/o

rbio

ass

ay

Nor

mal

Nor

mal

Mod

ified

Impo

veris

hed

or s

ever

ely

mod

ified

Res

iden

tfi

sh

Resid

ent f

ishco

mm

unity

norm

al

Resid

ent f

ishco

mm

unity

norm

al

Resid

ent f

ishco

mm

unity

mod

ified

Resid

ent f

ishco

mm

unity

impo

veris

hed

Pers

iste

ntsu

bst

anc

es(b

iota

)

Less

than

twic

ena

tiona

lba

ckgr

ound

Mor

e th

an o

req

ual t

o tw

ice

natio

nal

back

grou

nd b

utle

ss th

ansu

bsta

ntia

llyel

evat

ed

Subs

tant

ially

elev

ated

but

not

gros

sly e

leva

ted

Gro

ssly

ele

vate

d

Sour

ce: S

aund

ers,

G.,

Dobs

on, J

. and

Edw

ards

, A. (

2002

). Th

e sta

te o

f Sco

tland

’s se

as a

nd e

stuar

ies.

In: T

he S

tate

of S

cotla

nd’s

Envi

ronm

ent a

nd N

atur

al H

erita

ge. U

sher

, M. B

., M

acke

y, E

. C. a

nd C

urra

n, J.

C. (

eds).

The

Sta

tione

ry O

ffice

, Edi

nbur

gh.

UK

Red

lis

t and

EC-d

esig

nate

ddang

erou

ssu

bst

anc

es

100%

com

plia

nce

of s

ampl

es w

ithen

viro

nmen

tal

qual

ity s

tand

ards

(EQ

S)

Ann

ual

com

plia

nce

ofsa

mpl

es w

ith E

QS

One

or m

ore

List I

Isu

bsta

nces

fail

toco

mpl

y w

ith E

QS.

List I

and

Red

List

all c

ompl

y

One

or m

ore

List I

or R

ed L

istsu

bsta

nces

fail

toco

mpl

y w

ith E

QS

Dis

solv

edox

ygen

(D

O)

Min

imum

DO

> 6

mg/

l

Min

imum

DO

£ 6

mg/

l but

> 4

mg/

l

Min

imum

DO

£ 4

mg/

l but

> 2

mg/

l

DO

< 2

mg/

l

Wate

r ch

emis

try


Appendix 3: definition of microbiological requirements forguideline and mandatory passes of bathing waters basedon the minimum number of samples (20) that are takenfrom each location

Level of pass

Pass – guideline

Pass – mandatory

Interpretations

Directive states

Based on 20samples

Directive states

Based on 20samples

Total coliforms

80% of samples shouldnot exceed 500 totalcoliforms per 100 ml

At least 16 samples mustcontain 500 or fewertotal coliforms per 100ml

95% of samples shouldnot exceed 10,000 totalcoliforms per 100 ml

Only one sample cancontain more than10,000 total coliformsper 100 ml

Faecal coliforms

80% of samples shouldnot exceed 100 faecalcoliforms per 100 ml

At least 16 samples mustcontain 100 or fewerfaecal coliforms per 100ml

95% of samples shouldnot exceed 2,000 faecalcoliforms per 100 ml

Only one sample cancontain more than 2,000faecal coliforms per 100ml

Faecal streptococci

90% of samples shouldnot exceed 100 faecalstreptococci per 100 ml

At least 18 samples mustcontain 100 or fewerstreptococci per 100 ml

The Directive contains nomandatory standard forfaecal streptococci

The Directive contains nomandatory standard forfaecal streptococci


Appendix 4: Scottish marine environment data sources

The following is a list organisations, institutions,laboratories and companies that hold informationrelating to the Scottish marine environment.Scottish data have been extracted from IACMST(1995) and separated into categories dependenton whether all or part of the information held isbiological, biochemical/chemical or physical incontent.

Source IACMST. (1995). Directory of Marine Environmental

Datasets held by UK Laboratories. Vols 1 and 2:Academic Sector, Public Bodies, NERC-related

Laboratories, Private Companies. IACMSTInformation Document No. 4, Rickards, L. J.(ed.). British Oceanographic Data Centre onbehalf of the Inter-Agency Committee onMarine Science and Technology,.

Notea searchable database for all European data sets isnow available at:http://www.bodc.ac.uk/frames/index4.html?../services/edmed/index.html&2.


Organisation Geographicarea

Timeperiod

Data type Dataformat

Comments

BritishOceanographicData Centre(BODC)


Culterty FieldStation,University ofAberdeen

CunninghameDistrict Council

North-eastAtlantic andcontinentalshelf seasaround theBritish Isles

45° N to 65°N, 15° W to15° E

Ythan estuary,north-eastcoast ofScotland

AreasurroundingGreat andLittle CumbraeIslands, Firthof Clyde

1970onwards

Notspecified

Notspecified

Notspecified

Various parameters

UK Digital Marine Atlas(second edition): marinegeology andgeomorphology; marineand coastal parks,reserves and protectedareas; marine andcoastal conservation inGreat Britain; seabirds;sea mammals; marinebiology; currents, tidesand surges; winds,waves and weather;seawater temperature,salinity and nutrients;chemical distributions;exploitation of themarine environment;fishing areas and fishspawning areas; datacatalogues

Species (birds, fish,invertebrates),populations, nutrientconcentrations, algalabundance, coastalecology

Marine and intertidalecology (e.g. sites,habitats, species,communities,abundance, geology)

Electronicstorage

Electronicstorage

Hard copy

Paperreports

The UK ROSCOP (Report ofObservations/SamplesCollected by OceanographicProgrammes) data set comprisesover 4,000 forms completed bythe principal scientists ofresearch cruises undertakensince 1970. The forms arecompleted by scientists usingresearch vessels belonging tothe Natural EnvironmentResearch Council (NERC), theMinistry of Agriculture, Fisheriesand Food (MAFF), the ScottishOffice Agriculture and FisheriesDepartment (SOAFD) and thesmaller research vesselsbelonging to universitydepartments and marinebiological associations

The long-term data setsmaintained for the Ythan estuaryare considered to be veryvaluable for increasingunderstanding of eutrophicationprocesses

At Kames Bay, populations ofthe thin tellin, Angulus tenuis,have been monitored for over60 years, constituting one of thelongest series of observations onan intertidal species in the UK

Biological



Timeperiod


Comments

DunstaffnageMarineLaboratory(DML)/ScottishAssociation forMarine Science(SAMS)





Firth of Lorne,associatedsea lochs andadjacent seaareas

Firth of Lorne,associatedsea lochs andadjacent seaareas

RockallTrough,PorcupineSeabight

48–61° N;03–18° W,principallyRockallTrough, westof Ireland,includingsome samplesfromPorcupineSeabight

Tralee Bay,ArdmucknnishBay, nearOban, Argyll,Scotland

1970–1976

1969–1980

1975–1992

1973onwards

April1986 toDecember1989

Fish larvae in Scottishsea lochs. Marinebiology, fish, fisheriesstocks, fish larvae

Inshore fish in Scottishsea lochs. Marinebiology, fish, fisheriesstocks, fish larvae

Deep-sea fish from theRockall Trough andPorcupine Seabight

Deep-sea benthos of theRockall Trough area

Abundance and speciesdiversity of fish andcrustaceans on a Scottish(west coast) sandybeach: number ofindividuals per 100 m2,lengths and weights offish species, salinity,temperature, windvalues, number ofspecies at sample date,fish biomass per 100 m2

Paperrecords

Electronicstorage,paperreports

Electronicstorage

Electronicstorage, paperrecord,preservedspecimens


Seasonal sampling of fishlarvae; used extensively by SirFrederick Russell in his bookEggs and Larvae of BritishFishes. His originalidentifications are held atSAMS. Some use made ofmaterial in other publications

Catch data for trawls in the Firthof Lorne, Loch Linnhe, LochEtive, Loch Spelve, Loch Sunart,Sound of Mull and TireePassage

The project has primarily aimedto sample the macro- andmegabenthic community at twodeep-sea permanent stations ona seasonal and interannualbasis using epibenthic sled andAgassiz trawl respectively



Timeperiod


Comments






Loch Linnheand Loch Eil,west coast ofScotland

Central Firthof Clyde, westcoast ofScotland

Hunterstonpower stationandsurroundingareas (ClydeSea area)

Hunterstonpower stationandsurroundingareas (ClydeSea area)

North-eastAtlantic(Madeira–Faroes)

1963–1980

1979onwards

1960–1985

1960–1975(?)

1973–1983

West coast of ScotlandLoch Linnhe/Loch Eilbenthic ecology surveys:long-term changes in thebenthic ecology of LochLinnhe and Loch Eil;macrobenthicinvertebrateabundances, speciesnumbers and biomassquantified at c.10-weekintervals; sedimentarycarbon, nitrogen, redoxpotentials, acidity,temperatures, salinitiesand oxygen levels

Environmentalmonitoring survey ofGarroch Head sewagesludge disposal grounds

Hunterston powerstation, Clyde Sea area:sea biologicalpopulations time-series

Breeding behaviour ofAssellopsis intermedia inthe vicinity of Hunterstonpower station, ClydeSea area

Meiobenthos studies attwo sites west of Irelandand south-west PorcupineSeabight

Publishedmanuscripts/paperreports


Electronicstorage,biologicalsamples

PhD thesis,paper notes

PhD theses,biologicalsamples

The survey was initiated toassess the impact on thesedimentary ecology of the areaof the effluent from a pulp andpaper mill discharging into thenarrows between the two lochs.It was continued as a generalstudy of organic enrichment ofmarine sediments and of fjordicbenthic ecology

A monitoring survey to assessthe comparative condition of thesediments and fauna in the areaof the grounds where 1.5 ¥ 106wet tonnes of sewage sludge isdumped annually

Biological core samples weretaken to study densities ofvarious species in the areassurrounding Hunterston powerstation and Kames Bay, Millport

Fortnightly samples were takento study the breeding behaviourof the copepod Asellopsisintermedia



Timeperiod


Comments

Institute ofOceanographicSciences (IOS)DeaconLaboratory/James RennellCentre forOceanCirculation (JRC)



MAFFDirectorate ofFisheriesResearch,FisheriesLaboratory,Lowestoft



Eastern NorthAtlanticOcean. Workareas centredon EECstation48°50´ N,16°30´ W;31° N, 21oW; projectedsite at 20° N,30° W

Eastern NorthAtlanticOcean

North Atlantic(UK to CapeFarewell,Greenland)

Eastern IrishSea

North Sea

North Sea

1989onwards

1969onwards

1991onwards

1983–1988

1965–1990

1977–1991

DEEPSEAS, abyssalbenthic biology within theframework of IOSlaboratory researchproject 4 (LRP4): abyssalbiota, megafauna,macrofauna, meiofauna,foraminifera, bacteria,abundance, diversity,biomass, size spectra, lifehistory strategies

IOS Deacon Laboratorybiological database ofthe north-east Atlantic:macroplankton,micronekton

World Ocean CirculationExperiment (WOCE),CONVEX. temperature,salinity, transmittance,dissolved oxygen, nitrate,silicate, oxygen-16/oxygen-18 ratio,chlorofluoro-carbons,plankton, meteorologicalmeasurements, currentprofiles, bathymetry

Benthic survey: taxonomicdescription ofmacrobenthos, sediment

MAFF Directorate ofFisheries ResearchInternational Young FishSurve data set: lengthand quantitative estimateof catch; surface andbottom temperature andsalinity

North Sea GroundfishSurvey data set: lengthand total weight for allfinfish species, weightand numbers for benthicspecies; caesium-137sampling from seawaterand fish muscle tissue; adhoc biological sampling

Electronicstorage,biologicalsamples,photographicimages

Electronicstorage

Electronicstorage

Paper files,publishedliterature

Electronicstorage,paper files

Electronicstorage

The aim of DEEPSEAS is to studythe responses of deep-seabenthic and benthopelagiccommunities to perturbation

The IOS Deacon Laboratory hasbeen engaged in a series ofcomprehensive mid-watersampling programmes in theNorth Atlantic between theequator and 60° N and fromoffshore Europe and Africamainly to 33° W for many years

These data were collected toinvestigate the distribution ofwater masses and to derive fulldepth circulation

Spatial distribution of themacrobenthos in the muddysediments of the eastern IrishSea. Redistribution of sedimentbound artificial radionuclidesoriginating from the Sellafieldnuclear reprocessing plant

Initially designed to determinethe distribution and abundanceof adult and larval herring plusjuvenile gadoids and to monitorenvironmental parameters aspart of an ICES-coordinatedprogramme

Surveys were primarily designedto determine the distribution andabundance of demersal fishspecies and to monitorenvironmental parameters



Timeperiod


Comments







North Sea

NorthernNorth Sea

Mainlywestern IrishSea

Irish Sea,BristolChannel,westernEnglishChannel

Celtic Seaand EnglishChannel

Irish Sea

1992–1994(August toSeptembereach year);1991–1994(October toNovembereach year)

1978–1983

April toJune 1982and Aprilto June1985

Ongoing

1990–1991

1979–1992

Length and total weightfor all finfish species andthe total weight ofbenthic species andanthropogenic debris;age/maturity

Norway pout surveys inthe northern North Sea.Length and total weightfor cod, haddock,whiting, Norway pout,herring

Irish Sea Nephropslarvae survey: plankton,nutrients, temperature,salinity

Fish tagging data forcod, plaice, sole,spurdogs, rays,anglerfish

Gadoid survey: lengthand age/maturity; adhoc biological andphysical sampling

Irish Sea gadoid survey:length – all fish speciesand selected crustacea;maturity/age – cod,whiting, plaice and sole;ad hoc biological (e.g.weight, stomachcontents, benthos) andphysical (e.g. surfacetemperature and salinity)sampling

Electronicstorage

Electronicstorage,paperrecord

Paperrecord

Electronicstorage

Electronicstorage

Electronicstorage

ICES third- and fourth-quarterbottom trawl survey data sets

To determine the distribution andabundance of commercialgadoids in relation to thedistribution of Norway pout inorder to delimit an area wherea ban on industrial fishing couldbe imposed as a conservationmeasure

For estimation of the spawningstock biomass of the westernIrish Sea Nephrops

Surveys to determine thedistribution and abundance ofgroundfish, particularly cod

Main objective was to determinethe relative abundance of pre-recruit cod and whiting



Timeperiod


Comments








Celtic Sea,Irish Sea

WesternEuropeanShelf betweenShetland inthe north tothe southernpart of theBay of Biscayin the south

Various areasof the NorthSea

UK

North Seaand Irish Sea

UK; MainlyEnglishChannel,WesternApproaches,BristolChannel andNorth Sea

Irish Sea

1988onwards(Septembereach year,butincludingMarch from1993)

1982onwards

1962onwards

1970–1975;1979onwards

1982,1985 and1987

1981,1989 and1993

1983onwards

Near westerly groundfishsurveys: length, weight,age/maturity of fishspecies and selectedcrustacea

Western European shelfgroundfish survey: fishdistribution andabundance, size andage compositions, seasurface temperature,bottom temperature

Plankton, temperature,salinity

Inshore Waters DemersalYoung Fish Survey:abundance and lengthdistribution of smalldemersal fish, surfacewater salinity,temperature andsubstrate type

Abundance anddistribution of Nephropslarvae

Abundance anddistribution of ediblecrab larvae

Irish sea Nephropslength samples:carapace length ofmarket (landed) samples

Electronicstorage

Electronicstorage



Electronicstorage

Electronicstorage


Originally to investigate thedistribution and abundance ofjuvenile mackerel, but extendedto monitor the annual changesin distribution and abundance oflength and age of all finfishspecies caught

To provide abundance indices ofgroup 0 and group 1 sole andplaice



Timeperiod


Comments


MAFFDirectorate ofFisheriesResearch, FishDiseasesLaboratory,Weymouth

MarineBiologicalAssociation ofthe UK (MBA)

MarineBiologicalAssociation ofthe UK (MBA)

MarineConservationBranch of theJoint NatureConservationCommittee(JNCC)

Eastern IrishSea

Various areasof the NorthSea, SouthernBight, EnglishChannel, south-westernapproaches,Bristol Channel,Celtic Sea andIrish Sea

North-westScotland

Western Argyll(Mull of KintyretoArdnamurchanPoint), OuterHebrides, north-west Scotland(ArdnamurchanPoint to CapeWrath), MorayFirth(DuncansbyHead toPeterhead)

UK

1991onwards

1992onwards

1967onwards

1975–1980

1987onwards

Eastern Irish SeaNephrops discard data:numbers at size ofdiscarded andassociated landedNephrops by sex, andweights of samples

Marine fish diseasesurveys, includingmonitoring on dump sites

North-east England andnorth-west Scotlandrocky shores speciespopulation dynamic

Intertidal survey unitdatabase

MNCR database:conservation, marineconservation, marinesurvey, sites, habitats,species, communities,abundance,granulometry,physiography,references, bibliography,community classification,biotope classification,life forms, photographs,littoral, sublittoral,infralittoral, circalittoral,substratum, position, gridreference, county,region, salinity,exposure, geology,stratification, designation

Electronicstorage(spread-sheet), papercopy

Electronicstorage,paperrecord,histopatho-logicalsamples

Paperrecords


Electronicstorage

Monitoring trends for diseaseprevalences and investigationsinto the pathogenesis of newand emerging diseases

The data set comprises data onpopulation dynamics of ‘key’rocky shore species. There is anemphasis on recruitment

Currently holds data relating toaround 212 surveys carried outin Scotland, incorporating over6,400 survey stations. The datahave recently been transferredto an updated system calledMarine Recorder.



Timeperiod


Comments


Natural HistoryMuseum (NHM),London



North East RiverPurificationBoard (NERPB),now part of theScottishEnvironmentProtectionAgency (SEPA)

North East RiverPurificationBoard (NERPB)now part of theScottishEnvironmentProtectionAgency (SEPA)

Plymouth MarineLaboratory (PML)

Coastal areasof GreatBritain,includingNorthernIreland forestuaries

North-eastAtlantic

North-eastAtlantic

Oceans andseasadjoiningEurope

Grampian,east coast ofScotland


Irish Sea

1982onwards

August1989 toAugust1992

1973onwards

1850onwards

1987onwards

February1990 toFebruary1992

1987–1991

JNCC integrated coastaldatabase: vegetationcommunities, areas,human activities, siteprotection

North-east Atlanticabyssal polychaetes andnematodes: abundances,diversity, speciesrichness, equitability,trophic groups

North-east Atlantic deepdemersal fish data set:catch identified, countedand weighed at sea; sexand stomach contentswere noted

Foraminifera collection;plankton and benthos

Bathing waterbacteriological surveys:faecal coliforms per 100ml, total coliforms per100 ml, temperature,wind speed anddirection, presence of oils

TBT imposex data

PML Irish Sea Projectdata set. Phytoplankton,zooplankton, fish larvae,fish eggs, primaryproduction, particlecharacterisation, salinity,temperature, chlorophyll

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage,paperrecord,preservedspecimens


Paperreports

Electronicstorage

A range of data sets arecombined into a single module,including national inventories ofsand dunes, saltmarshes,estuaries, cliffs, shingle sites;also a map-derived data set ofthe areas and lengths of ‘coastalresources’ by 10 km

Multiple oceanic sites in theeastern North Atlantic

The aim was to study theproductivity of bothphytoplankton and zooplankton,in relation to the survival of fishlarvae, and to investigate howdifferences in ecosystemstructure might influence theavailability of food andsuccessful recruitment of fish



Timeperiod


Comments

Plymouth MarineLaboratory(PML)


Scottish OfficeAgriculture andFisheriesDepartment(SOAFD),MarineLaboratory,Aberdeen

SOAFD, MarineLaboratory,Aberdeen


Sea MammalResearch Unit(SMRU)

Sea MammalResearch Unit(SMRU)

Celtic Sea

River Edenestuary, Fife

North Sea

Scottishcoastal waters

Scottishcoastalwaters,central andnorthernNorth Sea,Rockall, north-east Atlantic

UK coastespeciallyScotland

InnerHebrides,OuterHebrides,Orkney, Isleof May, LochEriboll (i.e. allthe main greyseal breedingsites in theUK)

1982–1986

1976–1979

1980–1986

1989onwards

1986onwards

1988onwards

1960onwards

PML Celtic Sea Projectdata set: phytoplankton,zooplankton, fish larvae,fish eggs, primaryproduction, particlecharacterisation, salinity,temperature, chlorophyll

Nitrogen cyclingparameters, bacterialnumbers

ICES Benthos WorkingGroup North SeaSurvey: benthic fauna,carbon, chlorophyll,heavy metals, proteins

Metals in organisms,seawater, sediments andrainwater; trace metals,mercury

Zooplankton data:species composition,biomass concentration,dry weight, feeding andgrowth rates,length/weight data andother derived parameters

Common sealdistribution and numbersin August

Grey seals: pupproduction andpopulation size

Electronicstorage,paperrecord,publishedreports

PhD thesis,publishedreports

Electronicstorage

Electronicstorage

Electronicstorage,manuscript


Photographs

The project was an investigationof the role of picoplankton inpelagic productivity of a shelfsea

Nitrogen cycling parametersand bacterial numbers werecollected to study the rates ofsediment nitrification anddenitrification in nutrient lensesin the sediments

From various internal projects,national and internationalprogrammes

Seal population data arecollected in late July and earlyAugust during the common sealannual moult

Annual grey seal surveys areconducted during the breedingseason, from late Septemberthrough late November



Timeperiod


Comments

Sir Alister HardyFoundation forOcean Science(SAHFOS)

Solway RiverPurificationBoard (SRPB)

Solway RiverPurificationBoard (SRPB),now part of theScottishEnvironmentProtectionAgency (SEPA)

Tay RiverPurificationBoard (TRPB),now part of theScottishEnvironmentProtectionAgency (SEPA)



North Atlantic(35° N to 60°N, 71° W to11° E)

Inner SolwayFirth beaches

Beach andseabedaround theGallowayCreameroutfall, LochRyan, south-west Scotland

East coast ofScotland

East coast ofScotland

Tay estuary

1931onwards

1987onwards

1987onwards

1988 to1992(summerperiods)

1988 to1992

1989–1992

North Atlanticcontinuous planktonrecorder survey data set:phytoplankton,zooplankton

Intertidal invertebratecommunities, particlesize analysis (PSA), tracemetals in sediments

Invertebratecommunities, particlesize analysis (PSA)

Bathing water survey:total coliforms andfaecal coliforms per 100 ml seawater

Shellfish contaminationsurveys: faecal coliformsper 100 g tissue andfluid

Faecal coliforms per 100ml water

Electronicstorage

Paperreports

Paperreports

Paperreports

Paperreports

Paperreports

The continuous planktonrecorder is a piece of apparatustowed by vessels for samplingplankton near the sea surface.Continuous plankton recordersare towed by ships ofopportunity at a depth of 10 mand are deployed, as far aspossible, at monthly intervalsover a standard set of routes

Twenty-four sampling stations onthe intertidal zone of the InnerSolway Firth, betweenDorknockbrow and Arbigland(54°53´ N, 03°11´ W to54°54´ N, 03°34´ W)

Annual survey of 24 samplingpoints (16 subtidal, eightintertidal) at the head end ofLoch Ryan.

Samples taken four times peryear at EC-designated sitesusing caged or native musselsfrom the intertidal region

Offshore samples of surfacewater taken four times per year



Timeperiod


Comments





University ofWales, Bangor,School ofOcean Sciences


Barnhillsewageoutfall, Tayestuary

Tay estuary

Inner Edenestuary, eastcoast ofScotland

Dundeeforeshorebetween roadbridge andBroughtyCastle

Loch Creran,Argyll

Loch Striven,Argyll

1992

1991–1992

1989 and1992

1989 and1991

1971–1982

1980–1994

Fauna

Fauna and sedimentchemistry

Fauna and sedimentorganic content

Fauna, loss-on-ignitionand particle sizeanalysis

Phytoplankton study:temperature, salinity,chlorophyll, nutrients,phytoplankton speciescomposition

Temperature, salinity,currents, opticalmeasurements, nutrients,chlorophyll, zooplanktonbiomass, phytoplanktonspecies composition

Paperreports

Paper report

Paperreports

Paperreports

Paperrecords,reports,theses anddigital tapes

Paperrecords,reports,theses anddigital data

A study of the relationshipbetween phytoplanktoncommunity composition andhydrography



Timeperiod


Comments

BritishGeologicalSurvey (BGS)




UKcontinentalshelf andadjacentslopes

UKcontinentalshelf andadjacentslopes –except theIrish Sea,Celtic Seaand EnglishChannel


Shelf seasaround theUK, easternNorth Atlantic

1966onwards

1975–1990

1970onwards

1893onwards

Grain size, weights ofgravel, sand and mudfractions, and carbonatecontent of the fractions;whole and half phianalysis of the sandfraction

Marine geochemicaldata. Trace elementgeochemicalconcentrations of sea-bed samples.

Various parameters

Temperature, salinity,nutrients, oxygen, pH,alkalinity, chlorophyll a

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Concentrations of up to 30 traceelements in approximately11,000 seabed samples

The UK ROSCOP data setcomprises over 4,000 formscompleted by the principalscientists of research cruisesundertaken since 1970. Theforms are completed byscientists using research vesselsbelonging to the NaturalEnvironment Research Council(NERC), the Ministry ofAgriculture, Fisheries and Food(MAFF), the Scottish OfficeAgriculture and FisheriesDepartment (SOAFD) and thesmaller research vesselsbelonging to universitydepartments and marinebiological associations

Data routinely collected by UKresearch and naval vessels sincethe beginning of the twentiethcentury. Compiled by the ICESOceanographic Data Centre

Biological and chemical



Timeperiod


Comments





45–65° N,15° W to 15°E

Scottishcontinentalshelf, NorthChannel, Seaof theHebrides,Minches


Central Firthof Clyde, westcoast ofScotland

Notspecified

1976–1988

1963–1980

1979onwards


Radiocaesium (caesium-134 and caesium-137)surveys upon thecontinental shelf west ofScotland


Environmentalmonitoring survey ofGarroch Head sewagesludge disposal grounds

Electronicstorage

Manuscript



Water samples for radiocaesiumanalysis were collected inassociation with conductivity,temperature and depth (CTD)sections upon the westernScottish shelf. The data havebeen used to obtain travel timeswithin the coastal current systemand budgets of ocean/shelfexchange


A monitoring survey to assessthe comparative condition of thesediments and fauna in the areaof the grounds where 1.5 x106

wet tonnes of sewage sludgeare dumped annually



Timeperiod


Comments







Loch Eil andcontrol stationby GreagIsland, west ofDunstaffnage

Cat Firth,Garth’s Voe,Gluss Vos andSullom Voe,around theShetlandIslands, northof Scotland

Upper andmiddle basinsof Loch Etive,Argyll

West coast ofScotland, Firthof Lorn, fromthe head ofLoch Eil toColonsay

Floodedquarry onEasdaleIsland, offSeil, Argyll,west coast ofScotland

West coast ofScotland LochEtive, LochGoil, LochFyne

November1975 toMarch1977

June 1977toSeptember1978

June 1980toNovember1982


March toNovember1984

1989

West coast of ScotlandLoch Eil nutrient data.Temperature, salinity,phosphate, nitrate,nitrite, ammonium,dissolved organicphosphorus, dissolvedorganic nitrogen,chlorophyll,phaeopigment, acidratio.

Nutrient data set fromaround the ShetlandIslands: temperature,salinity, phosphate,nitrate, nitrite,ammonium, dissolvedorganic phosphorus,dissolved organicnitrogen, chlorophyll,phaeopigment, acidratio

Loch Etive nutrient data:temperature, salinity,dissolved oxygen,phosphate, nitrate andnitrite, silicate, dissolvedorganic phosphorus,chlorophyll,phaeopigment, acidratio

West coast of Scotland,Firth of Lorn nutrientdata: temperature,salinity, nitrate andnitrite, silicate,chlorophyll,phaeopigment, acidratio

Easdale quarry, EasdaleIsland, Firth of Lorn, westcoast of Scotland,nutrient data: nitrite,nitrate and nitrite,dissolved silicon

West coast of ScotlandLoch Etive, Loch Goiland Loch Fyne nutrientdata: nitrate and nitrite,phosphate, silicate,ammonium



Electronicstorage, PhDthesis

Paperrecord

Paperrecord,paperreports

Electronicstorage



Timeperiod


Comments





Kyle andCarrick DistrictCouncil


West coast ofScotland LochLinnhe, Argyll


North-eastAtlantic(Iceland–Scotland–Faroesregion)

Eastern NorthAtlantic

Barassie Shorein the north ofKyle andCarrick districtto Finnarts Bayin the extremesouth of Kyleand Carrickdistrict

UK

February toJune 1990

1991onwards

1986onwards

1975onwards

1985onwards

1959onwards

West coast of ScotlandLoch Linnhe nutrientdata: nitrate and nitrite,phosphate, silicate,ammonium

World OceanCirculation Experiment(WOCE), CONVEX:temperature, salinity,transmittance, dissolvedoxygen, nitrate, silicate,oxygen-16/oxygen-18ratio,chlorofluorocarbons,plankton, meteorologicalmeasurements, currentprofiles, bathymetry

NANSEN (NorthAtlantic Norwegian SeaExchange); WorldOcean CirculationExperiment (WOCE):temperature, salinity,transmittance, dissolvedoxygen, current speedand direction, silicate,surface meteorology,wave parameters,fluorescence

IOS Deacon Laboratorymarine chemistry data:nutrients, chemicalanalysis of sediments,solid-phasegeochemistry, porewater chemistry

Common radioactivepollutants

Radionuclidemeasurements(Radbase):concentrations ofradionuclides and beta-and gamma-ray doserates

Electronicstorage

Electronicstorage

Electronicstorage


Electronicstorage

Paperrecords andelectronicformat


All radiation data are compiledon a calendar year basis andinformation is available to thepresent date

Mostly shelf waters around theUK, but also some oceanic datafor the north-east Atlantic andsome UK surface water data



Timeperiod


Comments








North Sea,EnglishChannel andIrish Sea

Eastern IrishSea

Irish Sea,includingSolway Firth,Esk andRibbleestuaries

Irish Sea,EnglishChannel,Malin Shelf,North Sea,NorwegianSea, BarentsSea

Irish Sea,southernNorth Sea



1960onwards

1983–1988

1968onwards

1972onwards

1983onwards


1987onwards

Nutrients: total oxidisednitrogen, nitrite, silicate,phosphate, ammonia;temperature and salinity

Benthic survey:taxonomic description ofmacrobenthos, sediment

Artificial radionuclides(plutonium, americium,curium, caesium andother neutron activationand fission products);sediment type

Artificial radionuclides(caesium, plutonium,americium, technetium,antimony), Kd values,suspended load, salinity

Naturally occurringradionuclides (uranium,thorium, polonium, leas,radium), Kd values,suspended load, salinity


Bathing waterbacteriological surveys.Faecal coliforms per 100ml, total coliforms per100 ml, temperature,wind speed anddirection, presence ofoils

Electronicstorage


Electronicstorage,paper files,publishedliterature

Electronicstorage,paper files,publishedreports


Paperrecord


Samples collected from 156MAFF cruises, andmeasurements for 11,000samples

Spatial distribution of themacrobenthos in the muddysediments of the eastern IrishSea. Redistribution of sediment-bound artificial radionuclidesoriginating from the Sellafieldnuclear reprocessing plant

Distribution and behaviour ofsediment-bound artificialradionuclides released from thenuclear reprocessing plant atSellafield

As part of a collaborative ECMAST project. The distributionof artificial radionuclidesreleased into the marineenvironment as a result of fuelreprocessing (Sellafield, LaHague, Dounreay)




Timeperiod


Comments

North East RiverPurificationBoard (NERPB)now part of theScottishEnvironmentProtectionAgency (SEPA)






ProudmanOceanographicLaboratory(POL)


Irish Sea

North Sea

River Edenestuary, Fife

North Sea(Dover Straitsto Shetland)

NE Atlantic

Continentalshelf andslope areasaround theBritish Isles(e.g. NorthSea, IrishSea, CelticSea)


1987–1991

May 1986to February1992

1976–1979

1986–1991

1987–1991

1974onwards

TBT imposex data

PML Irish Sea Projectdata set: phytoplankton,zooplankton, fish larvae,fish eggs, primaryproduction, particlecharacterisation, salinity,temperature, chlorophyll

North Sea nutrients:nutrients, primaryproductivity, nitrogenassimilation

Nitrogen cyclingparameters, bacterialnumbers

Undulatingoceanographic recorder(UOR) data: CTD,chlorophyll,photosynthetically activeradiation (PAR)

Undulatingoceanographic recorder(UOR) data: CTD,chlorophyll,transmittance

POL databank ofCTD/STD profiles:conductivity/salinity,temperature,depth/pressure,occasionally oxygen,transmittance

Paperreports

Electronicstorage


PhD thesis,publishedreports

Electronicstorage

Electronicstorage

Electronicstorage


Nine cruises following a trackcovering the whole of the NorthSea

Nitrogen cycling parametersand bacterial numbers werecollected to study the rates ofsediment nitrification anddenitrification in nutrient lensesin the sediments



Timeperiod


Comments



SOAFD, MarineLaboratory,Aberd



Tay EstuaryResearch Centre(TERC),Universities ofDundee and StAndrews



North Sea



Scottishcoastalwaters,central andnorthernNorth Sea,Rockall, northeast Atlantic


Tay estuary,east coast ofScotland

Tay estuary

Inner Edenestuary, eastcoast ofScotland

1980–1986

1989onwards

1989onwards

1893onwards

1987onwards

June 1972(neap andspringtides)

1991–1992

1989 and1992

ICES Benthos WorkingGroup North SeaSurvey: benthic fauna,carbon, chlorophyll,heavy metals, proteins


Organochlorines

Hydrographic data:pressure (depth),temperature, salinity,(sigma-t), oxygen,phosphate, nitrate,silicate, ammonia,chlorophyll a,phaeopigments,particulate organiccarbon and particulateorganic nitrogen


Data from physical andchemical measurements:tide height, currentspeed and direction,water temperature andsalinity, suspendedsediment concentration

Fauna and sedimentchemistry

Fauna and sedimentorganic content

Electronicstorage

Electronicstorage

Electronicstorage


Paperreports

Hard copy

Paper report

Paperreports


Twenty-four sampling stations onthe intertidal zone of the InnerSolway Firth, betweenDorknockbrow and Arbigland(54°53´ N, 03°11´ W to54°54´ N, 03°34´ W)

A major programme designedso that simultaneous changes invarious physical and chemicalparameters could be measuredthroughout the entire length ofthe Tay estuary



Timeperiod


Comments




Estuaries ofthe riversSouth Esk, Tayand Eden andsome coastalwaters

Loch Creran,Argyll

Loch Striven,Argyll

1980–1992

1971–1982

1980–1994

Standard pollutionparameters, metals


Temperature, salinity,currents, opticalmeasurements, nutrients,chlorophyll, zooplanktonbiomass, phytoplanktonspecies composition

Paperreports


Paperrecords,reports,theses anddigital data




Timeperiod


Comments

Amoco (UK)Exploration

BP ExplorationOperatingCompany Ltd

British Gas plc







North Sea

North Sea

NorthChannel, IrishSea, NorthSea, west ofShetland




UK and north-westEuropeancontinentalshelf



1972onwards

1971–1992

July 1980toDecember1984

1966onwards

1975onwards

1966onwards

1981–1992

1966–1991

1969onwards

Wind, wave and waterlevel data from Leman,Indefatigable, Lomondand North Everestplatforms

BP current meter datafrom the North Sea andEnglish Channel: currentspeed and direction

Current speed anddirection, water levels

UK Offshore RegionalMapping Programme:index data, geologicaldescriptions, samples,results of analyses (non-digital)

Marine geotechnicaldata: shear andcompressive strengths

Grain size, weights ofgravel, sand and mudfractions and carbonatecontent of the fractions;whole and half phianalysis of the sandfraction

BIRPS (British InstitutionsReflection ProfilingSyndicate) deep seismicdata

Marine geophysical andseismic records: indexdata, analogue ship-borne gravity andmagnetic records,seismic records, side-scan records, echo-sounder records

Composite boreholelogs, results of analyses,interpretations, reportsand core material.


Electronicstorage

Electronicstorage

Electronicstorage,paperrecords

Electronicstorage

Electronicstorage

Electronicstorage,paperrecords

Paperrecords,samples

Electronicstorage

Collection of approximately35,000 offshore samples, usinggrab samplers and shallowcoring devices (to a maximumdepth of 6 m below the seabed)

UK Offshore Regional MappingProgramme and consortium-funded projects; NERC LandOcean Interaction Study (LOIS)

Physical



Timeperiod


Comments







UK land andcontinentalshelf, andadjacentmarine areas


Continentalshelf areasaround theBritish Isles

North AtlanticOcean

North-eastAtlantic andcontinentalshelf areasaround theBritish Isles

North-westEuropeanShelf (NorthSea, IrishSea, EnglishChannel)

c. 1950onwards

1970onwards

1970–1983

1970–1983

1967onwards

1970–1988

Digital marine linegravity (unadjusted andadjusted), digitalland/seabed pointgravity, gridded gravity,digital aeromagnetics,digital ship magnetics,digital water depths

Various parameters

Total pressure (seawaterplus atmospheric),relative pressure

Total pressure (seawaterplus atmospheric),relative pressure

UK national databank ofmoored current meterdata: current speed,current direction; alsotemperature, pressureand conductivity

Moored current meterdata: tidal constituents

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

From UK Offshore RegionalMapping Programme, UKOnshore Gravity andAeromagnetics MappingProgrammes, Marine GravityCompilations and Adjustments

The UK ROSCOP data setcomprises over 4,000 formscompleted by the principalscientists of research cruisesundertaken since 1970. Theforms are completed byscientists using research vesselsbelonging to the NaturalEnvironment Research Council(NERC), the Ministry ofAgriculture, Fisheries and Food(MAFF), the Scottish OfficeAgriculture and FisheriesDepartment (SOAFD) and thesmaller research vesselsbelonging to universitydepartments and marinebiological associations

Time-series measurements fromoffshore pressure gaugesmounted on the sea floorTime-series measurements fromoffshore pressure gaugesmounted on the sea floor



Timeperiod


Comments









North Atlanticand UKcontinentalshelf

Shelf seasaround theUK, easternNorth Atlantic

North Sea

Scottishcontinentalslope (51–63°N, 0–15° W)



Offshore siteson the UKcontinentalshelf

North-eastAtlantic(47–64° N,40° W to 6°E)

1975onwards

1893onwards

March toJune 1976

August1982 toMarch1983

1955onwards

1976onwards

1973–1988

Notspecified

UK National Databankof CTD/salinity,temperature, depth (STD)profiles:conductivity/salinity,temperature,depth/pressure,occasionally oxygen,transmittance

Temperature, salinity,nutrients, oxygen, pH,alkalinity, chlorophyll a

Joint North Sea DataAcquisition Project(JONSDAP) data: currentspeed and direction,temperature

Continental SlopeExperiment (CONSLEX)data set: current speed,current direction,temperature, pressure

UK National Databankof wave data: ship-bornewave recorders, mooredwaverider buoys,pressure recorders

One-dimensional wavespectra collected by UKlaboratories: waveenergy spectra computedfrom sea surfacedisplacement/heave

UK Offshore OperatorsAssociation (UKOOA)meteorological/oceandata set: wind, wave,current and surfacemeteorologicalparameters

Digital version of IOSbathymetric chart of thenorth-east Atlantic (1:2.4million): bathymetricdepth contours

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Data routinely collected by UKresearch and naval vessels sincethe beginning of the twentiethcentury. Compiled by the ICESOceanographic Data Centre

Collaborative exercise betweenthe Institute of OceanographicSciences Deacon Laboratory,Proudman OceanographicLaboratory, DunstaffnageMarine Laboratory, ScottishOffice Agriculture and FisheriesDepartment and the Ministry forAgriculture, Fisheries and Fooddesigned to study watermovements across the Scottishcontinental slope



Timeperiod


Comments






45–65° N,15° W to 15° E

North Sea

North Sea,Irish Sea,EnglishChannel,north-eastAtlantic to15° W

Betweenapproximately60° N and60° S

North Atlantic

Notspecified

1966–1976

1963–1990

April 1975toNovember1978

1945–1983


North Sea wave model(NORSWAM) input dataset: wind andatmospheric pressure

MAFF sea surfacetemperature and salinitydata set (ship routes toand from the UK). seasurface temperature,surface salinity

GEOS-3 satellite waveheight and wind speeddata

North Atlantic oceanweather ship (OWS)surface meteorologicaldata: wind direction,wind speed, airtemperature, wetbulb/dew pointtemperature, airpressure, cloud type,height and coverage,visibility, sea surfacetemperature, waveheight, period anddirection

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

Undertaken in order tosupplement the limited numberof measured wave data thatwere available in the northernNorth Sea on which to basedesign and certification criteriafor offshore structures



Timeperiod


Comments



BT (Marine) Ltd

ChevronPetroleum UKLtd

Cromarty FirthPort Authority(CFPA)

DefenceResearchAgency (DRA)




North Atlantic

North Sea

Girvan,Scotland, toLarne, NorthernIreland; Irish Sea

West ofShetlands

Invergordon,Cromarty Firth(east coast ofScotland) tidalrecords

Rockall Trough,eastern NorthAtlantic

Rockall Trough,Jan Mayan front,marginal icezone, easternNorth Atlantic,Greenland Sea,Norwegian Sea

Iceland–Faeroesfrontal zone, Denmark StraitandFaeroe–Shetlandgap, NorthAtlantic

North-eastAtlantic

1910–1990

1968–1985

1992

April toSeptember1985

1981onwards

From 28May to 9June 1983

2 May to 6June 1988

9 July to17 August1987 andfrom 15April to 24May 1988

1986–1989

North Atlantic oceanweather ship (OWS)temperature and salinityhydrocast data

Climatological atlas ofsalinity and temperaturefor the North Sea

Burial assessment survey,Scotland to NorthernIreland no. 2 cableroute: bathymetry,seabed sediments,tension and penetrationof burial assessment tool,pitch, roll and ship’sspeed

Current meter data to thewest of Shetlands

Tide gauge measurementof sea level

Internal wave climate(temperature) fromthermistor chainmeasurements

Temperature,conductivity, surfacemeteorology, surfaceparameters

Acoustic data for NATOMilitary Oceanography(MILOC) Group

Satellite-tracked droguedrifts over Faeroe Bankand the Faeroe–Icelandridge

Electronicstorage

Electronicstorage

Paper charts

Electronicstorage

Papergraphs(weeklyrecords)

Electronicstorage

Electronicstorage

Electronicstorage

Electronicstorage

The data set was compiled bythe Institut fuer Meereskunde,Hamburg, Germany

The data have been screenedfor format and data errors andcorrected to produce a ‘clean’data set

All data have been screened forformat and data errors andcorrected to produce a ‘clean’data set

All data have been screened forformat and data errors andcorrected to produce a ‘clean’data set



Timeperiod


Comments





DunstaffnageMarineLaboratory(DML)/ScottishAssociation forMarine Science



North-eastAtlantic,northernRockallChannel,Faeroe Bank

Scottishcontinentalshelf, NorthChannel, Seaof theHebrides,Minches

Scottishcontinentalshelf, NorthChannel, Seaof theHebrides,Minches, Outer Firth ofClyde

North-eastAtlantic,RockallChannel,57–58° N

North-eastAtlantic,RockallChannel,56–58° N

Loch Etive:55°30´ N,5o10´ W

Scottish westcoast

September1987 toOctober1988

1976–1988

1975onwards

1975onwards

1948onwards

1970–1973

To 1986

Norwegian Sea deep-water overflow acrossthe Wyville–Thomsonridge: current speed anddirection, CTD profiles

Radiocaesium (caesium-134 and caesium-137)surveys upon thecontinental shelf west ofScotland

CTD sections upon thecontinental shelf west ofScotland: water columntemperature and salinity

Rockall channel CTDsection time series: watercolumn temperature andsalinity

Rockall Channel surfacetemperature and salinitytime-series

West of Scotland LochEtive CTD data:temperature and salinity

Catalogue of Scottishsea lochs: bathymetryand hypsography.

Electronicstorage

Manuscript

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Manuscript

Printedtables

Electronicstorage,paper report

Water samples for radiocaesiumanalysis were collected inassociation with CTD sectionsupon the western Scottish shelf.The data have been used toobtain travel times within thecoastal current system andbudgets of ocean/shelfexchange

Loch Etive is a Scottish fjord.Fifteen CTD stations in LochEtive were surveyed every twoweeks in 1970 to 1973. Theaim of the experiment was todescribe the aperiodic changesin the water masses of the lochresulting from fluctuatingfreshwater flows into the fjordsystem



Timeperiod


Comments







Loch Linnhe:55 o50´ N,5o15´ W

Sleat Sound:57o08´ N5o45´ W

Tralee Bay,ArdmucknnishBay, nearOban, Argyll,Scotland


UK shelf seasincluding sealochs andRockallChannel

Hunterstonpower stationandsurroundingareas (ClydeSea Area)

1990–1992

1990–1992

April 1986toDecember1989

1963–1980

1975onwards

1960–1985

West of Scotland LochLinnhe CTD data:temperature and salinity

West of Scotland Soundof Sleat CTD data:temperature and salinity

Abundance and speciesdiversity of fish andcrustaceans on a Scottish(west coast) sandybeach: number ofindividuals per 100 m2,lengths and weights offish species, salinity,temperature, windvalues, number ofspecies at sample date,fish biomass per 100 m2


Current meter datacollected mainly in UKshelf seas: current speedand direction and(usually) temperature

Hunterston powerstation, Clyde Sea areasea temperature time-series

Electronicstorage

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Electronicstorage


The aim of the experiment wasto describe the aperiodicchanges in the water masses ofthe loch resulting fromfluctuating freshwater flows intothe fjord system

The aim of the experiment wasto describe the aperiodicchanges in the water masses ofthe sound


Temperature data logged to beused in conjunction withbiological samples taken tomonitor effects of warm watereffluent from the nuclear powerstation at Hunterston



Timeperiod


Comments







NortheastAtlantic

Loch Eil andcontrol stationby GreagIsland, west ofDunstaffnage

Upper andmiddle basinsof Loch Etive,Argyll

West coast ofScotland, Firthof Lorn, fromthe head ofLoch Eil toColonsay


Eastern NorthAtlantic

May 1983to February1985

November1975 toMarch1977

June 1980toNovember1982


1991onwards

1967–1990onwards

DML north-east Atlanticdrifters: drift velocities,sea surface temperature

West coast of ScotlandLoch Eil nutrient data:temperature, salinity,phosphate, nitrate,nitrite, ammonium,dissolved organicphosphorus, dissolvedorganic nitrogen,chlorophyll,phaeopigment, acidratio

Loch Etive nutrient data:temperature, salinity,dissolved oxygen,phosphate, nitrate andnitrite, silicate, dissolvedorganic phosphorus,chlorophyll,phaeopigment, acidratio

West coast of Scotland,Firth of Lorn nutrientdata: temperature,salinity, nitrate andnitrite, silicate,chlorophyll,phaeopigment, acidratio

World OceanCirculation Experiment(WOCE), CONVEX:temperature, salinity,transmittance, dissolvedoxygen, nitrate, silicate,oxygen-16/oxygen-18ratio, chlorofluoro-carbons, plankton,meteorologicalmeasurements, currentprofiles, bathymetry

CTD, SEASOAR andcurrent meter data fromthe eastern NorthAtlantic Ocean:temperature, salinity,dissolved oxygen,transmittance,fluorescence, currentspeed and direction

Electronicstorage


Electronicstorage, PhDthesis

Paperrecord

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Moored current meter data havebeen collected since 1967,mainly in the eastern NorthAtlantic, concentrating on theareas to the north and west ofScotland, the west of Irelandand the Madeira abyssal plain,often in water depths of over4,000 m



Timeperiod


Comments







North-eastAtlantic(Iceland–Scotland–Faroesregion)

North-eastAtlantic,North Sea,Irish Sea,EnglishChannel,DenmarkStrait andsouth-westIndian Ocean

PrimarilyNorth Seaand Irish Sea,some NorthAtlantic

North Sea,Irish Sea,EnglishChannel

North Sea,EnglishChannel andIrish Sea

Eastern IrishSea

1986onwards

1968onwards

1980onwards

1930–1960

1960onwards

1983–1988

NANSEN (NorthAtlantic Norwegian SeaExchange); WorldOcean CirculationExperiment (WOCE):temperature, salinity,transmittance, dissolvedoxygen, current speedand direction, silicate,surface meteorology,wave parameters,fluorescence

Current meter data set:current speed, currentdirection, alsotemperature, pressureand conductivity

Temperature, salinity

Temperature and salinity:water bottle data set

Nutrients: total oxidisednitrogen, nitrite, silicate,phosphate, ammonia;temperature and salinity

Benthic survey:taxonomic description ofmacrobenthos, sediment

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Data holdings areapproximately 1,400 dataseries. Data records containcurrent speed and direction. Inaddition, temperature is oftenmeasured and pressure andconductivity are occasionallymeasured.

CTD dataset collected on severalcruises each year

Collected mainly in the Northand Irish Seas. Includes almost7,000 stations

Samples collected from 156MAFF cruises, andmeasurements for 11,000samples

Spatial distribution of themacrobenthos in the muddysediments of the eastern IrishSea. Redistribution of sediment-bound artificial radionuclidesoriginating from the Sellafieldnuclear reprocessing plant



Timeperiod


Comments


MAFF Directorate ofFisheriesResearch,FisheriesLaboratory,Lowestoft






Irish Sea,includingSolway Firth,Esk andRibbleestuaries

Irish Sea,EnglishChannel,Malin Shelf,North Sea,NorwegianSea, BarentsSea

Irish Sea,southernNorth Sea

North Sea

North Sea


Celtic Seaand EnglishChannel

1968onwards

1972onwards

1983onwards

1965–1990

1977–1991


1990–1991

Artificial radionuclides(plutonium, americium,curium, caesium andother neutron activationand fission products);sediment type

Artificial radionuclides(caesium, plutonium,americium, technetium,antimony), Kd values,suspended load, salinity

Naturally occurringradionuclides (uranium,thorium, polonium, leas,radium), Kd values,suspended load, salinity

MAFF DFR InternationalYoung Fish Survey (IYFS)data set: length andquantitative estimate ofcatch; surface andbottom temperature andsalinity

North Sea GroundfishSurvey (NSGFS) dataset: length and totalweight for all finfishspecies, weight andnumbers for benthicspecies; caesium-137sampling from seawaterand fish muscle tissue;ad hoc biologicalsampling


Gadoid survey: lengthand age/maturity; adhoc biological andphysical sampling.

Electronicstorage,paper files,publishedliterature



Electronicstorage,paper files

Electronicstorage

Paperrecord

Electronicstorage

Distribution and behaviour ofsediment-bound artificialradionuclides released from thenuclear reprocessing plant atSellafield

As part of a collaborative ECMAST project. The distributionof artificial radionuclidesreleased into the marineenvironment as a result of fuelreprocessing (Sellafield, LaHague, Dounreay)

Initially designed to determinethe distribution and abundanceof adult and larval herring plusjuvenile gadoids and to monitorenvironmental parameters aspart of an ICES-coordinatedprogramme

Surveys were primarily designedto determine the distribution andabundance of demersal fishspecies and to monitorenvironmental parameters


Surveys to determine thedistribution and abundance ofgroundfish, particularly cod



Timeperiod


Comments





Marine AdvisoryService(CommercialServices),MeteorologicalOffice

Irish Sea

WesternEuropeanShelf betweenShetland inthe north tothe southernpart of theBay of Biscayin the south

Various areasof the NorthSea

UK

Various fixedpoints on theNorth Atlanticand NorthSea

1979–1992

1982onwards

1962onwards

1970–1975;1979onwards

1945onwards

Irish Sea gadoid survey:length -–all fish speciesand selected crustacea;maturity/age - cod,whiting, plaice and sole;ad hoc biological (e.g.weight, stomachcontents, benthos) andphysical (e.g. surfacetemperature and salinity)sampling

Western European shelfgroundfish survey: fishdistribution andabundance, size andage compositions, seasurface temperature,bottom temperature

Plankton, temperature,salinity

Inshore waters demersalyoung fish survey:abundance and lengthdistribution of smalldemersal fish, surfacewater salinity,temperature andsubstrate type

Climatological MarineData Bank: wind speed,wind direction, waveheight, wave period,wave direction, airtemperature, sea surfacetemperature, visibility,sea level atmosphericpressure, cloud

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Main objective was to determinethe relative abundance of pre-recruit cod and whiting

Originally to investigate thedistribution and abundance ofjuvenile mackerel, but extendedto monitor the annual changesin distribution and abundance oflength and age of all finfishspecies caught

To provide abundance indices ofgroup 0 and group 1 sole andplaice

Meteorological observationsmade at fixed points (e.g. lightvessels, ocean weather ships,offshore platforms)



Timeperiod


Comments







UK

Coastal areasof GreatBritain,includingNorthernIreland forestuaries

Irish Sea

Bay of Biscayand CelticSea

North Sea(Dover Straitsto Shetland)

North-eastAtlantic

1987onwards

1982onwards

1987–1991

1980onwards

1986–1991

1987–1991

MNCR Database:conservation, marineconservation, marinesurvey, sites, habitats,species, communities,abundance,granulometry,physiography,references, bibliography,community classification,biotope classification,life forms, photographs,littoral, sublittoral,infralittoral, circalittoral,substratum, position, gridreference, county,region, salinity,exposure, geology,stratification, designation

JNCC Integrated CoastalDatabase: vegetationcommunities, areas,human activities, siteprotection

PML Irish Sea Projectdata set: phytoplankton,zooplankton, fish larvae,fish eggs, primaryproduction, particlecharacterisation, salinity,temperature, chlorophyll

Physical oceanography –slope currents andsurface transport.temperature, salinity,currents

Undulatingoceanographic recorder(UOR) data: CTD,chlorophyll,photosynthetically activeradiation (PAR)

Undulatingoceanographic recorder(UOR) data: CTD,chlorophyll,transmittance

Electronicstorage

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Currently around 450 surveys,1,900 sites and 20,000habitats

A range of data sets arecombined into a single module,including national inventories ofsand dunes, saltmarshes,estuaries, cliffs, shingle sites;also a map-derived data set ofthe areas and lengths of ‘coastalresources’ by 10 km2




Timeperiod


Comments







Continentalshelf andslope areasaround theBritish Isles(e.g. NorthSea, IrishSea, CelticSea,continentalslope off northwest Scotland)

Continentalshelf andslope areasaround theBritish Isles(e.g. NorthSea, IrishSea, CelticSea)

North WestEuropeanshelf (48oN–63oN, 12oW–13o E)




1968onwards

1974onwards

1982onwards

1987onwards

1989onwards

1970onwards

POL moored currentmeter databank: currentspeed, current direction,also temperature andpressure

POL databank ofCTD/STD profiles:conductivity/salinity,temperature,depth/pressure,occasionally oxygen,transmittance

The POL operationalstorm surge model dataarchive: model output oftidal elevation,horizontal components ofresidual currents

Bathing waterbacteriological surveys:faecal coliforms per 100ml, total coliforms per100 ml, temperature,wind speed anddirection, presence ofoils


Thermosalinigraph data:temperature, salinity,fluorescence andoccasionally soundingslogged with date, time,and position

Electronicstorage

Electronicstorage

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Electronicstorage


A storm surge forecast scheme,based on a model developedand maintained by POL for theMinistry of Agriculture, Fisheriesand Food (MAFF). The presentscheme makes use ofmeteorological data from thelimited area model (LAM), whichruns operationally at the UKMeteorological Office forweather forecasting




Timeperiod


Comments





Solway RiverPurificationBoard (SRPB),now part of theScottishEnvironmentProtectionAgency (SEPA)






Beach andseabedaround theGallowayCreameryoutfall, LochRyan, south-west Scotland

Tay estuary,east coast ofScotland

1985onwards

1967onwards

1893onwards

1987onwards

1987onwards

June 1972(neap andspringtides)

CTD data: pressure,temperature,conductivity, salinity

Moored self-recordinginstrument data. Currentspeed and direction,temperature, conductivity(salinity), pressure

Hydrographic data:pressure (depth),temperature, salinity,(sigma-t), oxygen,phosphate, nitrate,silicate, ammonia,chlorophyll a,phaeopigments,particulate organiccarbon and particulateorganic nitrogen


Invertebratecommunities, particlesize analysis (PSA)

Data from physical andchemical measurements:tide height, currentspeed and direction,water temperature andsalinity, suspendedsediment concentration

Electronicstorage



Paperreports

Paperreports

Hard copy




Twenty-four sampling stations onthe inter-tidal zone of the InnerSolway Firth, betweenDorknockbrow and Arbigland(54°53´ N, 03°11´ W to54°54´’ N, 03°34´ W)

Annual survey of 24 samplingpoints (16 subtidal, eightintertidal) at the head end ofLoch Ryan

A major programme designedso that simultaneous changes invarious physical and chemicalparameters could be measuredthroughout the entire length ofthe Tay estuary. Data werecollected from over 50measuring stations as part ofundergraduate, doctoral andpost-doctoral researchprogrammes



Timeperiod


Comments





Tay Estuary,east coast ofScotland

Dundeeforeshorebetween roadbridge andBroughtyCastle

West ofScotland

Loch Creran,Argyll

1972–1982

1989 and1991

July 1983,February1985,October1987,December1987,February1988

1971–1982

Data from tidal cyclemeasuring stations in theTay estuary, east coast ofScotland: tide height,current speed anddirection, watertemperature, salinity,suspended sedimentconcentration, Secchidisc depths

Fauna, loss-on-ignitionand particle sizeanalysis

CTD and moored currentmeter data collectedduring the ScottishCoastal Currentexperiment: temperature,salinity, current speedand direction


´

Hard copy

Paperreports

Electronicstorage


A major programme designedso that simultaneous changes invarious physical and chemicalparameters could be measuredthroughout the entire length ofthe Tay estuary. Data werecollected from over 50measuring stations as part ofundergraduate, doctoral andpost-doctoral researchprogrammes

827 CTD profiles of temperatureand salinity collected on fivecruises and a series of 71moored current meter datareadings The data from the1987 and 1988 cruises werecollected as part of the ScottishCoastal Current programme andthe Autumnal CirculationExperiment (ACE)



Have your say!Part 7


Natural Heritage Trends: The Seas Around Scotland

What do you think of the report?

StrengthsWhat do you like about the report?

WeaknessesIs there anything you dislike about the report?

UsesHow would you make use of the report?

ImprovementsHow could the report be improved?


What changes to the natural heritage are of most concern to you (from direct experienceor other knowledge)?

In this reportWhat issues in this report concern you most?

ElsewhereWhat are your top (say, five or more) natural heritage concerns?

Please add details about yourself if you wish

Make a copy of the form and return it by post to:

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Visit our web sitewww.snh.org.uk/trends

154 Natural History Trends: Seas Around Scotland 2004

34

Index

Natural History Trends: Seas Around Scotland 200435 156

abyssal zone 8Acartia tonsa 92Agreement on Small Cetaceans of theBaltic and North Seas (ASCOBANS) 37allis shad 21amnesic shellfish poisoning 51angel shark 10, 29Antithamnionella spirographidis 86, 90Antithamnionella ternifolia 90aquaculture 48–51, 108Arctic char 48Arctic skua 42, 43Arctic tern 43, 45Asparagopsis armata 86, 89Atlantic puffin 42, 43, 45Atlantic salmon 10, 48Atlantic white-sided dolphin 34, 36Aulacomya ater 92

Balanus amphitrite 92basking shark 10, 24, 29, 30, 31Bathing Water Directive 71bathing waters

microbiological requirements 114quality assessment 75

Bathing Waters (Classification)(Scotland) Regulations 1991 71bathyal zone 8beam trawl gear 61beluga (white) whale 34Biodiversity Action Plans 10, 24, 68,

105biological and chemical data sources

127–34biological data sources 116–26biological oxygen demand 73black guillemot 43, 45black scabbardfish 65, 66, 67black-headed gull 42, 43black-legged kittiwake 43, 44black-mouthed dogfish 29blonde ray 28blue hake 65blue ling 65, 66, 67blue shark 29blue whale 33, 34, 35blue whiting 65Bonnemaisonia hamifera 86, 89bottlenose dolphin 21, 34, 36bramble shark 29

British Geological Survey 127, 135–6British Oceanographic Data Centre

116, 127–8, 136–9

bycatch 36

Calanus finmarchicus 97Caprella mutica 85, 88, 92cetaceans 33–8chemical poisoning 83climate change 98, 105Clyde estuary 73coastal environment 70–7coastal squeeze 99

coastal waters classification 112cod 47, 54, 58

stocks 57, 59Codium fragile 86, 91cold-water corals 10, 15, 24, 67Colpomenia peregrina 86, 90common dolphin 34, 36Common Fisheries Policy 60common guillemot 43common skate 10, 24, 28, 29common tern 42, 43Conservation (Natural Habitats etc.)Regulations 1994 19Conservation of Seals Act 1970 41continental shelf fisheries 52–64

demersal fish 53ecological changes 60fishing gear 61pelagic fish 53shellfish 53stock assessment 53

Convention on International Trade inEndangered Species of Wild Fauna andFlora 29copepods 97Corophium sextonae 87, 92Crassostrea gigas 93Cromarty Firth Port Authority 139cuckoo ray 28Culterty Field Station 116Cunninghame District Council 116Cuvier’s beaked whale 34

darkie charlie 29Darwin Mounds 19deepwater fish/fisheries 65–8deepwater monkfish 66Defence Research Agency 139demersal fish 8, 53demersal pair trawl gear 61diarrhetic shellfish poisoning 51dogwhelk 75dolphins 21, 33–8

strandings 35, 36dredging 61Dunstaffnage Marine Laboratory

117–18, 128–30, 139–42

eelpout 10, 99egg-wrack 24electric ray 28Elminius modestus 87, 91environment quality 70–7environmental change 95–101

sea temperature change 96sea-level change 96, 97, 99species impacts 100storms 96wave height 97

estuarine environment 70–7estuarine waters classification 113European shag 43, 46European storm-petrel 42, 43, 45European Union Habitats Directive seeHabitats Directive

false killer whale 34fan shell 24fatherlasher 10, 99feral cats, predation of seabirds 45ferrets, predation of seabirds 45fin whale 33, 34, 35fish farming 48–51, 108

salmon 48shellfish 48–9, 50–1, 108

fisheries/fishingcontinental shelf 52–64deep water 65–8shark 31

fishing gear, ecological impact 61, 62fishing mortality 53Forth estuary 73foxes, predation of seabirds 45frilled shark 29

great black-backed gull 43, 45great cormorant 42, 43, 46great skua 43greater forkbeard 65greater silver smelt (argentine) 65Greenland shark 29grey seal 21, 39ground-nesting tern 45Gulf Stream 97

Habitats Directive 15, 17, 19, 106Annex I 20Annex II 21

haddock 54, 58, 59hake 55Haliplanella lineata 87, 91harbour (common) seal 10, 21, 39–41harbour porpoise 21, 34, 37herring 52, 53, 54

stocks 56, 59herring gull 43humpback whale 33, 34, 35

infectious salmon anaemia 50Institute of Oceanographic Sciences

119, 130, 142–3International Council for the Exploration

of the Sea 10International Union for Conservation ofNature and Natural Resources 29International Whaling Commission 33

Joint Cetacean Database 38Joint Nature Conservation Committee

122–3, 146

kestrel 45killer whale 34Kinneil mudflats 74Kyle and Carrick District Council 130

lagoon sea slug 24Leach’s storm-petrel 42, 43, 45leafscale gulper shark 65leathery sea squirt 88lesser black-backed gull 42, 43, 44

157Natural History Trends: Seas Around Scotland 2004

lesser spotted dogfish 29little tern 43, 45littoral zones 8long-finned pilot whale 34, 36long-nosed skate 10, 28Lophelia pertusa 10, 15, 24, 67

mackerel 55, 58, 59maerl 24MAFF Directorate of Fisheries Research

119–22, 130–1, 143–5Manx shearwater 42, 43, 45Marenzelleria viridis 91mariculture 48–51Marine Advisory Service 145Marine Biological Association of the

U.K.122marine conservation 17–25marine litter 78–84, 109

effect on turtles 82impact of 78implications of 81–3waste munitions 80see also pollution

Marine Nature Conservation Review 12Marine Nature Reserves 17marine plankton 97Marine Recorder 16marine species 13

trends in 24marine surveys 14MCS Beachwatch Nationwide BeachClean and Survey Report 13megrim 55Merchant Shipping Act 1995 81Merchant Shipping and MaritimeSecurity Act 1997 81Merchant Shipping (Port WasteReception Facilities Regulations 1997

81Mermaid 16mew (common) gull 42, 43, 44Minch Project 13mink, predation of seabirds 45minke whale 34, 35, 36MNCR see Marine Nature Conservation

ReviewModiolus modiolus 24monkfish 55mora 65Moray Firth 35mussels 48Mya arenaria 87, 93

National Parks and Access to theCountryside Act 1949 17Natural Environment Research Council

41Natural Heritage Futures 104–5Natural History Museum 123Nature Conservation (Scotland) Bill 33non-native species 85–94

harmful 88North East River Purification Board 123,

131–2, 147

roseate tern 43, 44, 45round ray 28roundnose grenadier 65, 66, 67

Sabellaria alveolata 24Sabellaria spinulosa 24St Kilda World Heritage Site 10, 15,

21, 22saithe 54, 59salmon farming 48sandeel 54sandwich tern 43, 45sandy ray 28Sargassum muticum 85, 90scallop 48scaup 72, 74Scottish Association for Marine Science

117–18, 128–30, 139–42Scottish Environment Protection Agency

50Scottish Natural Heritage 17, 50Scottish Office Agriculture and Fisheries

Department 124, 133, 147–8Sea Fish (Conservation) Act 1992 60Sea Fisheries (Wildlife Conservation) Act

1992 60sea lamprey 21Sea Mammal Research Unit 105, 124sea pen 24sea squirt 24sea temperature change 96sea trout 48sea-fan anemone 24sea-level change 96, 97, 99

species impact 100seabirds 42–6

culling 46drowning 46food availability 46ground predators 45pollution 46predation 46

seals 21, 39–41, 105sei whale 33, 34, 35seine netting 61SEPA see Scottish Environment Protection

AgencySEPA coastal waters classification

scheme 112SEPA estuarine waters classification

scheme 113serpulid reef 24sewage sludge dumping 75, 76sewage-related debris 13shagreen ray 28shark fisheries 31sharks 28–32

see also individual speciesshellfish 53

dredging 61farming 48–9, 50–1, 108

shipping 70shore dock 21shortfin mako shark 29shrimp beam trawl 61

northern bottlenose whale 34, 35northern fulmar 42, 43

ingestion of plastic 83northern gannet 24, 43, 44northern hatchett shell 24northern right whale 33, 34, 35northern shrimp 55Norway lobster 55Norway pout 54, 59nuisance species 88nurse hound 29nutrient enrichment 76

Odontella sinesis 89Offshore Marine Conservation

(Natural Habitats, etc.) Regulations 2003 19

orange roughy 65, 66, 67organochlorines 37OSPAR Commission 10, 33, 106otter 21otter trawl gear 58, 61over-fishing 108oyster 24

Pacific oyster 48paralytic shellfish poisoning 51pelagic fish 8, 53phocine distemper virus 39, 105physical data sources 135–49plaice 53, 55, 58

stocks 59plants 21plastic waste 81–3Plymouth Marine Laboratory 123–4,

132, 146pollution

effect on seabirds 46sewage sludge dumping 75, 76shipping-related 70see also environment quality; marine litter

polychaete worm 72Polysiphonia harveyi 90porbeagle shark 29porpoises 21, 33–8

strandings 35, 36Portuguese dogfish 65Potamopyrgus antipodarum 87, 92prawn trawl 61Proudman Oceanographic Laboratory

132, 147purse seine gear 58

queen scallop 48

rats 45rays 28–32razorbill 43recruitment 53ring netting 61Risso’s dolphin 34, 36river lamprey 21River Purification Boards 70Rockall Trough 19

Natural History Trends: Seas Around Scotland 200435 158

UKbenthos database 16United Nations Convention on

Biological Diversity 23United Nations Education, Scientific and

Cultural Organisation (UNESCO) 21University of Wales, Bangor School of

Ocean Sciences 126, 134, 149

waste munitions 80Water Framework Directive 76wave height 97whale shark 28whales 33–8

strandings 35, 36Whaling Industry (Regulation) Act 1934

33white-beaked dolphin 34, 36whiting 54, 59Wildlife and Countryside Act 1981 10,

17, 29, 33

starry skate 28starry smooth hound 29stoats, predation of seabirds 45storms 96stranding 35, 36striped dolphin 34, 36Styela clava 87, 93survey stations 14

Tay River Purification Board 125–6, 133–4, 148–9

Thalassiosira punctigera 89Thalassiosira tealata 89thornback ray 28thresher shark 29tope 29tourism 12tributyltin 75, 109trout 50True’s beaked whale 34turbot 48turtles, effect of marine litter on 82tusk 65twaite shad 21twin trawl gear 61

Sir Alister Hardy Foundation for Ocean Science 125

Sites of Special Scientific Interest 17, 19, 22, 23

six-gilled shark 29skates 28–32skeleton shrimp 85, 88, 92skua 42slipper limpet 88smooth hound 29sole 55, 59Solway River Purification Board 125,

133, 148Sowerby’s beaked whale 34spawning stock levels 53Special Areas of Conservation 17, 18,

19Special Protection Areas 17Species Biodiversity Action Plan 29species diversity 105sperm whale 33, 34, 35, 36spotted ray 28sprat 55spurdog 29

Working with Scotland’s people to care forour natural heritageScottish Natural Heritageis a government body responsible to the Scottish Executive and Scottish Parliament.

Our mission statement is:Working with Scotland’s people to care for our natural heritage.

Our aim is:Scotland’s natural heritage is a local, national and global asset. We promote itscare and improvement, responsible enjoyment, greater understanding andappreciation, and sustainable use now and for future generations.

Our operating principles are:We work in partnership, by co-operation, negotiation and consensus, wherepossible, with all relevant interests in Scotland: public, private and voluntaryorganisations, and individuals.

We operate in a devolved manner, delegating decision-making to the local levelwithin the organisation to encourage and assist SNH to be accessible, sensitiveand responsive to local needs and circumstances.

We operate in an open and accountable manner in all our activities.

Further informationfurther copies of this reportare available fromScottish Natural HeritagePublications SectionBattlebyRedgortonPerth PH1 3EWt: 01738 444177t: 01738 458613e: [email protected]: www.snh.org.uk/trends

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Natural Heritage TrendsThe Seas Around Scotland

2004

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