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Aquaculturetechniquesandtechnology:

MarineandFreshwaterenvironments

DrWendyFernandes

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Acknowledgements

ThisprojectwouldnothavebeenpossiblewithoutthegenerosityoftheFarmersClub,whofunded

mytripstoHungary,Norway,andSparsholtCollege,throughtheirCharitableTrustEducatorsAward.

IwouldliketothankmyhostsMátéHavasiatHAKI,Hungary,SynnøveHellandatNOFIMA,Norway,

andAdrianLoveatSparsholtCollege,UKforthewarmwelcometotheirinstitutesandfordedicating

somuchoftheirtimetohelpmedevelopmyknowledgeinaquaculturesystemsandmethods.I,and

mystudentsareindebtedtoyou.

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TablesofContents

TableofContents………………………………………………………………………………………………………………………. 3

ListofFigures…………………………………………………………………………………………………………………………….. 4

1.Introduction…………………………………………………………………………………………………………………………… 6

1.1Theaquacultureindustry…………………………………………………………………………………………. 6

1.2Aimofmystudy/objectives ……………………………………………………………………………………. 6

2.AquacultureSpecies………………………………………………………………………………………………………………. 7

2.1NorthAfricancatfish(Clariasgariepinus)(FRESHWATER)……………………………………….. 7

2.2CommonCarp(Cyprinuscarpio)(FRESHWATER)…………………………………………………….. 8

2.3.Atlanticsalmon(Salmosalar)(MARINE)………………………………………………………………... 9

3.TriptoHungary………………………………………………………………………………………………………………………. 10

3.1AquacultureinHungary……………………………………………………………………………………………. 10

3.2HAKI…………………………………………………………………………………………………………………………..10

3.3.RecirculatingAquacultureSystem(RAS):closedindoorsystem………………………………. 11

3.4.AfricanCatfishFarm………………………………………………………………………………………………….14

3.5.CarpFarm…………………………………………………………………………………………………………………16

3.6.ResearchexperimentsatHAKI………………………………………………………………………………… 18

4.TriptoNorway……………………………………………………………………………………………………………………….. 19

4.1AquacultureinNorway…………………………………………………………………………………………….. 19

4.2NOFIMA……………………………………………………………………………………………………………………..19

4.3.SalmonHatchery……………………………….………………………………………………………………………20

4.4Juvenilesalmonfoodtrails…………………………………..…………………………………………………….21

4.5ProcessingFish…….…………………………………………………………………………………………………… 16

4.5RecirculatingAquacultureSystem……………………………………………………………………………. 23

4.6Salmonfishfarm………………………………………………………………………………………………………. 24

5.Aquaculturecoursedesign………………………………………………………………………………………………………28

5.1VisittoSparsholtCollege……………………………………………………………………………………………28

5.2AquaculturelecturesatWrittle………………………………………………………………………………... 28

5.3Aquaculturelecturesamples………………………………………………………………………………...... 29

6.Conclusion……………………………………………………………………………………………………………………………….30

References………………………………………………………………………………………………………………………………….32

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ListofFigures

Fig.2.1NorthAfricancatfish(Clariasgariepinus)

Fig.2.2Africancatfishstockedathighdensity

Fig.2.3MainproducercountriesofNorthAfricancatfish(C.gariepinus)

Fig.2.4CommonCarp(Cyprinuscarpio)

Fig.2.5Farmedcommoncarp

Fig.2.6Mainproducercountriesofcommoncarp(C.carpio)

Fig.2.7Atlanticsalmon(Salmosalar)

Fig.2.8MainproducercountriesofAtlanticsalmon(Salmosalar)

Fig.2.9FarmedAtlanticsalmonsteak

Fig.3.1Hungary,showingthelocationoftheresearchstationandcarpfarm

Fig.3.2TheRecirculatingAquacultureSystem(RAS)atHAKI,Hungary

Fig.3.3TankscontainingAfricancatfishstockedathighdensity

Fig.3.4Meshfilterdrum

Fig.3.5Biofiltertank,HAKI

Fig.3.6Biofiltercloseup,HAKI

Fig.3.7RAScontrolpanel

Fig.3.8Africancatfishfarm,enclosureshousesize-specificfish

Fig.3.9TricklingtowerisinstalledtoremoveCO2fromthewater

Fig.3.10Sortingarangeofmarketable-sizedfishintocrates

Fig.3.11Wastesedimentisdrawnoutfromthewater

Fig.3.12Catfishoutdoorenclosure

Fig.3.13Outdoorrearedfish:ControlledFeeding

Fig.3.14162hectaresofpondareaproducing300tonsoffishperyear

Fig.3.15Grainfeed

Fig.3.16Boatusedtodistributegrain

Fig.3.17Outdoorcarpfeedingexperiment

Fig.3.18Oxbow.Watercompositionstudysite

Fig.4.1Norway,showingthelocationoftheresearchstationandsalmonfarm

Fig.4.2Salmonhatcherytankwithartificialgravel

Fig.4.3Salmonhatcherytankswithpipes

Fig.4.4Salmonhatcherytankwithownwatersupply

Fig.4.5SalmonfeedingtrialsI

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ListofFigurescontinued

Fig.4.6SalmonfeedingtrialsII

Fig.4.7Kinshipstudies

Fig.4.8Processingunit

Fig.4.9Re-circulatingAquacultureSystem(RAS),NOFIMANorway

Fig.4.10Re-circulatingtanks

Fig.4.11HighspeedboattoHitra

Fig.4.12Indoorsalmonhatcheryfarm

Fig.4.13Biofiltertank,Hitra

Fig.4.14Biofiltercloseup,Hitra

Fig.4.15Outdoorseacage

Fig.4.16SeaLice

Fig.4.17SeaLicewarmwatertreatment

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1.INTRODUCTION

1.1Theaquacultureindustry

Aquacultureisafastexpandingfarmingindustryandispracticedbysomeofthepoorest

farmersindevelopingcountries,andbymultinationalcompanies(FAO,2017).Arangeoffreshwater

andmarinefisharecultivated,aswellasshellfish,andaquaticplants.Farmingtechnologytosuit

bothfreshwaterandmarineaquaticlifeisevolvingconstantlyandnewdevelopmentsintheRe-

circulatingAquacultureSystem(RAS)andtheareaofaquaponicsarebeinginvestigated.Thisisto

ensurewecanachieveasustainablefutureforfishfarming,botheconomicallyandenvironmentally.

AspartofmytravelgrantIvisitedHAKI,aresearchinstituteinHungarytolearnabout

freshwaterfishfarmingandthetechnologiestheyusetokeepcostslowandincreaseyields.Ialso

visitedtwofreshwaterfishfarmswhileIwasinHungary;Szarvas-FishKft,aNorthAfricancatfish

farm,andHortobágyiHalgazdaságZrtwhichisacommoncarpfarm.Itwasaneye-openertosee

bothspeciesoffishstockedintanksatsuchhighdensities,withlowmortalityrates.Ialsovisited

NOFIMA,aresearchinstituteinNorwaytolearnaboutmarinefishcultivation.TheRe-circulating

AquacultureSystem(RAS)technologybeinginvestigatedformarinefishishighlysophisticatedand

requiresahugeamountofspaceandstaffarehighlyexperiencedanddedicatedtotherunningof

thesystems.Iwasabletospeaktostaffworkinginthebiologicalandgeneticsideoffishfarming;

investigatingbreedingtechniquesandfishdeformities.Ialsovisitedoneverylargemarinefishfarm

whileIwasinNorway;LerøyBelsvik,anAtlanticsalmonfarminHitra.Thesheersizeofthefishfarm

andthesophisticatedtechnologywasbreath-taking.Thecontrolofdiseasewasalsovery

interesting.

MytravelgrantalsoenabledmetovisitSparsholtCollegeinWinchester,UKwherean

aquaculturecourseiscurrentlyrunning.Iwaskeentounderstandthecoursestructureand

investigatewhetherIcouldpotentiallycreateandrunsuchaprogrammeatWrittleUniversity

Collegeinthefuture.IwasveryimpressedwiththeaquaculturefacilitiesatSparsholtCollegeand

theexpertiseofthelecturersdeliveringthecourse.

1.2Aimofmystudy/objectives

• Tospeaktotheworldleadingexpertsinaquacultureresearchandlearnaboutthe

expandingareaoffishfarminginbothfreshwaterandmarineenvironments

• Toexplorethenewsustainabletechnologiesthatarebeingimplementedworldwide

• ToinvestigatethepotentialforcreatinganaquaculturecourseatWrittleUniversityCollege

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Fig.2.2AfricancatfishstockedathighdensitySource:AgriFarming

Fig.2.3.MainproducercountriesofNorthAfricancatfish(C.gariepinus)

2.AQUACULTURESPECIES

2.1NorthAfricancatfish(Clariasgariepinus)(FRESHWATER)

NorthAfricancatfish(C.gariepinus);simplyreferredtoas

‘Africancatfish’(Fig.2.1)isafreshwaterfishwithapan-

Africandistribution.Theyarealsonativetothestreamsin

JordanandIsrael,anditisanintroducedspeciestosome

riversofTurkey(FAOFactsheet).Thefishhaveslendereel-

likebodies,withflatbonyheadsandfourpairsofbarbels.

Africancatfisharefoundinlakes,streams,rivers,swamps

andfloodplains,manyofwhichhavelowwaterlevelsor

aresubjectedtodryinginhotmonths.Accordingtothe

IUCN(2017),itisnotathreatenedspecies.

TheAfricancatfishishighlyresilienttodiseases

(Edwardetal.,2010),andhasaccessorybreathing

organswhichallowittosurviveduringdry

seasons(FAOFactsheet1),andduringmytripto

HungaryIobservedthatstockingdensitywasso

highthatthewaterwasbarelycoveringthefish.

Thefisharenaturallyadaptedtolivecomfortably

duringdraughtswhenwaterisscarce(Edwardet

al.,2010),andthisalsoenablesfishfarmerstouse

lesswaterwhichismuchmorecosteffectiveandenvironmentallyfriendlier.Africancatfishare

consideredtobeoneofthemostimportantandsoughtaftertropicalfreshwaterfishspecies,

producinghighyieldsintheaquacultureenvironment(DadaandWonah,2003).C.gariepinushasa

highfecundityrate,tolerateshighstockingdensities(Fig.2.2)alongwithenvironmentalextremes,

andacceptsavarieddietofbothnaturalandartificialfood(Bruton,1979).

Fig.2.1NorthAfricancatfish(Clariasgariepinus)

Source:Life.In.A.Tank

Nigeriaisbyfarthelargestproducerofcatfish

accordingtoFAOstatistics,buttheNetherlands,

Hungary,Kenya,theSyrianArabRepublic,Brazil,

Cameroon,MaliandSouthAfricaalsoproduce

significantvolumes(Fig.2.3)(FAO,2017).Manylocal

recipesinAfricanregionsusecatfishspeciesin

soups,curriesandstews,andinsoutheastAsia

catfishisoftendeepfriedandservedriceandsalad.

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Fig.2.6.Mainproducercountriesofcommoncarp(C.carpio)

Source:FAO,2017

2.2.CommonCarp(Cyprinuscarpio)(FRESHWATER)

Commoncarp(Cyprinuscarpio)(Fig.2.4)area

brownish-greencolouronthebackanduppersides,

andaregoldenventrally.Theyhaveanelongated

andcompressedbody,andthicklips(FAOFactsheet

2).Thecommoncarphasonelongdorsalfinwith

hardandsoftrays.Theyarefoundinalarge

temperaturerangeof3-35C,andtheoptimalwater

temperatureforgrowthisbetween20–25oC(Froese

andPauly,2011).AccordingtoFreyhofandKottelat

(2008),wildcommoncarparelistedas‘vulnerable’,andthismaybeduetoriversdryingout.

Althoughcarpprefertoliveinshallowwaters,theyrequirefloodedareastospawn.Commoncarpin

thewildnormallyfeedonworms,snailsandinsects.TheyaredistributedinEuropeanlakesand

rivers,howeverithasbeenwidelyintroducedtoNorthAmerica,SouthernAfrica,NewZealand,

AustraliaandAsia.Inthewild,commoncarpliveinsectionsofriverswherethewaterisshallow(just

afewmetersdeep)andwherethesubstrateismuddy(FAOFactsheet2).

Commoncarp(Fig.2.5)isthethirdmost

widelyproducedfreshwaterfishspeciesin

theworld(FAO,2013),aftergrasscarpand

silvercarp.Commoncarpisrarely

producedintanksorcagesowingtothe

lowervalueofcarpitselfandthehighcosts

inobtainingprotein-richfoodslikeworms

andsnails.Therefore,mostcommercially

farmedcarpisproducedinfishpond

systems,andthisismuchmorecost

effectiveforproducers(FAO,2013).

Asiaaccountsformorethan90%ofcommoncarp

aquacultureproduction(Fig.2.6),andChinaalone

contributed77%oftheworld’saquacultureproduction

ofcommoncarpin2009(FAO,2013).Carpisoften

deepfried,orbakedandservedwithlemonandchips.

Fig.2.4CommonCarp(Cyprinuscarpio)

Source:DepartmentofPrimaryIndustries

Fig.2.5.FarmedcommoncarpSource:Flickr

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Fig.2.8MainproducercountriesofAtlanticsalmon(Salmosalar)Source:FAO,2017

2.3.Atlanticsalmon(Salmosalar)(MARINE)

TheAtlanticsalmon(Salmosalar)(Fig.2.7)hasalaterally

compressedbodyformanddorsaladiposefin(Webbetal.,

2007).Atlanticsalmonspendtheirjuvenilelifeinrivers.

Thosethatareanadromouswillmigratetosea,andlater

returnasadultstotheirnatalstreamtospawn.Inmany

rivers,thespeciesisalreadyextinct(IUCN,2017).Itsdemise

canlargelybeattributedtohumanactivities,yet

paradoxicallyitremainsabundantowingtoitsimportance

tohumansasasuccessfulaquaculturespecies(Verspooretal.,2007).ExistingwildstocksofAtlantic

salmonaredistributedaroundtheeastcoastofNorthAmerica,EuropeandBalticregions.

Mostoftheresearchintosalmonfarmingis

undertakeninNorthernEuropeanproducingcountries

(Fig.2.8),andtendstofocusondevelopingeconomies,

reducingunitproductioncosts,andprotectingprofit

margins.Itseemslikelythatfutureproductionsurges

willoccurinChile,wherecostsofproductiontendto

belower,owingtolowercostoflabourandraw

materials(FAO,2017).Diseasesusceptibilityisamajor

problemforAtlanticsalmonfarmers.Infact,itcanbe

thecauseofveryhighmortalityratesintheaquacultureenvironmentatallstagesofthesalmonlife

cycle.Manyresearchgroupsareinvestigatinggeneticresistancetodiseases,vaccines,andeffective

breedingprogramstoincreaseproductivity.

Fig.2.7.Atlanticsalmon(Salmosalar)

Source:SeaMaxGlobal

Fig.2.9FarmedAtlanticsalmonsteak.Thefleshtendstobefattier

andpalerthanwildsalmonSource:atlanticcanadaexports

Thefarmedsalmonindustryhasgrownsignificantlyinthelast40years;

todayaround60%oftheworld’ssalmonproductionisfarmed(Global

SalmonInitiative,2017).Morethan2,200,000tonsoffarmedsalmon

wereproduced2015,incomparisontoaround880,000tonsofwild-

caughtsalmon(MarineHarvest,nodate).Thelargestmarketsforfarmed

AtlanticsalmonareJapan,theEuropeanUnion,andNorthAmerica(FAO,

2017),andaresoldfresh(Fig.2.9)andfrozen.Bakedsalmonisapopular

dishinEuropeandAmerica,butitiscommontoseesalmoneatenrawas

partofasushidishinAsiancountries.

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Fig.3.1Hungary,showingthelocationoftheresearchstation(lowercircle)andcarpfarm(uppercircle).Source:TES

3.TRIPTOHUNGARY

3.1AquacultureinHungary

Hungaryisalandlockedcountry(Fig.3.1),andisknownforitslong-standingtraditionoffish

farming.ThefirstfishfarmsinHungarywereestablishedinthe1890s.Thegeographical,waterand

climaticconditionsinHungaryarefavourablefortraditionalpondfishhusbandry.Pondaquaculture

isbenefitedbythesheervolumeofhighlyexperiencedprofessionalswhohavepassedknowledge

downtogenerationsforcenturies.Also,Hungaryisfortunatetoreceiverichgeothermalwater,

whichreducedenergydemandsandcanalsobeusedtosupportarangeofexoticspecieswithhigh

exportpotential.Theseexoticspeciesareresilientandthriveinrecirculationsystems(European

Commission,2017).

Hungarianaquaculturepossessessomespecialcharacteristics,forexample,itsworldwide

reputationincarpbreeding.ThetotalareacoveredbyfishpondsinHungaryisapproximately28,000

hawiththemajorityspeciesfarmedbeingcommoncarp(Cyprinuscarpio).Hungary’scarp

productionisthethirdlargestinEuropeandrepresents74%ofthetotalfishproductioninHungary.

Morethan10%ofproductioncomesintensivefishfarmingofmainlyEuropeancatfish,sturgeon

species,andsomepikeperch.Around7%ofproductioncomesfromgeothermalintensivewater

systems,inwhichthemajorspeciesfarmedistheNorthAfricancatfish(Clariasgariepinus)(FAO,

2017).

3.2HAKI

ManyareasofresearchcarriedareoutatHAKI;Aquaculturesystemdevelopment,fish

nutrition,immunology,fishbiology,freshwaterfisheries,genetics,andwaterecology.Current

projectsincludegenotypingandmaintainingliveandfrozenfishgenebanks,andinvestigating

thepreventionandtreatmentsoffishdiseases.Someofthefirstexperimentsinvestigatingthe

growthrateandlarvalrearinginAfricancatfishwereconductedatHAKIinthe1980s.

ResearchersattheinstitutealsofoundthatPikeperchgrowfasterinintensiveindoorconditions

ascomparedwithlessintensive,outdoorpondrearing.

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3.3.RecirculatingAquacultureSystem(RAS):closedindoorsystem

IwasveryhappytobeabletoseeaRecirculatingAquacultureSystem(RAS)duringmytrip

toHAKI.Itisamazinghowanentirefishproductionsystemcanexistinjustonelargeareaandbe

controlledverysimply.Thetanksinthissystemcontainedcommoncarp,grasscarpandsterlet(Fig.

3.2),andoftenattractedvisitingfarmersfromAfricancountriestoseethesetupandlearnhowto

developtheirownsystems.Thefarmconsistsoftankscontainingwaterandthefishwhicharefedby

thefarmers(Fig.3.3).Thewateriscloselymonitoredsothatoxygenlevelsmaybemaintainedat

safelevels.EquipmenttodissolveO2isinstalledoutsideeachtank.Thecatfisharestockedatahigh

densityandIwasabletoobservethembeingfed.

Fig.3.2TheRecirculatingAquacultureSystem(RAS)atHAKI,Hungary

Fig.?.TankscontainingAfricancatfishstockedathighdensityFig.3.3Tankscontainingcommoncarp,grasscarp,andsterletstocked

athighdensity

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ThewholesetupoftheRASisfascinating.Sinceitisarecirculatingsystem,avastmajorityof

waterisreused,thereforeitneedstobecleanedaftereachcylce.Asmallfractionofwaterislost

aftereachcyclethroughbio-filteringandremovalofwaste,thereforeasmallfractionofwateris

addedtothetanksineachcycle.Thecyclestartswiththewaterinthetanks(Fig.3.3)containingthe

fish.Thewaterthenleavesthetanksandpassesthroughameshfilterdrumtoremovelargewaste

particles(Fig.3.4).Oftenthiswasteproductcanbeusedasafertiliserforplantsoraquaponics

systems.Oncethewaterhaspassedthroughthemeshfilter,itthenenterstankswhichcontain

biofilters(Fig.3.5).

Fig.3.4Meshfilterdrum

Fig.3.5Biofiltertank,HAKI

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Thesebiofiltersarelookalittlebitlikepastashapestome!(seeFig.3.6).Thebiofiltersare

placedintoacompartmentinwhichwaterwhichhaspassedfromthefirstdrumfilter,tobefiltered

againviathebiofiltrationsystem.Thisiswheretoxinsareremovedfromthewaterbeforeentering

thefishtankswheretherecirculatingwatercyclestartsagain.

ThewholeRASiscontrolledbyapanelinstalledbythedoor(Fig.3.7)sothatfarmersdonotneedto

enterfarintothefarm,thusreducinganyriskofcontamination.

Fig.3.6Biofiltercloseup,HAKI

Fig.3.7RAScontrolpanel

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Fig.3.9TricklingtowerisinstalledtoremoveCO2fromthewater

Fig.3.8Africancatfishfarm,enclosureshousesize-specificfish

3.4.AfricanCatfishFarm(Szarvas-FishKft)

TheAfricancatfishfarm(Szarvas-Fish)I

visitedisoneoftwosites.Africancatfishat

thefarmarehousedinenclosureswhich

supportspecificsized-rangedfish.Theyare

fedwithpellets,andthewaterisnot

recirculated(Fig.3.8).Thepropagation

methodsandhatcheryprocessestakeplace

attheothersite.Propagationtakesplace4-

5timesayear.Thefisharriveatthissiteat

around40-50g.Therearedifferentsize

groupsrangingfromaround50gto3-4kg,

hencethenumberofdifferentenclosures

seeninFig.3.8.

Thewaterissourcedbynaturallyoccurring

thermalsprings,andtricklingtoweris

installedtoremoveCO2fromthewater(Fig.

3.9).Thewatertemperatureisaround22-

28C.Ittakes11monthsfromthelarvaestage

tomarketsizewhichisaround1.5–2.5kilos.

Cannibalismiscommon,butonlyatthe

juvenilestage.Survivaloflarvaeis20%,but

thesurvivalofadultsis90-95%.Around2000

tonsoffishisproducedayear,butsincethe

fishfarmislocatedintwosites,itgeneratesa

totalofaround4000tonsperyear.Thisfarmsupplies10.15%ofthetotalHungarianfishproduction.

Fisharestockedatadensityof300kgpercubicmeter.Thecatfishrequirenohealth

treatmentasthespecieshasnoknownviruses,orgeneticdiseases.Gastrointestinalissuescanoccur

occasionallyduetofeeding,butisnotofgreatconcern.Itisaclosedaquaculturesystem,andthe

watercomesstraightinfromthegroundandintoeachtank,thenstraightbackoutagain.Eachtank

isindependentofoneanothersonodisease-bornebacteria/virusescanbetransmittedbetween

tanks,ifadiseaseweretobreakout.

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Fig.3.10Sortingarangeofmarketable-sizedfishintocrates

Fig.3.11Wastesedimentisdrawnoutfromthewater

Fig.3.12Catfishoutdoorenclosure

Fig.3.13Outdoorrearedfish:ControlledFeeding

Thefarmersusecrane-likeequipmenttohaullargevolumes

ofAfricancatfishfromtheenclosure.Fishwhicharewithin

marketable-sizearesortedintocrates(Fig.3.10),readyto

bringtoanotherpartofthefarmforprocessing.Some

buyers/consumerspreferfishthataresmaller,othersprefer

thefishofalargersize.Fishareoftensoldasfilletsreadyfor

cooking.

Waterisfilteredwhenitleavesthetanks(Fig.3.11),andlargeparticlesincludingfooddebris

andalgaeisremovedbeforeitmovesintotheoutdoorenclosureswhereAfricancatfisharefarmed

atalowerdensity(Fig.3.12)andreceivefoodwhichiscontrolledbyatimer(Fig.3.13).Theeffluent

waterrunsthroughaconstructedwetlandsystem,whichpurifiesthewaterbeforeitisledtosurface

waters.

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Fig.3.14162hectaresofpondareaproducing300tonsoffishperyear

3.5.CarpFarm(HortobágyiHalgazdaságZrt)

Thecarpfarm(HortobágyiHalgazdaság)Ivisitedisownedbyaverylargecompanywhich

containsmanysystems.Thefarmconsistsof6units,andthepondareasspan3075hectaresintotal.

Thepondisonly120cmindepthwhichisveryshallow,butitistheaveragedepthforthistypeof

fishfarmedinHungary.Ifthewaterisshallower,thefisharereportedtobelesstastybecausethe

fisharetooclosetothemuddysediment.Thewaterentersthepondsthroughchannelsfromthe

RiverTiszawhichisoneofthebiggestriversinHungary.Thewaterpassesthroughtheponds,then

throughdifferentchannelstootherfishfarms,beforereturningtotheRiverTisza.Theentirecarp

productioncycletakes3yearsfrompropagationtomarketable-sizedfish.Fishareprocessedata

locationnotfarfromthefarm.Fishissoldfreshorfrozendependingontheconsumer’schoice.

Larvaeissourcedfromotherlocationsindependentfromthefishfarm.In162hectaresof

pondarea,300tonsofmarket-sizedfishisproducedperyear(Fig.3.14).Thepondsarefloodedin

theSpringbyrainandoverflowfromchannelsandstreams.Attheendofthefirstseason,fishreach

around50-100g.Attheendofthesecondseasonfishweighinataround400-600g(Summer).Bythe

endofthethirdseason(Autumn),fishhavegainedasignificantamountofweightandarearound

2.5kgandareharvested.Itisnormalattheendofthefirstseasonforthefishfarmerstorecorda

90%loss.Attheendofthesecondseasona50%isoftenseen,butbytheendofthethirdseasonit

plummetstoa10-20%loss.Lossofbiomass/productionisduetothefishnotfeedingfor2-3weeks,

thereforegrainisgiventosupplementtheirnaturaldiet.

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Fig.3.15Grainfeed

Fig.3.16Boatusedtodistributegrain

Fishfeedonnaturallyoccurringorganismslikewormsandlarvae.Additionalfeed(grain)is

providedsothatthefarmerscanmaximiseproduction(Fig.3.15).Theboathasanopeningatthe

bottomwhichallowsthefarmertodistributethefeedinacontrolledmanner(Fig3.16).Around8-10

tonsofmanureisdistributedperhectare-itencouragesfliesandwormstoappearandtherefore

seemstoenhancethepondenvironmentandtheproductionoffish.Noantibioticsareused.The

farmappearstomaintainatotallynaturalsystem.Everythingthatentersthefarmmustbeverified

sothatitcanbeusedinthis‘bioproduction’system.Thepriceof“biofish”andnormal/non-biofishis

thesame,butintimethehopeisthatHungarianconsumerswillfavournaturallyfarmedfish

bioproducedfish,overothermoreintensivemethodsoffarmingfish.

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Fig.3.18Oxbow.Watercompositionstudysite

Fig.3.17Outdoorcarpfeedingexperiment

3.6.ResearchexperimentsatHAKI

SeveralexperimentswerebeingundertakenduringmyvisittoHAKIwithstudysitescloseby

totheinstitutes.Groupsofcarpwerecloselyfedandwatchedovertime-aresearcherusesaboat

tomovetoeachenclosuresothatthefishcanbefedandsurvivalandconditionindexcanbe

monitored(Fig.3.17).Awatercompositionstudywasalsobeingundertakenatanoxbownearto

HAKI(Fig.3.18).Theoxbowtakestheeffluentwaterfromthecatfishfarmtosurfacewaters.The

studywastomonitorthewaterquality,andIwasabletoassisttheresearchersinaboattocollect

dataforthisstudy.

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Fig.4.1Norway,showingthelocationoftheresearchstation(lowercircle)andsalmonfarm(uppercircle)Source:Welt-atlas

4.TRIPTONORWAY4.1AquacultureinNorway

AquacultureinNorwayspecialisesinmarinefishsinceitissurroundedbytheNorthSeaand

theAtlanticocean(Fig.4.1).FarmingofAtlanticsalmonisthemostimportantactivity,andaccounts

formorethan80%ofthetotalNorwegianaquacultureproduction(FAO,2017).Salmonare

anadromousspecies,havingafreshwaterandsaltwaterphaseintheirlifecycle.Salmonhatchas

alevins,developintoparr(duringwhichvertical‘parr’markingsarevisible).Theythenenterthe

smoltstage(salmondevelopasilveryappearanceandphysiologicaladaptationtothemarine

environment).Theselifephasesoccurinonshorefreshwatertanks.On-growingtomarketsizetakes

placeinoffshoremarinecages/openseacages.

4.2NOFIMA

NOFIMAhasseveralresearchstations.IwasbasedataresearchstationatSunndalsøra

wheretheNOFIMACentreforRecirculatingAquacultureSystemislocated.Researchareas

investigatedatNOFIMAincludebreedingandgenetics,fishheath,foodsafetyandquality,and

seafoodprocessing.Therearealsox-rayfacilitiestoviewabnormalitiesintheformationofthe

spineinfish.Fishdeformitiescanbecausedbyexposuretotoomuchphosphorusandhighwater

temperatures.

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Fig.4.4Salmonhatcherytankwithownwatersupply

Fig.4.3Salmonhatcherytankswithpipes

Fig.4.2Salmonhatcherytankwithartificialgravel

4.3SalmonHatcheryThesalmonhatcherytankconsistsof

twoparts:agreen,structured,

removablelayerthatmimicsgravel,

andaperforatedtraywhichsitsatop

thegravelandoffersbothshelter

andameansforwaterflowcreating

ariffleeffectasyouwouldfindin

naturalriversystems(Fig.4.2).

Salmoneggsaredistributedinthe

gravellayerandthentheperforated

trayispositionedontop.Finallyeachindividualtankiscoveredwithalidtoofferprotectionfrom

lightandtheopenair,thuslimitingspreadofdisease.

Eachhatcherytankisprovidedwith

itsownwatersourceviathelarge

piperunningalongtherowoftanks

(Fig.4.3).Oncethewaterpasses

throughthelayers(mentioned

above),itpassesthroughapipeat

thebottomofthetankandbackout

intotheriver.

Inthiswaywaterdoesnotpassfrom

onetanktoanother,thustheeggsin

eachtankarenotexposedtoany

diseases,norodourcuesfromany

othertanks(Fig.4.4).Thissystemis

usedtoinvestigatetheeffectof

waterqualityanddiseaseresistance

ontheeggsfromdifferentfamily

groups,hencetheinteraction

betweengeneticsandthe

environmentcanbeexamined,andkinshipstudiesarealsopossiblewiththisexperimental

structure.

21

Fig.4.5SalmonfeedingtrialsI

Fig.4.6SalmonfeedingtrialsII

4.4Juvenilesalmonfoodtrails

Inthetanksusedforfeedingtrials,waterentersthroughthetoplargepiperunningalong

aboveallthesmallindividualenclosures(Fig.4.5).Eachenclosurereceiveswaterfromthelargepipe

byopeningthesmallredtaptofillthetanktothedesiredwaterlevel.Thewaterafterpassing

througheachenclosure,passesthroughapipewhichextendsfromtheenclosureintotheground.In

thisway,waterdoesnotpassbetweenenclosures,thusstudiesonkinship,andwatercontamination

arepossible.

Juvenilesalmonparr,familygroupswereheldinseparatetanksandwereprovidedwith

foodwhichdifferedfromtanktotank(Fig.4.6).Thistypeofinvestigationenablesfood

manufacturerstotestwhichfoodismorefavourabletojuvenilesalmon.Thedeliveryofameasured

volumeoffoodiscontrolledbyautomatedequipmentwhichcanbesetbyatimer.Foodmight

differintheamountofnutrients,protein,colour,sizeandshape.

22

Fig.4.7Kinshipstudies

Fig.4.8Processingunit

Researchersmanipulatedjuvenilesalmonparrintosibling

groupswithisolatedsiblinggroupsfedadifferenttypeof

foodandthengrowthratemeasuredovertime(Fig.4.7).

Thisusefulinformationprovidesfishfarmerswithan

understandingofgrowthrate,andfoodpreference

dependingonthesuitabilityofthetypeoffoodfor

particularlyfamilystrains.

4.5ProcessingFish

Aprocessingroomcontainsthe

equipmentneededtomeasureand

identifyfish(Fig.4.8).Inthisroom

thereisaweighingscaleand

measuringplatformtorecordgrowth

rateoffish.Thereisalsoahand-held

toolwhichallowstheuserto

accuratelyinsertaPassiveIntegrated

Transponder(PIT)tagintothefish

moreaccuratelythanusingtraditionalmethods(whichpreviouslyinvolvedmakinganincisioninthe

fishandinsertingthePITtagbyhand).Thisaccuratetechniquepromotesahigherwelfareforthe

fishaswellasloweringmortality.PITtagsaresmallcapsulescontainingabarcodetohelpidentify

individualfish.APITtagreaderisalsoconnectedtotheweighingscalessothatfishmaybe

identifiedwhilebeingsimultaneouslyweighed.Thisallowsthescientiststocollectdifferentdataat

thesametimeandreducestheamountoftimethefishishandled.

23

Fig.4.9Re-circulatingAquacultureSystem(RAS),NOFIMANorway

Fig.4.10Re-circulatingtanks

4.5RecirculatingAquacultureSystemExperimentsarecarriedoutonAtlanticsalmoninRecirculatingAquacultureSystems(RAS)

tounderstandtheoptimalconditionsrequiredtomaximisegrowthrateandobtaingoodquality

marketablesalmon.RASforAtlanticsalmonfarmingisarelativelynewareasincethesalmons’life

historyiscomplex,andtheirenvironmentalrequirementsareveryspecific.Researchisstillneeded

tounderstandhowtoincreasebiomassandlowertheincidenceofmortality,whileconsideringthe

welfareofthefish.IwasimpressedwiththesizeoftheRASatNOFIMA(Fig.4.9)andmostlyhow

efficientlytheresearchersweremonitoringthefishandmaintainingtheentiresystem.

Thetanksoftherecirculatingsystem(Fig.4.10)are

muchlargeranddeeperincomparisontothetanks

usedintheRASinHungaryforcatfish(comparewith

Fig.3.3).ThestockingdensityofAtlanticsalmonis

muchlower,andtheyrequiremuchdeeperwaters,

whereascatfishcansurviveinveryshallowwater

andevendroughts.Thesizeofthetanks,andsheer

volumeofwater,nottomentionthetemperature

sensitivityanddiseasesusceptibilityofAtlanticsalmon,areattributesthatdriveupthecostof

farmingAtlanticsalmon.

24

Fig.4.11HighspeedboattoHitra

Fig.4.12Indoorsalmonhatcheryfarm

4.6Salmonfishfarm(LerøyBelsvik)

Ahigh-speedboatwasusedtotravelto

LerøyBelsvik(Fig.4.11)tovisitoneofthe

biggestfishfarmsintheworld.Thiswas

myfirsttimeonaboatgoingatsucha

highspeedsoIwasbothexcitedand

nervousaboutthewholeexperience!The

sitehaslargelivingquartersforon-site

staffwhoattendtotheoutdoorfish

areas.

Thesheersizeofthefishfarmisquite

breath-taking.Therearesomanyareas

forfishofdifferentlifestagesandsizes

andjustwhenyouthinkyou’veseenit

all,youwalkdownacorridortofind

anotherhugepartofthefishfarm.Most

ofthefishfarmwasinanenclosed

environmentandcouldonlybeviewed

fromplatformsbehindwindows(Fig.

4.12).Iassumemuchofthiswastolimit

diseasespread.Whatwassoincredible

wasthewayinwhichthefarmwassetup.Awholeenclosedareawouldbededicatedtosalmonat

thejuvenilestages.Juvenileswouldbesortedinorderoftheirsize.SoIobservedmanydifferent

tanksdedicatedforsalmonofaspecificsizerange.Asmentionedbefore,thesalmonlifehistoryisso

complex.Sinceitspendsitsjuvenilestagesinfreshwater,theindoortankenvironmentisvery

suitable,howeversalmondogothrougha‘smoltification’stageduringwhichtheyundergo

physiologicalchangesaspreparationforlifeinthemarineenvironmentasadults.Thesmoltification

processisoftenmediatedbylengthofdayandagradualadaptationtosaltwater.Therefore,there

arealsodedicatedareaswithintheindoorpartofthefishfarmthataresolelyforrearingsalmon

‘smolts’,andlightisregulatedduringthisstagesothattheymaybefullypreparedforthemarine

environmentoutdoorseacages(Iwilltalkaboutthislater).

25

Fig.4.13biofiltertank,Hitra

Fig.4.14Biofiltercloseup,Hitra

MymostinterestingfindatHitrawerethebiofiltersthatareusedtocleantherecirculating

water(Fig.4.13).ThebiofiltersusedinNorwaywereofadifferentshapeandsizethebiofiltersI

observedinHungary(comparewithFig.3.6),althoughIlearntthatthesurfaceareaiswhatisof

mostimportance–sothatalargeramountofspaceisavailabletosupportandlargervolumeof

bacteriathatconvertammoniatoless-toxicnitrate(Fig.4.14).

.

ThebiofilterisakeycomponentofthefiltrationprocessoftheRAS.Fishexcreteammonia

(NH3),whichistoxictothefishandisanenvironmentalstressor–thereforeitcanreduceappetite

andgrowthrate,andincreasemortalityrates.Naturallyoccurringbacteriaoxidizetheammoniaand

convertittoNitritewhichisalsotoxictofish,thereforefurtheroxidizationisnecessarytoremove

thetoxicformofnitrogen.BacteriafromthePseudomonasspp.iscultivatedonthesurfaceareaof

thebiofilters.Thebiofiltersaredesignedtobecompactunitswithasmuchsurfaceareaaspossible

sothattheycanholdlargevolumesofpseudomonasspp.Thesebacteriametabolizeandoxidizethe

nitrite,andconvertittonitrate(NO3),thusmaintainingacleanandviableenvironmentforthe

farmedfish.

26

Fig.4.15Outdoorseacage

TheopenseacageatLerøyBelsvikconsistsofarigidcircularstructurewhichsitsonthe

surfaceoftheocean(Fig.4.15).Thisrigidstructureholdsameshcagewhichissubmergedinthe

ocean,andcontainsthefish.UnlikeaRecirculatingAquacultureSystem(RAS),thefishintheopen

seacagearecompletelyexposedtotheoceanwaterflowinginandoutofthecage,andthiscreates

anaturalenvironmentforthefish.Thisrendersthefishathighriskofcontractinginfectionseither

viral,orparasitic(discussedlater).Fishfarmerscanexperiencehugelossesoffishduetodisease,

andthisisoneofthemajorproblemsofsalmonaquacultureinthemarineenvironment.

Underwatertechnologyisbeingcreatedinordertodetectsealiceinfestationsasearlyaspossibleso

thatparasiteloadcanbedeterminedandbecontrolledmoreefficiently.

Thefisharefed,andvaccinesareadministeredintothecage,sowasteproductsand

uneatenfeedfallsthroughthebottomofthecageontothebottomoftheocean.Thisisclearlyan

environmentalconcern,sooutdoorrecirculatingsystemsarebeingconsideredforthefutureof

marinesalmonfishfarming,butwearestillattheearlystagesofexperimentation.

27

Fig.4.16SeaLice

Fig.4.17SeaLicewarmwatertreatment

WhileIwasatLerøyBelsvik,Ihadthe

pleasureofattendingalectureaboutthe

evolutionoffishfarmingtechniquesand

technology.Whatinterestedmethemost

wastheprevalenceofdiseaseandits

management.Sealice(Caligusspp.)isone

ofthemajorectoparasitesthatfishfarmers

aremostconcernedabout,particularlyin

openseacageswherefisharecompletelyexposedtowaterfromtheoceanenteringandleavingthe

cageconstantly.

Thefemalesaresignificantlylargerthanthemales(seetopparasiteinFig.4.16)The

parasitesattachthemselvestosalmon(thehost),andthefeedingoftheparasitescauseschangesin

mucusconsistencyanddamagetotheepitheliumofthefish,whichcanresultinbloodloss.Thesea

licedetachfromsalmonwhentheyenterthefreshwaterenvironment(whentheymigratetotheir

natalstream).Theyarealsointolerantofwarmerwatertemperatures,sofishfarmersuseasystem

tomovesalmonfromopencagesthroughapipefilledwithwarmerwaterwherethesalmonare

deloused,beforereturningtotheseacage(Fig.4.17)

28

5.POTENTIALAQUACULTURECOURSEDESIGN

5.1VisittoSparsholtCollege

IvisitedSparsholtCollegetomeetAdrianLove,aformerrecipientoftheFarmersClub

Educationaward,andcoursemanageroftheaquaculturecourseatSparsholt.Adrianwasableto

talktomeaboutthecoursecontent,assessmentsandoffsiteplacementsundertakenwithindustries

thatthecollegehaslinkswith.Iwasalsoabletolookaroundthecollegefacilitiesandwasvery

impressedwiththeAquaticResearchandConservationCentrewhichhousescatfish,carpandtilapia

aswellasornamentalvarieties.IwasalsoabletoviewtheSalmonidRearingandTrialCentrewhere

fishfeedtrialsareundertakenandstudentscanconductavarietyofexperimentsfortheir

dissertation.Sparsholtalsohasitsownnaturalpondlocatedjustoutsidethelabsandindoor

aquaria.Itreallyisfascinatinghowwellequippedtheyareforrunningsuchacourseandstudents

areluckytohavethesefacilitiesontheirdoorstep!

DuringthistriptoSparsholt,IrealisedthevastamountofspaceandexpertisethatIwould

needtoconsiderpriortopotentiallycreatinganaquaculturecourseatWrittle.Itwouldtaketimeto

developlinkswithindustries,acquirespaceandfundingforaquaculturetechnology,andacquire

experiencedlecturerswithsoundknowledgeoffishfarmingandtechniques.Nonetheless,itisa

coursethatIfeelcouldpotentiallyattractmanyinterestedstudentssinceaquacultureisafast

expandingindustryworldwide.

5.2AquaculturelecturesatWrittle

OnmyreturntoWrittle,Iwasabletodesignasuiteofaquaculturelecturesincorporatinga

lotofwhatIlearnedduringmytripstoHungaryandNorway.Thelectureswerereceivedbystudents

verywellandIfoundmoststudentsintheyearoptedtoanswermyaquacultureessayquestionsand

examquestions.TheywouldoftenquotethetechniquesusedatHAKIandNOFIMA.Belowarea

sampleofPowerPointslidesfromoneofmylectures.

29

5.3Aquaculturelecturesamples

30

31

6.CONCLUSION

TheFarmersClubEducatorsAwardenabledmetotraveltoHAKIinHungaryandNOFIMAin

Norwaytospeaktotheexpertsinthefieldofaquaculturelearnaboutnewresearchandtechnology

emerginginthefield.ThegrantenabledmetovisitacatfishandcarpfarminHungary,andasalmon

farminNorway,thereforeIwasabletoobservethedifferencebetweenfishfarminginthe

freshwaterandmarineenvironmentintwodifferentcountries.Thegrantalsoallowedmetovisit

SparsholtCollegewhereanAquaculturecourseisbeingrun,thusIhavebeenabletolookatthe

facilitiesandcoursecontent,andexplorethepotentialdevelopmentofanaquaculturecourseat

WrittleUniversityCollege.

Withregardstomythreeprojectobjectives,Ihavefulfilledthefirsttwo.However,thethird

objective;myideatodesignanewAquaculturecourseatWrittle,wouldbesomethingthatwould

requireahugeamountofthoughtandfundingtosetup(seepg.28formoreofmythoughtsabout

this).Thisismoreofalong-termgoal.None-the-less,asshort-termgoalIhavebeenandwill

continuetoeducatemystudentsandthestaffatWrittleonthetopicofaquaculture.Therefore,I

havepartiallyfulfilledobjectivethree,byintroducingaquaculturetoavarietyofmodulesonthe

AnimalScienceandAnimalManagementdegreeprogrammes(seepg.28-30forsamplesoflecture

slides).Iwasalsoabletodeliveralectureaboutmytriptostaffinmydepartment,andthiswas

receivedverywell,withenthusiasmandnumerousquestionsfollowingmytalk.Ihopetoinstilthe

passionforfishfarminginthelecturersIworkwithsothatevenonmodulesthatIdonotteach,they

willcontinuetoteachaquacultureaspartoftheirownmodulespecifications.Afterall,aseducators

ofanimalscienceandmanagementprogrammesitisinourhandstoenlightenpeopleaboutthe

fascinatingandalternativemethodsofproducingfishworldwideforourgrowingpopulation,andwe

needtodeveloppeople’sknowledgeandenthusiasmtobecomeexpertstosupportthefast

expandingindustryofaquaculture.

32

REFERENCESAgriFarminghttp://www.agrifarming.in/catfish-farming-information/(accessed12/07/17)Atlanticcanadaexportshttp://atlanticcanadaexports.ca/wp-content/uploads/2011/05/atlantic-salmon-01-thumb.jpg(accessed12/07/17)Bruton,N.M.(1979).TheBreedingBiologyandearlyDevelopmentofClariasgariepinus(pisces.Clariidae)inLakeSibaya,SouthAfrica,withreviewofbreedinginspeciesofsubgenusClarias.TransactionsoftheZoologicalSocietyofLondon35,1-45.DadaA.A.andWonah,C.(2003).ProductionofexoticC.gariepinusatvaryingstockingdensityinoutdoorponds.JournalofAquaticScience18(1),21-24.DepartmentofPrimaryIndustrieshttp://www.dpi.nsw.gov.au/__data/assets/image/0004/636790/Common-carp-Pat-Tully.jpg(accessed12/07/17)Edwards,A.,Ladu,B.M.B.andElihu,A.(2010)Growth,survivalandproductioneconomicsofClariasgariepinusfingerlingsatdifferentstockingdensitiesinconcretetanks.AfricanJournalofGeneralAgriculture.Vol.6(2),59-66.EuropeanCommission(2017)https://ec.europa.eu/fisheries/home_en(accessed12/07/17)FAO.2013.Fishstateplus:Universalsoftwareforfisherystatisticaltimeseries(availableat:www.fao.org/fi/statist/fisoft/fishplus.aspFAO(2017)http://www.fao.org/(accessed12/07/17)FAOFactsheet1http://www.fao.org/fishery/species/2982/en(accessed12/07/17)FAOFactsheet2http://www.fao.org/fishery/culturedspecies/Cyprinus_carpio/en(accessed12/07/17)Flickrhttp://farm5.static.flickr.com/4116/4735703857_dc30c22f99_o.jpg(accessed12/07/17)Freyhof,J.&Kottelat,M.2008.Cyprinuscarpio.TheIUCNRedListofThreatenedSpecies2008.http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T6181A12559362.en(accessed12/07/17)Froese,R.&Pauly,D.(eds.).2011.FishBase.WorldWideWebelectronicpublication,version(02/2011)www.fishbase.org/summary/speciessummary.php(accessed12/07/17)GlobalSalmonInitiativehttps://globalsalmoninitiative.org(accessed12/07/17)IUCN(2017)http://www.iucnredlist.org(accessed12/07/17)Life.In.A.Tankhttp://lifeinatank.blogspot.co.uk(accessed12/07/17)MarineHarvesthttp://marineharvest.com(accessed12/07/12)

33

SeaMaxGlobalhttp://seamaxglobal.com/wp-content/uploads/2016/02/atlantic-salmon.jpg(accessed12/07/17)TEShttps://www.tes.com/lessons/e7ds6Uf2DUumrg/hungary(accessed12/07/17)Verspoor,E.(2007)Introduction,inTheAtlanticSalmon:Genetics,ConservationandManagement(edsE.Verspoor,L.StradmeyerandJ.Nielsen),BlackwellPublishingLtd,Oxford,UK.Webb,J.,Verspoor,E.,Aubin-Horth,N.,Romakkaniemi,A.andAmiro,P.(2007)TheAtlanticsalmon.inTheAtlanticsalmon:Genetics,ConservationandManagement(edsE.Verspoor,L.StradmeyerandJ.Nielsen),BlackwellPublishingLtd,Oxford,UK.Welt-atlashttps://www.welt-atlas.de/map_of_south_norway_1-862(accessed12/07/17)