Matthew ServiceMatthew Service

• Anthropogenic PressuresAnthropogenic Pressures

Principal PressuresPrincipal Pressures

• Physical disturbance from direct impacts Physical disturbance from direct impacts and resulting from morphological changesand resulting from morphological changes

• Contaminants; Heavy metals and OrganicContaminants; Heavy metals and Organic

• NutrientsNutrients

Stresses on the environmentin form of direct pressuressuch a emmissions, riverine& direct inputs

Catchment

Area

(km2)

Length

(km)

Maximum

Width

(km)

Surface

Area LW

(km2)

Surface

Area HW

(km2)

Max.

Depth

(m)

Volume

(106 m3)

Coastline

(km)

771.5 30.0 8.0 106.2 182.8 66.0 1 251.5 240.0

Catchment AreaUrban-

IndustrialIndustrial

Arable GrassRoughgrazing

ForestOtherland

km2 % of area

Strangford 588 5.2 8.0 84.2 0.1 1.8 0.7

Residual near surface circulation

Potential energy anomaly (J m3) and drifter tracks

1. Introduction

Time lineTime line

• 1857 Dickie reports presence of 1857 Dickie reports presence of M modiolus M modiolus in in Lough:Lough:

• oysters in “central area”oysters in “central area”

• cf 1900 Oyster fishery declines:cf 1900 Oyster fishery declines:

• cf 1930 Spartina introduced;cf 1930 Spartina introduced;

• Boyd (1969) describes plankton and water quality;Boyd (1969) describes plankton and water quality;

• Jenkinson(1974) Describes hydrodynamicsJenkinson(1974) Describes hydrodynamics

• 1970 first reports of Queen Scallop trawling:1970 first reports of Queen Scallop trawling:

• Erwin 1977 Describes S Lough BenthosErwin 1977 Describes S Lough Benthos

• Roberts 1975 Describes Roberts 1975 Describes M modiolus/Chlamys M modiolus/Chlamys varia varia community;community;

• 1978 Spartina spraying started;1978 Spartina spraying started;

• 1979 Parker report on shellfish contaminants 1979 Parker report on shellfish contaminants forerunner of Musselwatch study;forerunner of Musselwatch study;

• 1984 Investigation in double shelling and 1984 Investigation in double shelling and links with TBT;links with TBT;

• 1984 1984 SpartinaSpartina spraying implicated as cause spraying implicated as cause of sediment release;of sediment release;

• Late 1980’s Queen Scallop trawling expands;Late 1980’s Queen Scallop trawling expands;

• 1985 Ardmillan Bay designated under EC Shellfish Waters 1985 Ardmillan Bay designated under EC Shellfish Waters Directive;Directive;

• 1989 Brown publishes report claiming trawling is 1989 Brown publishes report claiming trawling is destroying destroying M modiolus M modiolus communities;communities;

• 1990 DOE(NI) Commission Mathematical Model 1990 DOE(NI) Commission Mathematical Model

• 1990 ISD report confirms trawling having impact;1990 ISD report confirms trawling having impact;

• 1993 DANI(DARD) introduces fishing restrictions;1993 DANI(DARD) introduces fishing restrictions;

• 1993 DARD report on sediment metals1993 DARD report on sediment metals

• 1995 Possible introduction of Sargassum1995 Possible introduction of Sargassum

• 1996 Magorrian Thesis on Effects of commercial trawling 1996 Magorrian Thesis on Effects of commercial trawling (DARD studentship);(DARD studentship);

• 1997 1997 Spartina Spartina spraying resumed;spraying resumed;

• 1997 DARD project on Recovery of benthic 1997 DARD project on Recovery of benthic communities project initiatedcommunities project initiated

• DARD/EHS report on Trophic Status of LoughDARD/EHS report on Trophic Status of Lough

• 1998-2000 Further DARD Report on Sediment 1998-2000 Further DARD Report on Sediment ContaminantsContaminants

• 1999 Sea defence reconstruction begun at 1999 Sea defence reconstruction begun at Newtownards;Newtownards;

• 2001 Release of sediment from Killyleagh 2001 Release of sediment from Killyleagh foreshore;foreshore;

• EutrophicationEutrophication

• Trace Contaminants (Heavy metals and Trace Contaminants (Heavy metals and organics) in sediments;organics) in sediments;

• Shellfish contaminants;Shellfish contaminants;

• Physical disturbance;Physical disturbance;

• Algal toxins:Algal toxins:

Routine MonitoringRoutine Monitoring

• EC Shellfish Waters DirectiveEC Shellfish Waters Directive

• EC Shellfish Hygiene DirectiveEC Shellfish Hygiene Directive

• National Marine Monitoring Plan (OSPAR National Marine Monitoring Plan (OSPAR JAMP)JAMP)

• EHS Estuarine ClassificationEHS Estuarine Classification

Water Quality:Water Quality:• DARD/QUB AESD conducted a spatial and temporal survey DARD/QUB AESD conducted a spatial and temporal survey

of nutrient loading to the lough and nutrients, phytoplankton of nutrient loading to the lough and nutrients, phytoplankton

and chlorophyll in the lough over the period 1993-1996and chlorophyll in the lough over the period 1993-1996..• EHS estuarine class programme collects limited low EHS estuarine class programme collects limited low

frequency nutrient and plankton data.EHS also monitor frequency nutrient and plankton data.EHS also monitor heavy metals in water as part of the EC Shellfish Waters heavy metals in water as part of the EC Shellfish Waters monitoring .monitoring .

• DARD- AESD analyse samples from active shellfish sites for DARD- AESD analyse samples from active shellfish sites for presence of toxic algae fortnightly. This is reported annually.presence of toxic algae fortnightly. This is reported annually.

• EHS-EP report input data from Ballyrickard STW, Killyleagh EHS-EP report input data from Ballyrickard STW, Killyleagh STW and Downpatrick STW.- the Quoile.STW and Downpatrick STW.- the Quoile.

Loads(KG)

0

500

1000

1500

2000

2500

CA

DM

IUM

GA

MM

A-

ME

RC

UR

Y

PC

B 118

PC

B 153

PC

B 28

ZIN

C T

OT

AL

Loads(KG)

OSPARCOM Loading Data

Nutrient Drivers:Nutrient Drivers:

• EC UWWT DirectiveEC UWWT Directive

• EC Nitrates DirectiveEC Nitrates Directive

• Eutrophication Eutrophication is defined by the EC (in the is defined by the EC (in the Urban Waste Water Treatment DirectivUrban Waste Water Treatment Directive) as:e) as:

• the enrichment of waters by nutrients, the enrichment of waters by nutrients, especially compounds of nitrogen especially compounds of nitrogen and/orphosphorus, causing an accelerated and/orphosphorus, causing an accelerated growth of algae and higher forms of plant life growth of algae and higher forms of plant life to produce an undesirable disturbance to the to produce an undesirable disturbance to the balance of organisms present in the water balance of organisms present in the water and to the quality of the water concernedand to the quality of the water concerned

• Taylor and Service (1998)concludedTaylor and Service (1998)concluded

• Irish Sea is the largest source of nitrogen, Irish Sea is the largest source of nitrogen, phosphate and silicate loading to Strangford Loughphosphate and silicate loading to Strangford Lough

• The total annual anthropogenic load of DIN and SRP The total annual anthropogenic load of DIN and SRP (excluding the Irish Sea and airborne deposition) to (excluding the Irish Sea and airborne deposition) to

the Lough are 1 201 and 116 tonnes, respectivelythe Lough are 1 201 and 116 tonnes, respectively;;

• Eutrophication Eutrophication is defined by the EC (in the is defined by the EC (in the Urban Waste Water Treatment DirectivUrban Waste Water Treatment Directive) as:e) as:

• the enrichment of waters by nutrients, the enrichment of waters by nutrients, especially compounds of nitrogen especially compounds of nitrogen and/orphosphorus, causing an accelerated and/orphosphorus, causing an accelerated growth of algae and higher forms of plant life growth of algae and higher forms of plant life to produce an undesirable disturbance to the to produce an undesirable disturbance to the balance of organisms present in the water balance of organisms present in the water and to the quality of the water concernedand to the quality of the water concerned

Figure 41 : Sources of Summer (August) DIN Loads

EstuarineSTWs61%

Rivers30%

Direct Runoff9%

Total Monthly Load = 27.60 Tonnes

a.

Figure 41 : Sources of Winter (January) DIN Loads

EstuarineSTWs

6%

Direct Runoff34%

Rivers60%

Total Monthly Load = 218.00 Tonnes

b.

-5 .7 0 -5 .6 5 -5 .6 0 -5 .5 5 -5 .5 0 -5 .4 5

L o n g itu d e W

54.25

54.30

54.35

54.40

54.45

54.50

54.55

Lat

itud

e N

Heavy MetalsHeavy Metals

• Killyleagh outfall generated more than 10 tonnes of chromium Killyleagh outfall generated more than 10 tonnes of chromium per per annumannum, although during the early 1990s, declined to nearer 1 tonne , although during the early 1990s, declined to nearer 1 tonne per annumper annum;;

• The high mercury concentration in mussels from Whiterock were The high mercury concentration in mussels from Whiterock were similar to those found in mussels from the Inner Forth estuary in similar to those found in mussels from the Inner Forth estuary in Scotland (Davies and Pirie 1980 in Gault Scotland (Davies and Pirie 1980 in Gault et al.et al. 1983) ; 1983) ;

• TBT Implicated in double shelling in oysters;TBT Implicated in double shelling in oysters;

TBTTBT

• Routine monitoring for Imposex and Routine monitoring for Imposex and Intersex in Dogwhelks and Winkles by Intersex in Dogwhelks and Winkles by EHS has shown little sign on effect;EHS has shown little sign on effect;

• Edwards (2002) Suggested that Imposex Edwards (2002) Suggested that Imposex records in Whelks show a reduction in records in Whelks show a reduction in TBT levels.TBT levels.

Sediment QualitySediment Quality• In 1990 approximately 30 samples were analysed at the In 1990 approximately 30 samples were analysed at the <63um particle size level using an aqua regia digest<63um particle size level using an aqua regia digest

• In 1996 a smaller numbers of stations were sampled and In 1996 a smaller numbers of stations were sampled and analysed for heavy metals at the <2mm particle size level analysed for heavy metals at the <2mm particle size level using an HF digest for geochemical normalisation.using an HF digest for geochemical normalisation.

• Hydrocarbons (PAH’s) a spatial survey was carried out in Hydrocarbons (PAH’s) a spatial survey was carried out in 2000 at again about 12 sites.2000 at again about 12 sites.

• DARD have one NMMP sediment station in the Lough that is DARD have one NMMP sediment station in the Lough that is sampled for heavy metals, pesticides, PAH’s.sampled for heavy metals, pesticides, PAH’s.

• EHS –EP have sediment sampling sites(4?) in the lough as EHS –EP have sediment sampling sites(4?) in the lough as

part of their Estuarine Classification Monitoringpart of their Estuarine Classification Monitoring

5.7 5.65 5.6 5.55 5.5 5.45 5 4 . 2

5 4 . 2 5

5 4 . 3

5 4 . 3 5

5 4 . 4

5 4 . 4 5

5 4 . 5

5 4 . 5 5

5 4 . 6

SL3

SL2

SL4 SL5

SL6

SL7

SL8

SL9

SL10

SL11

SL13

SL14

SL15

SL12

SL1

Newtownards

Quoile

Comber

• Service (1993) concluded that with the exception of Service (1993) concluded that with the exception of chromium and mercury, all other metals show strong chromium and mercury, all other metals show strong co-correlation and are therefore from a common, co-correlation and are therefore from a common, geochemical weathering source. By contrast, geochemical weathering source. By contrast, chromium and mercury are most likely to originate chromium and mercury are most likely to originate from the point source outfall at Killyleaghfrom the point source outfall at Killyleagh. .

0

50

100

150

200

250

0 2 4 6 8

Al (%)

Zn

(µ

g g

-1)

NWIS

Belfast

Strangford

2. Trace metal contamination

•

Irish Sea Sites

Sediment Metals 2000

0

20

40

60

80

100

120

140

160

180

NMP4 nmp5 38a NMp3 s lough

AL

Cu

PB

NI

Zn

AS

CR

B

0

50

100

150

200

250

300

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

KillyleaghKirrcubbinPaddys PointNewtownardsQuoileMean

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

Killyleagh

Kirrcubbin

Paddys Point

Newtownards

Quoile

Mean

Heavy Metals in Modiolus modiolus

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

Ag Cd Cr Cu Fe Hg Ni Pb Zn As

Donaghadee

S Lough

*10

*10

• Physical disturbance due to:Physical disturbance due to:

• Trawling or dredging;Trawling or dredging;

• Sediment relocation: Sediment relocation:

• Release of sediment or changes in Release of sediment or changes in coastal cellcoastal cell

• change in prevailing windchange in prevailing wind

Otter Boards or trawls hold the net open and may impact the sea bed

Sediment plumes may help “herd” fish

Tickler chains banned in Strangford Lough

• The worst damage caused by otter boardsThe worst damage caused by otter boards

• The area between scars showed no The area between scars showed no textural differencestextural differences

• area effects has a characteristic texturearea effects has a characteristic texture

2002

7% C.Papposus9% M.Rugosa

28% E.Esculentus

27% A.rubens

28% L.Depurator

1.5% B.Undatum0.5% C.Maenas

Side-scan sonar survey areaSide-scan sonar survey area

• Strangford is subject to variety of Strangford is subject to variety of pressurespressures

• arising both from the catchment and arising both from the catchment and directlydirectly

• there is no evidence that the Lough is there is no evidence that the Lough is eutrophic or heavily contaminatedeutrophic or heavily contaminated

• trawling can impact seabed communitiestrawling can impact seabed communities