Fish Farm Fcf-recirculation

7/28/2019 Fish Farm Fcf-recirculation

1/51

Cefas contract report

FES220: A review of the land-based, warm-water recirculationfish farm sector in England andWales.

Authors: Keith Jeffery, Nicholas Stinton & Tim Ellis

Cefas Weymouth Lab, Barrack Road, The Nothe, Weymouth,Dorset, DT4 8UB


2/51

1 Executive summary

ThewarmwaterRecirculationAquacultureSystem(RAS)sectorhasshownconsiderablegrowth

withinEnglandandWalesoverthelastdecade.Environmental,politicalandsocialfactorswithin

Englandarecombiningtoprovideconditionsfavourabletofuturedevelopmentofthesectorwhich

ticksmanyboxesforenvironmentalandsocialsustainability.RASrepresentahighlyproductive

meansofgrowinganimalproteinonsmallareasofland.Ifenergy(fossilfuel)useandtheassociated

carbonfootprintcanbereduced,RASsystemswouldappeartomeettherequirementfor

sustainableintensification,recognisedasakeymeansofaddressingfoodsecurity1

.

Nevertheless,itmustberecognisedthatfinancialviabilityofRAShassofarbeenmarginal.RAS

businesseshaveapoorrecordforlongevity,andanumberofventureshavefailed.Thisproject

identifiedpoorsystemdesign,lackofattentiontoeconomicfactors(e.g.electricitycosts),andlow

demandforproducts(resultinginlowpriceandsalesvolume)asthecausesoffailure.However,this

pessimisticviewoftheUKexperiencemaybeskewedasthesectorhasbeennumericallydominated

byfreshwatertilapiasystemswheresystemdesignissueswerecommon; veryfewseawater

systemsproducinghighervalueproductsareoperatingtojudgetheviabilityofmarineRAS.

Newentrantsneedtoproceedwithcautionandoptimisesystemdesign,economiesofscale,input

costs,andmarketingandsalesplans.Inaddition,experiencedstaff,systemflexibilityandfurther

developmentofsurroundingindustry(i.e.frysupplyandtechnologicalprogress)remaincriticalifthe

RASsectoristogrow.Issuesthatremaincanbeaddressedthroughacombinationofresearchand

developmentandadoptionofaccreditationandqualitylabellingschemes.

Grantawarders(andinvestors)shouldensurethatapplicantshaveresearchedsystemsadequately,

havefirsthandexperience,andthatbackupsystemsareinplace.Applicantsalsoneedtominimise

inputcostsandproducerealisticbusinessplansthataddressmarkets.Pilotstudiesshouldbe

encouraged.Projectsshouldnotbedismissedthatareinnovativeortransfertechnologyfromother

industriestosupportsustainability.

1

GodfrayHCJ,BeddingtonJR,CruteIR,HaddadL,LawrenceD,MuirJF,PrettyJ,RobinsonS,ThomasSM,ToulminC(2010)Foodsecurity:thechallengeoffeeding9billionpeople.Science327:812818


3/51

Table of contents

1 Executive summary ...................................................................................................................... 12 Introduction ................................................................................................................................... 2

2.1

Disclaimer

..............................................................................................................................................

4

3 Methodology .................................................................................................................................. 54 Status and prospects of the warm-water RAS industry in England and Wales. .................... 7

4.1 NumbersofRASsitesinEnglandandWales......................................................................................... 7

4.2 ProductionoftablefishinRASinEnglandandWales.......................................................................... 8

4.3 RAScontributiontotablefishproduction............................................................................................ 9

4.4 TheRASindustryinEurope................................................................................................................... 9

4.5 ProspectsfortheRASsectorinEnglandandWales........................................................................... 11

4.6 ProspectsforRASuseintheScottishsalmonsector.......................................................................... 11

5 Technology, performance and operat ion of RAS .................................................................... 125.1 ThefundamentalsofRAS.................................................................................................................... 12

5.2 Mechanicalfiltration........................................................................................................................... 14

5.3 Biologicalfiltration.............................................................................................................................. 15

5.4 Aeration/oxygenation ......................................................................................................................... 16

5.5 Heating................................................................................................................................................ 17

5.6 Sterilisationofinlet/returnwater....................................................................................................... 17

5.7 Pumping.............................................................................................................................................. 18

5.8 Tanks................................................................................................................................................... 18

5.9 Pipework............................................................................................................................................ 18

5.10 Monitoringsystems............................................................................................................................. 19

5.11 Automaticfeedingsystems................................................................................................................. 19

5.12 Watersources,replacementanddischarge....................................................................................... 19

5.13 Lessonstobelearnt............................................................................................................................ 20

5.14 NextgenerationRAS........................................................................................................................... 22

6 Financial sustainabi li ty of RAS ................................................................................................. 24

6.1 Fundingsources.................................................................................................................................. 246.2 Buildandsetupcosts......................................................................................................................... 24

6.3 Runningcosts...................................................................................................................................... 24

6.4 Planned vactualsalesprice............................................................................................................... 27

6.5 Productioncosts,paybackandaccountingrateofreturn.................................................................. 27

6.6 Literaturereviewfindings................................................................................................................... 28

6.7 Overallassessmentoffinancialsustainability..................................................................................... 29

7 Factors leading to his tor ical failure of some RAS ................................................................... 307.1 Top10criticalfactors...................................................................................................................... 30

7.2 Additionalfactorscontributingtofailure............................................................................................ 31

7.3 Markets............................................................................................................................................... 31

7.4 Addingvalue:processing,accreditationschemesandbranding........................................................32

7.5 Economiesofscale.............................................................................................................................. 338 Sustainabi li ty issues relating to RAS ....................................................................................... 34

8.1 Environmentalprotection................................................................................................................... 34

8.2 Naturalresourceuse........................................................................................................................... 36

8.3 Socialissues......................................................................................................................................... 39

8.4 Employment........................................................................................................................................ 42

9 Strengths, weaknesses, oppor tuni ties and threats to the RAS sector. ................................ 439.1 PEST Analysis...................................................................................................................................... 43

9.2 SWOTAnalysis..................................................................................................................................... 44

9.3 IdentificationofR&Drequirements.................................................................................................... 45

10 Conclusions ............................................................................................................................. 4610.1 Acknowledgements ............................................................................................................................. 47

11 Annex 1: Line graphs i llustrating operating periods of indiv idual farms ......................... 48

WarmwaterrecirculationfishfarmsinEnglandandWales Page1of48


4/51

2 Introduction

MostoftheexistingUKfinfishaquacultureindustryisbaseduponopen,flowthroughsystems

where

natural

water

bodies

provide

a

clean

water

supply,

and

remove

and

assimilate

wastes.

Such

culturesystemshavebeencriticisedastheyaredependentuponthissubsidyfromnatureand,if

intensive,canincuranenvironmentalcostonthesupplying/receivingenvironment2

.Analternative

modelforintensivefinfishproductionisclosedRecirculationAquacultureSystems(RAS).InRAS,

waterisrecirculatedandtechnologyisusedtoremovewastesandmaintainoxygenlevels.RASare

oftenperceivedashavingstronggreencredentials3 andRASproductsarepromotedassustainable

byenvironmentalorganisationssuchasSeafoodWatch4andGreenpeacebecause,asclosed

systems,they

abstractlittle,ifany,waterfromnaturalwaterbodies

produceminimaleffluent,withreadilymanagedwastestreams

reducethepotentialenvironmentalimpactsfromescapeeandpathogenrelease

RASalsooffermanypotentialbenefitstotheproducerandsupplychain:

controlofthefishesenvironmentallowsconsistentandpredictableproduction,essentialfor

modernfoodproduction;

removalofdependenceonanatural,clean,flowingwatersupplyeliminatesseasonalvagaries

(e.g.floods,droughts)associatedwithnaturalwatersupplies,widenspotentiallocations,and

enableslocationclosertomarkets;

improvedbiosecurityinclosedsystemsreducestheriskofpathogeningressanddisease

outbreaks;

closedsystemseliminatelossesto,andconflictswith,predators;

containmentwithinbuildingsaidstemperaturecontrol,therebyavoidingseasonalityin

production;

heatingallowsalternativetropicalfastgrowingspeciessuchasNiletilapia(Oreochromisniloticus)tobefarmed.

2PelletierN,TyedmersP(2008).Lifecycleconsiderationsforimprovingsustainabilityassessmentsinseafoodawarenesscampaigns.

EnvironManage42,918931.3LittleDC,MurrayFJ,AzimE,LeschenW,BoydK,WattersonA,YoungJA(2008).OptionsforproducingawarmwaterfishintheUK:limits

togreengrowth.TrendsinfoodScience&Technology19,255264.4Pelletier&Tyedmers(2008).op.cit.



5/51

Despitetheseapparentbenefits,RASmayattractcriticismonenvironmentalgroundsduetohigh

energyusageanditsassociatedenvironmentalimpacts(carbonandacidificationemissions)5 and

forethicalreasonsRASaretypicallyintensivesystems,whichmaybeviewedasfactoryfarms.

Overthelast10yearstherehasbeenanotableincreaseinboththenumberandsizeoflandbased,

warmwaterRASfarmsinEnglandandWales. In2000therewas acoupleofsmallscalefarms,buta

decadelaterthisisapproaching20farmswhichvaryinscalefrom10to1000tonnesp.a..These

newfarmsrepresentadiversificationintheUKaquacultureindustry,andprovideanadditional

routetoproduceahealthyfoodproduct,therebystrengtheningUKseafoodsecurity.However,

despitetheoptimismsurroundingRAS,anotableproportionhasgoneintoadministration6

7.

Variouspotentialfactorshavebeensuggestedanecdotallyascontributingtotherecurrentfailureof

commercialRASintheUK89:

poordesign

toohighrunningcosts

labourintensivetechnology

steeptechnicallearningcurves

lackofexperiencedstaff

overambitiousproductionschedules

overoptimisticmarketforecastsforproductsales

poormanagementdecisions

Todate,therehasnotbeenanobjectiveexaminationofthefactorsthatcontributetothefailure

(andsuccess)ofcommercialRASintheUK.ThisprojectwasfundedbytheDefraFisheriesChallenge

Fund,administeredbytheMarineManagementOrganisation(MMO,formerlyMarineFisheries

Agency)toaddressthisgap,andreviewthetechnology,operation,production,problemsand

sustainabilityofwarmwaterrecirculationaquaculturesystemsinEnglandandWales.Thisreportis

intendedtoprovideasourceofUKspecificinformationonRASforprospectivefarmers,investors,

policymakersandlobbygroupstoaiddecisionmaking.

5SeeEllisetal.(2011)InitialinvestigationofthesustainabilityofEnglishaquaculture.CefascontractC3743reporttoDefra.

6LittleDC,MurrayFJ,AzimE,LeschenW,BoydK,WattersonA,YoungJA(2008).OptionsforproducingawarmwaterfishintheUK:limits

togreengrowth.TrendsinFoodScience&Technology19,255264.7E.g.http://www.fishupdate.com/news/fullstory.php/aid/10782/Barramundi_farm_brings_in_administrators.html8http://www.slideshare.net/Cefas/largescaleintensiverecirculationsystemsandtheirpotentialdevelopmentwithinengland2373881

9Littleetal.(2008)op.cit.



6/51

2.1 DisclaimerWhilsteveryefforthasbeenmadetopresentanaccuratesummaryofinformation,Cefasandthe

authorscannotbeheldresponsibleforinaccuraciesoromissions.ReadersinterestedinRASare

encouragedtoconducttheirowninvestigationsand/orseekspecialistadvice.



7/51

3 Methodology

Theprojectwascomposedoffoursuccessivestages:

a

desk

based

literature

review;

identificationofallwarmwaterRASfarmsinEnglandandWalesregistered(andderegistered)

between2000and2010,andcollationofproductiontoassessthecontributiontothefinfish

supplychain.[TheCefasFishHealthInspectorates(FHI)LiveFishMovementDatabase(LFMD)

wasusedtoidentifyallregistered(andderegistered)warmwaterRASfarmsinEnglandand

Walesandrelevantdatawasextracted];

asurveyofrepresentativesofthewarmwaterRASindustry, i.e.farmersandconsultants,to

gatherinformationontechnology,operation,production,problemsandsustainability.

collationoftheinformationintothisreport,andreviewbyrepresentativesoftheindustry.

TheaimofthesurveywastocoveralargeproportionoftheRASsitesinEnglandandWalesand

includebothoperatingandnonoperating(inreceivershiporceasedtrading)sites,togatherdiverse

feedbackontheissuesfacedbythissector.Theapproachtothesamplingmethodologywas

discussedwithaCefasstatisticianandrecommendationsincorporated.

Ofthe29farmsidentifiedonthedatabase,asampleoffarmswasselectedforpreliminary

discussion(n=18)andthesewerecontactedbytelephonetorequestagreementtoparticipate.Two

farmswereunwillingtoparticipateinthesurvey. Ascheduleoffieldvisitswasthenarranged.

Duringschedulingtwofurtherfarmerswithdrewfromthesurvey,astheywereunavailableinthe

allottedtimeframeorwerenolongerabletoproviderequiredinformation. Itwasjudgedthatthe

remaining14farmswereadequateforthereview.Productionfiguresandotherrelevantdatawere

gatheredduringtheinitialtelephoneconversationsforthenonparticipantsandareincluded(with

permission).

ThefieldvisitswereconductedoveratwoweekperiodinlateAutumn2010.Fourteensites

producingavarietyofspecies,locatedthroughoutEnglandandWales(e.g.Devon,Cambridgeshire,

York,DurhamandAnglesey)werevisited(Table1).Theschedulewasarrangedtominimise

travellingwherepossible,andvisitswerecombinedwiththeroutineannualFHIinspectionwhere

applicable.



8/51

SitevisitswereconductedbytwoCefasprojectstaff(theprojectleaderandanexperiencedRAS

operator),andcomprisedaninspectionofthesiteandrecirculationsystemandasemistructured

interviewwiththefarmmanger. Theinterviewwasstructuredaroundaquestionnaireproviding

promptsforthemainissuesidentifiedfrompersonalknowledgeandtheliteraturereview.The

presenceoftwoprojectstafffacilitatedcaptureofinformation. Farmerswereadditionallyaskedto

identifyandranktheirTop10criticalfactorsforthesuccessorfailureofawarmwater

recirculationfishfarmfromalistof34putativefactorsidentifiedfromtheliteratereviewand

personalknowledge.Spacewasprovidedtoaddadditionalfactorsandcomments. Production

figureswerecollecteduptoandincluding2010;forsitesthathadceasedoperating,finalproduction

wasrecorded.

RASconsultantswerepresentattwoofthefarmsites,andtheirinputwasgatheredfollowingthe

samesemistructuredinterviewformat.

Table1:BreakdownofRASoperatorsinterviewed,byspeciesfarmedandoperationalstatus.

Typeoffarm Operational Closure

Imminent

Non

operational

Total

Tilapia 3 2 1 6

Tilapia&catfish 1 1 1 3

Turbot 1 1

Turbot,sole,prawn&seabass 1 1

Seabass&turbot 1 1

Barramundi 1 1

Prawn 1 1

Totals 7 4 3 14



9/51

4 Status and prospects of the warm-waterRAS industry in England and Wales.

Detailsofallwarmwaterrecirculationfishfarms(thoseproducingfoodfish)registeredinEngland

andWalesbetween2000and2010wereextractedfromtheLFMDandsupplementedwithsite

specificdata.DataforWaleswasincludedalongsidethatforEnglandduetothecoverageofthe

database,andthenatureandimportanceoftheseoperations.

4.1 NumbersofRASsitesinEnglandandWalesWithinEnglandandWales,29warmwaterRASsiteswereregisteredduringtheperiod20002010

(Table2).Thesehavetargetedavarietyofspecies,withaclearinclinationtowardstilapia.Ofthese

29sites,only18arestilloperationaland11haveceasedoperating.

Table2: Numbersofwarmwaterrecirculationfishfarmsitesregisteredbetween2000and2010,

andcategorisedaseitheroperationalin2010ornonoperational.NB:Datacontainsonehatchery

thatmovedlocation.

Speciesheld Numbersites

registeredbetween

2000and2010

Sites

operationalin

2010

Sitesnot

operatingin

2010

England

Tilapia

18

9

9

Tilapia&catfish 3 3 0

Barramundi 1 0 1

Hybridstripedbass 1 0 1

Prawns 1 1 0

Turbot 1 1 0

Grasscarp 1 1 0

Subtotal 26 15 11

Wales Sole,bass,prawns&turbot 1 1 0

Turbot&bass 1 1 0

Bass 1 1 0

Subtotal 3

3

0

Total 29 18 11

ThewarmwaterRASindustryinEnglandandWaleshasshownconsiderabledevelopmentoverthe

lastdecade,witha10foldincreaseinthenumberofoperatingfarms(Fig1A).However,thismarked

increasedoeshidethefactthataround40%offarmshaveceasedoperating(Fig1B).



10/51

5

0

5

2000 2002 2004 2006 2008 2010

B

0

5

10

15

20

2000 2002 2004 2006 2008 2010

NumerofoperatingR

ASfarmsinE&W

A

Newinyear

Ceasedinyear

Figure1:

A:

Number

of

warm

water

RAS

farms

operating

in

England

and

Wales

in

the

years

2000

2010.B:Foreachyear,thenumberofnewRASfarmsregistered,andthenumberthatceased

operating.

Simplelinegraphsareincluded(Annex1)toillustratesitenumbersbyspeciesfarmed,andthe

periodofproductionofeachsite.

4.2 ProductionoftablefishinRASinEnglandandWalesAnnualproductiondataforthedifferentRASfarmswasextractedfromthelivefishmovements

database(LFMD).ThiswassupplementedwithdatacollectedduringinterviewswiththeRASfarmers

(Figure2).

0

200

400

600

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Annualprodu

ction

(tonnesp.a.)

Welshseabass

Englishcatfish

Englishbarramundi

Englishtilapia

Figure2:AnnualproductionoftablefishinRASbyspeciesandcountry,fortheyears20002010.

Please

note

production

of

other

species

is

not

included

as

it

is

negligible.



11/51

Atthatstartofthedecade,RASproductionamountedto2tonnesofcatfish.Attheendofthe

decade,RASproductionwasover600tonnes,whichequatestoan80%p.a.increaseinoutput.

Productionin2010wascomprisedalmostentirelyofseabass(77%)andtilapia(23%).Therewasa

notableproduction(400tonnes)ofbarramundiin2008fromasinglefarm,whichthenceased

production.

4.3 RAScontributiontotablefishproductionAlthoughproductionfromRAShasincreasedmarkedly,itisstillonlyaminorcontributortotablefish

productioninEnglandandWales(Figure3).Tablefishproductionisdominatedbyrainbowtrout,

withRAS(allspeciescombined)contributingapproximately12%.Nevertheless,differenttrendsare

apparent:RASproductionhasbeenincreasingagainstabackdropofdecliningtroutproduction.

0

1000

2000

3000

4000

5000

6000

7000

8000

1994 1996 1998 2000 2002 2004 2006 2008 2010

Tonnesp.a.

E&Wtabletrout

E&WRAStablefish

Figure3:AnnualproductionoftabletroutandtablefishinRASinEnglandandWales1994201010.

4.4 TheRASindustryinEuropeAlthoughtherehasbeenanincreaseinRASproductioninEnglandandWalesoverthelast10years,

itcannotbeassumedthatthistrendwillcontinue.TheBeneluxcountriesandDenmarkhavea

similarclimate(andgeography)toEnglandandWales,andleadEuropeintheproductionoftable

fishinRAS11

.(PossiblecontributingfactorstoenthusiasmforRASfishfarming inthesecountries

are:adietwithatraditionalfishcomponent;lackofuplandareasforcool,cleanwatersupplyfor

salmonidfarming;coastlineinappropriateforcageculture;astrongenvironmentallobby;along

10Source:FHIproductionfigures,FinfishNewsandcollectedduringsurvey.

11MartinsCIM,EdingEH,VerdegemMCJ,HeinsbroekLTN,SchneiderO,BlanchetonJP,dOrbcastelER,VerrethJAJ(2010)New

developmentsinrecirculatingaquaculturesystemsinEurope:aperspectiveonenvironmentalsustainability.AquaculturalEngineering43,

8393.



12/51

standingeelfarmingsectorwhichusesRAS).Experiencesfromthesecountriesmeritconsideration

whenreflectingonthepotentialfuturedevelopmentoftheRASsectorinEnglandandWales.

IntheNetherlands,thefinfishaquaculturesectorisuniquewithinEuropeasitisbasedalmost

entirelyonthecultureofvariousspeciesinRAS.ProductionoftablefishinDutchRAS(ca.8,000

tonnesp.a.,Table3)exceedsthetotalproductionofalltablefish(flowthroughandRAS)inEngland

andWales(5,500tonnesp.a.,Figure3).

However,theDutchRASindustryhasshownaveryrecentdownturn.Thenumberoffarmshas

halved,andproductioncapacityhasreducedbymorethan16%within2years(Table3).Various

reasonshavebeenproposedforthisdecline12

:

issuesoverthesustainabilityofeelproductionduetodependenceonendangeredwildelvers

highproductioncostsforspeciessuchasturbot,soleandtilapia

novelspecies,e.g.whitelegshrimp,beingunabletoestablishinnichemarkets

Table3:Production(tonnesp.a.)ofthemostimportantspeciesinDutchRAS13.

Species

20072008 Expectedforendof

2009

%Change2007

08/2009

No.of

farms

Production No.of

farms

Production No.of

farms

Production

Eel 43 4250 19 29%

Africancatfish 18 3100 56 1000 6772% 68%

NileTilapia 4 840 0 0 100% 100%

Turbot 4 210 2 210 50% 0%

Barramundi 2 135 0 0 100% 100%

Pikeperch 2 130 3 130 +50% 0%

Doversole 1 10 1 20 0% +100%

European

catfish

1 100 2 3000 +100% +2900%

Totals 75 8775 33 7360 56% 16%

AtilapiafarmingprojectwaslaunchedinBelgiumin2006,whichclaimedtobethelargestRASinthe

world;theprojectcost15millionandplannedproductionwas3000tonnesp.a..However,itwent

intoadministrationin200914

,andthefailurewasattributedtodiseaseproblemsandthelowprice

ofcompetingfishproducts15

.

12http://www.oecd.org/dataoecd/19/21/45032957.pdf

13 TheDutchcaseforpracticesinfinfishaquacultureusingRAS,Schneider,Oetal,Abstractat8thInternationalrecirculatingaquaculture

conference.14http://www.fishnewseu.com/latestnews/world/2097endofthelineforvitafish.html

15http://www.fishnewseu.com/latestnews/world/1684priceofcodblamedforbankruptcyofvitafishtilapiafarm.html



13/51

4.5 ProspectsfortheRASsectorinEnglandandWalesTheDutchRASindustryproducingmorethan10timesthatoftheEnglishandWalesRASsector

indicatespotentialforfurtherexpansionintheUK.However,itmustalsoberecognisedthatDutch

RASproductionisdwarfedbycagefarmedsalmoninNorway(800,000tonnesp.a.)andScotland

(145,000tonnesp.a.)16

.Historically,RAShaveapoortrackrecordintheUK,withfewfarms

persistingformorethanafewyears;thisisnotuniquetotheUK.RASproductsmayalsohaveto

increasinglycompetewithcheapimports,suchasPangasiuscatfishfromAsia(alsoknownasbasa,

rivercobblerorpanga).Consequently,projectingthefuturesizeof,andproductionfrom,theRAS

sectorinEnglandandWalesisextremelydifficultwitheithergrowthordeclineforeseeable.The

commercialviabilityofRASintheUKwilllargelydependupondomesticdemandforRASproducts

andfarmgatepricesachievable.

4.6 ProspectsforRASuseintheScottishsalmonsectorScottishsalmonproductioncanbeviewedasa3stageprocess:thefreshwaterhatchery,freshwater

ongrowing(smoltproduction),andmarine(seacage)production.Allthreestageshavetraditionally

beenbaseduponopensystems:assalmonareacoldwaterspeciesanddonotneedadditionalheat,

openflowthroughsystemsaregenerallyacceptedasbeingmorefinanciallyviablethanRASculture.

However,duetoenvironmentalconcerns,thereisincreasingpressuretoproducesalmoninclosed

containment

systems

and

research

is

ongoing

in

North

America

17

to

develop

and

make

these

systemscommerciallycompetitive.IntheFaroeIslandsandNorwayfreshwaterproductionhasbeen

shiftingtowardsRAStechnologytoalleviateproblemsassociatedwithfreshwaterresources,i.e.

shortage,poorqualityandvariabletemperature18

.IthasbeensuggestedthatRASproductionoffers

benefitstotheindustrythroughimprovedfreshwatergrowthratesandsmoltquality(improved

survivalandgrowthratesonceinseacages)19

.However,arecentreportbytheScottishSalmon

ProducersOrganisation(SSPO)considerslandbasedRASforongrowingstagesnotfinanciallyviable,

withthehighenergyuseandcarbonfootprintmakingitanenvironmentallyunfriendlyoption20

.

162008Europeanfinfishaquacultureproduction.FinfishNews9,5455.

17http://www.fishupdate.com/news/fullstory.php/aid/15659

18MartinsCIM,EdingEH,VerdegemMCJ,HeinsbroekLTN,SchneiderO,BlanchetonJP,dOrbcastelER,VerrethJAJ(2010)New

developmentsinrecirculatingaquaculturesystemsinEurope:aperspectiveonenvironmentalsustainability.AquaculturalEngineering43,

839319Martinsetal.(2010)op.cit.

20http://www.scottishsalmon.co.uk/userFiles/885/Salmon_Annual_Report_2009(1).pdf



14/51

5 Technology, performance and operationof RAS

Arecirculatingaquaculturesystemisanartificialgrowingenvironmentthatrecyclesusedwater.As

waterisretained,RASpotentiallymakesheatingwaterforfishfarmingcosteffective21

. Awarm

waterRASallowstheproductionoftropicalspeciesincoolerclimates.Itmayalsobeusedfor

temperatespecies:asfisharecoldbloodedanimals,growthrateislinkedtotemperature,so

increasingthewatertemperatureaboveambientincreasesgrowthandproduction.

Waterqualitydoesneedtobemaintainedtoprovideoptimumconditionsforfishgrowth,and

assurefishhealthandproductquality.Thisisachievedbyremovingthewasteproducts(uneaten

food,faecesandexcretedmetabolites)bytreatingthewaterusingfiltrationandcleansing

technology.Thesystemwaterpassesthroughthetreatmentprocessmanytimesperday,ata

recirculationratetypicallyequatingtoonesystemvolumeevery1to2hours.Inaddition,a

percentageofthetotalvolumemustbereplacedwithnewmakeupwatertopreventexcessive

buildupofnitratesanddissolvedorganiccompounds.WhenRASsystemswerefirstbeing

developed,theyweredescribedintermsofthevolumeofwaterexchangedduringeachcircuit(e.g.

10%ofsystemvolume/pass).CurrentRASrequiremuchlessmakeupwater,andaredescribedby

thedailyreplacementrate(e.g.5%systemvolume/day)22.

AlthoughRASofferanumberofadvantagesasdescribedaboveandintheIntroduction,theyalso

sufferfrompotentialdrawbacks:

largesetup/investmentcosts,withaneedforbackupsystems.

highrunningcosts

productionlimitedbythecapacityofsystems:theloadthatfilterscanprocesswilllimitthe

productionofaRAS

shorttermincreasesinfishproductionarelimited: thebiofilterneedstimetoadaptand

changecapacitytodealwithwastes

experiencedstaffareneededtorunRASwhichactaslifesupportsystems

5.1 ThefundamentalsofRAS

21LittleDC,MurrayFJ,AzimE,LeschenW,BoydK,WattersonA,YoungJA(2008).OptionsforproducingawarmwaterfishintheUK:limits

togreengrowth.TrendsinfoodScience&Technology19,255264.22http://www.slideshare.net/Cefas/largescaleintensiverecirculationsystemsandtheirpotentialdevelopmentwithinengland2373881



15/51

InRAS,thewaterfromtheproductionunitsistreatedtoremovesuspendedsolidparticles(uneaten

food,faeces),toremoveorconvertdissolvedchemicalwastesandgasses(e.g.ammonia,nitriteand

CO2)andtoincreasedissolvedoxygenlevels,beforereturntotheproductionunits. Thefiltrationis

carriedoutbytwomainprocesses:

Mechanicalfiltration,wherebythesuspendedsolidsareremoved(c.f.asieve)

Biologicalfiltration,wherebythedissolvedsubstancesandorganicchemicalwastesare

convertedtolesstoxicsubstances.Biologicalfilters,throughtheirdesign,usuallyalso

increaseoxygen,andreducecarbondioxide,levels.

RASmayalsouseadditionalprocesses:aeration/oxygenation,sterilisation(toremovepathogens

andundesirablebacteria),chemicalbuffering(ofwaterqualityparameters),etc. Theseadditions

dependontherequirementsandtheloadingofthesystem23.AlthoughloadingofRASisoften

consideredintermsoffishbiomass,itisprimarilytheamountoffoodthatisthelimitingfactor24

:

foodmassdictatesthemetabolicrate(andoxygenrequirements)ofthefish,therateofwaste

production,andthefishbiomassthatcanbeheldinthesystem.

Figure4:Featureofrecirculationaquaculturesystems

23withaerationstockingdensitiesof5060kg/m

3(50kg/m

3isthemaximumcapacityusedinthedesign)canbeachievedwhilst

maintaininghighfishwelfarestandards.Higherstockingdensitiesupto120kg/m3canbeachievedwiththeuseofoxygenTilapiainfo

packUniversityofStirlinghttp://www.tilapiascotland.org/resources24Ellisetal.(2010).Sustainablefinfishaquacultureworkshop.FinfishNews9,422.

Production units

Mechanicalfiltration

Sterilisation

Water eitherpumped orvia gravity

Waterreturn bygravity

Oxygenationand/ or aeration

Water pumped tonext stage

Chemicalbuffering

Biologicalfiltration

Additionalapplications

Basicprocesses

http://www.tilapiascotland.org/resourceshttp://www.tilapiascotland.org/resourceshttp://www.tilapiascotland.org/resources


16/51

5.2 MechanicalfiltrationWhatevertheRASdesign,theremovalofsuspendedsolidwaste(SSW)bymechanicalfiltrationis

oneofthemostimportantpartsofwatertreatment.Alldesignsshouldaimtokeepsolidwastesas

intactaspossiblepriortomechanicalfiltration.IfSSWarebrokenup,thesmallerparticlesarenotas

easytosieveout,andthelargersurfaceareafacilitatesdissolvingofsolubleorganiccompounds.

Dissolvedorganicsaddtotheloadonthebiologicalfilterandencouragethegrowthoflessdesirable

heterotrophicbacteriawhichincreasetheoxygendemandofthesystemandcompetewiththe

nitrifyingbacteriainthebiofilter.

TherearemanytypesanddesignsofmechanicalfiltrationtoremoveSSW,suitedtodifferent

operatingsystems. Thetwokeyfactorstoconsiderwhenselectingmechanicalfiltrationare:

theexpectedSSWloading

theflowrateofwaterthatthefilterwillhavetoprocess.

ThemechanicalfiltershouldremoveSSWasquicklyaspossiblewithoutdamagingtheparticles.

Variousmechanicalfiltrationmethodsareavailable:

drumfilters

screen/beltfilters

beadfilters

sandfilters

vortex/settlementfilters

ForlargescaleRAS,onlydrumfiltersofferapracticalmethodforremovinglargequantitiesofSSW

atahighflowrate.Drumfiltershavetheaddedadvantagethat,dependingonthescreenareaand

meshsize,ahighpercentageofSSWcanberemoved. Screen/beltfiltersaregenerallydesignedfor

lowflowrates.Intheotherthreemethods,SSWaretrappedinthefilterbutnotremovedfromthe

systemimmediately,whichallowsleachingofsolubleorganiccompounds.Thelatterfourmethods

arethereforegenerallyonlysuitedforsmallerRASorthosewithalowloading.

Industryobservations

AllsitesvisitedrecognisedthatpromptremovalofSSWwasanimportantfactor.Approximatelyhalf

ofthesitesuseddrumfilters.Althoughtheygenerallyhadnoproblems,oneissuewasinappropriate

selectionofdrumfiltersbythesystemdesigner,i.e.undersizedfiltersortoofinemeshinscreens,

whichresultedinthedrumfiltershavingtorunconstantly.Constantcleaningofdrumfilterscreens

requiresahighwaterusageand,wheretapwaterwastheonlysupply,thisbecameasignificant

cost.Nevertheless,thisprovidedtherouteforwaterexchangefortheRASand50%ofthesesites



17/51

installedawaterrecoveryprocessfordrumfilterscreenwashing. Asdrumfiltersareexpensive,

mostRAShadtobeoperatedasasingleunitratherthanseveraldiscreteunits;thiswashighlighted

bysomefarmersasundesirable,asithasimplicationsfordiseasespreadandcontrol,andtherewas

lessflexibilityinthesystem.

ThreesmallersiteshadusedalternativessuchasbeadfilterstoremoveSSW.However,asthe

quantityoffish(andfeed)increased,thesefilterscouldnotcopewiththeSSWloading,andwere

typicallyreplacedwithdrumfilters,whichwasacostlyprocess. Twositesusedscreen/beltfilters;

althoughonefoundthemgenerallyadequate,theothersitehighlightedthemasamajorproblem

theywereinadequatefortheirroleandrippedandfailedonaweeklybasis. Thereplacement

screenscouldonlybesourcedfromaspecialistsupplierandprovedveryexpensive(1,8002,000

ea)andtimeconsuming(taking3menhalfaday)toreplace. Onesiteusedvortex/settlement

methodstoremovesolidsandfoundthisadequateatthemodestscaleofproduction,providedthe

solidswerebackwashedoutregularly.

5.3 BiologicalfiltrationBiologicalfiltersaregenerallyplaceddownstreamofthemechanicalfiltersotheydonotbecome

cloggedwithSSW.Nitrifyingbacteriawithinthebiofilterconverttoxicammoniatonitrite,andin

turnnitrate25

.Thebasicprincipleofbiologicalfiltrationistoprovideasurfacefornitrifyingbacteria

togrow.Thisisachievedbyusingasubstratumwithaveryhighsurfacearea:volumeratioto

maximisetheamountofbacteriawithinalimitedspace.Therearemanydifferentdesignsof

biofilter:theinstallationofofftheshelfsystemsistheexception,andmosttendtobebespoke.

Manybiofilterscombineasubmerged(wet)stageandatrickle(nonsubmerged)stage. The

submergedstageusuallycomprisesavesselcontainingplasticfiltermediaspecificallydesignedfor

itshighsurfaceareawithaflowpassingthroughthevessel. Mostdesignsalsousestrongaerationto

constantlymixthemedia(afluidisedbiofilter)whichgivesvariousbenefits:

filtermediaiskeptclean,preventingSSWsettlementandheterotrophicbacteriabuildup

mixingensuresallmediaisutilisedbynitrifyingbacteria

increasedoxygen(O2)levelswithinthefilterensuresahigherconversionofammoniatonitrite

andinturnnitrate(nitritetonitraterequiresahighO2environment).

CO2andanyotherundesirablegassesaresloughedoffbytheaeration

25ammoniaispresentintwoforms free(NH3)whichisverytoxictofish,andionized(NH4

+)whichisstilltoxicbutlessso.Thehigherthe

pH,thegreatertheratioofthemoretoxicfreeformtotheionizedform.Nitrosomonasbacteriaoxidizeammoniaintonitrite(NO2)bytheadditionofoxygen,andNitrobacterbacteriaoxidizenitriteintonitrate(NO3

).Thesetwotypesofbacteriaarereferredtoas"nitrifying

bacteria,"http://www.pondsystems.com/news_biofilt.html#TheNitrogenCycle



18/51

O2levelsinthewaterareboosted(forreturntothefish)

Trickle(nonsubmerged)filtersagainmakeuseofspecificmediabutthesearefreestanding,either

withinavesselorstackedwithcurtainsides,ratherthansubmerged. Tricklefiltersaregenerally

positionedafterafirststagesubmergedfilterandoftenusegravitytofeedwatertothetopofthe

filterwhichthensimplytricklesdownthroughthemedia. Themainadvantageofatricklefilteris

thehighsurfaceareaincontactwithairwhichallowsbothdegassingandaerationofwaterand

providesanoxygenrichareatocompletetheprocessofconvertingammoniatonitrate.


Approximately60%ofsitesvisitedusedfluidisedbiofiltersofvariousdesignsandcapacities.One

commercialmedia(KaldnessK1plasticmedia)wascommontoallsystems.Sitesproducingtilapia

justusedasubmergedfilter(notricklefilter).AllseawaterRASusedtricklefilters,andnoissues

werehighlightedwiththese.

Acommonfindingwasoverexpectationofperformanceofbiofiltersintheoriginalsystemdesign,

withtheinstalledbiofilterfailingtodeliveranticipatedperformance.Nearlyeverysitehadto

increasebiofiltercapacitybyaddingmoremediaand/orincreasingthefiltersize.Factorsthat

contributed

to

reduced

performance

were:

inadequatemechanicalfiltration,soSSWaddedtothebiofilterloading

lowerthanexpectedoxygenlevels

inadequateflowratesthroughtheRASwhichallowedammoniatobuildupinproductionunits

andreachthebiofiltersatahighlevel.(UnprocessedSSWcouldalsobuildup).

deadspotsinfilters.

5.4 Aeration/oxygenationAdequateoxygenlevelsareobviouslycriticalforfishproduction,healthandwelfare,aswellas

biofilterperformance.Variousmethodsareemployedrangingfromaerationviadiffusersdelivered

fromacompressor/blowertotheapplicationofpureoxygenviafinediffusersorinjectionsystems.

Carehastobetakenwiththeapplicationofpureoxygenasoveroxygenationispossible;an

automaticmonitoring/controlsystemthatdosesthecorrectamountisrequired. Itispreferableto

applyoxygeneitherdirectlytotheproductionunitortothereturnwaterratherthanthewholeunit.



19/51


Allsitesusedaerationasthemainsourceofoxygen,andalsotooperatefluidisedbiofiltersand

opposingflowproductionsystems(whereaerationcreatesopposingcircularcurrentsalong

productionunitsinordertodistributefishmoreevenly). Severalsiteshadneededtoincrease

aerationabovethatoriginallydesignedandinstalled. Atleastonesitehadexperiencedthetotalloss

ofabatchoffishwhichwasattributedtolowoxygenlevelsduetoinstallationofaninadequate

aerationsystemwhichhadsincebeenupgraded. OnesitemoveditsairblowersoutsidetheRAS

buildingtoreducehumidityandimproveturnoverofairandreduceCO2buildupwithinthewhole

building. Onesiteinstalledahydrogenperoxidedeliverysystemforbothroutineandemergency

oxygenation,whichwasconsideredtobeasimpleandeconomicalsolutionforthatsite.

5.5 HeatingHeatingcanobviouslybedeliveredinnumerousways;spaceheaterswereusedbythe65%ofsites

asitisgenerallyconsideredmoreeconomicaltoheattheentireunitthanjustthewater.This

assumesthatthebuildingiswellinsulated.Thespacetoheatisthereforeafactortoconsiderinthe

initialdesign:thereshouldnotbeanexcessivespace(airvolume)toheat,althoughthereshouldbe

sufficientexchangetopreventCO2buildup. Nevertheless,approximately80%ofunitsusedpre

existingbuildingssotheairspacedwasalreadyfixed;onesitehadinstalledlowerceilingstoreduce

it.

At

60%

of

sites,

space

heaters

were

situated

in

the

main

production

building;

however

3

sites

had

movedthemoutsidethebuildingtodirectfreshairintothebuildingandprotecttheheatersfrom

thehumidenvironmentinsidetheRASbuilding.

Onesiteusedtheheatgivenoffbyonsitegenerators. Heatrecovery(fromwastewateror

ventilatedair)wasinstalledatseveralsites.Onesiteexpendedconsiderableeffortinrecovering

dischargedheattoreduceheatingcosts,and4ofthelargersites,whereheatingwasrecognisedasa

significantcost,wereexploringheatrecovery.

AlmosteverysitesituatedheadertanksfornewmakeupwaterinsidetheRASunitsoitcouldwarm

up,butoftenthewaterwasincirculationbeforeithadreachedtemperature.

5.6 Sterilisationofinlet/returnwaterWaterissterilisedtokillpathogens,removeundesirableheterotrophicbacteriaandimprovewater

quality.ThetwomainmethodsareexposuretoUVlightandozone.Bothmethodshavetheir

advantagesanddisadvantagesandsuitabilitydependsonthesituation. UVisgenerallythecheaper



20/51

option,butisonlyeffectivewithclearwater;inturbidwaterpenetrationofUVisinsufficient. Ozone

ismoreexpensiveandhasobvioushealthandsafetyimplications,butitismoreeffectiveandworks

inturbidwater.Ozonemayhavetheadditionalbenefitofimprovingwaterqualitybyremoving

flavourtaintssuchasgeosmins26andorganictoxins.InseawaterRAS,ozoneisoftencombinedwith

proteinskimmerstoboosttheirperformanceinfractionalremovalofproteins.Onesiteusedozone

todisinfectincomingwaterwhichwasdrawnstraightfromsea.

5.7 PumpingPumpingofwatertoensurecirculationofwaterwithinRASisobviouslyanextremelyimportant

factorforbothdesignandoperation.Therightpumpneedstobeselected:undersizedpumpsresult

inapoorturnoverinthesystemandleadtounderperformingfilters,waterqualityissuesand

reducedproduction.Oversizedpumpsareuneconomicaltorun. Thereisawidevarietyofpumps

availablefordifferentpurposes:

highpressurepumpsaremoresuitableforaringmainsystem

liftpumpsaresuitedtomovinglargevolumesofwaterbutwithlittleheight(head)

sludgepumpsaredesignedtomovehighlyviscoseliquidsladenwithsolids.

Approximately30%ofsitessaidtheyhadthecorrecttypeandsizeofpumpsinplace.Asmall

numberofsiteswouldhavepreferredtohaveaseriesofsmallerpumpstogivegreaterflexibilityin

thesystemandactasbackupsincaseoffailure. Three(cooperating)sitessharedasparepumpas

contingencyforpumpfailure.

5.8 TanksTankandholdingsystemsvariedacrosssites.However,themostcommontypesfortilapiaunits

wereabovegroundrectangularconcreteorfibreglassraceways.Marinesitesmostlyoperatedeither

circularorhexagonaltankswithonelargesiteconstructingtankspartiallybelowgroundlevel.

Smallersitesusedavarietyofcircularfibreglassholdingunits. Depurationtanksusuallyinvolveda

separatefiltrationsystemusingnewcleanwatertosupplysmallerfibreglasstanks.

5.9 PipeworkPipeworkisoftenoverlookedwithinthedesignofanRAS.Inadequatepipeworkandfittingcanslow

flowrates. Itisdifficulttocleanclosedpipeworkso,wherepossible,openchannelsshouldbeused

26SchraderKK,DavidsonJW,RimandoAM,SummerfeltST(2010).Evaluationofozonationonlevelsoftheoffflavourcompoundsgeosmin

and2methylisoborneolinwaterandrainbowtroutOncorhynchusmykissfromrecirculatingaquaculturesystems.AquaculturalEngineering43,4650.



21/51

toenableroutinecleaning,especiallyfordirtyreturnwater. Atoneofthesites,deepchannels

returnedwastewaterataslowratetothefilters:thisallowedSSWtosettlewhichaddedto

maintenanceandleachedorganiccompoundswhichincreasedbiologicaloxygendemand.The

inappropriatelocationofpipeworkcancauseoperationalissues:at2sitesitwaspositionedontop

oftheproductionunitswalls:thisreducedaccessandwasthereforeconsideredapoordesign.

Overhalfofthesiteshadchangedpipeworktoimprovesuchaspects,whichrequiredextratimeand

expenditure.

5.10 MonitoringsystemsAlarmedmonitoringsystemsareobviouslyacriticalpartofanyRASdesign.Incomparisontoa

simpleopen/flowthroughfishfarm,therearealotmoretechnologicalcomponentsthatcanfail,the

responsetimeisshorter(duetotypicallyhigherfishdensities),andthereislikelytobemorethan

oneissuetoresolveifsystemsstop.Acomprehensivealarmsystemshouldcoverelectricitysource,

allpumpsandtheiroutput,otherkeyequipment,oxygenlevelsinall(oratleastthelargest)

productionunits,andpH.Thealarmsystemshouldbelinkedtodialoutcontrol.

Nearlyallofthesitesdidhavealarmsystemscoveringtheelectricitysupplyandpumps,butdiffered

inwhatelsewascovered. Allbuttwositesdialledouttoalistoftelephonenumbers;theexceptions

used

an

onsite

audible

alarm

with

the

disadvantage

of

requiring

personnel

to

be

within

ear

shot.

5.11 AutomaticfeedingsystemsAutomaticfeedingsystemswereusedonrelativelyfewsites.Theseweresuggestedasbeneficialby

freeingupstafftimeandallowingfeedingtobecontrolled(amountandtiming)whichcanbe

importantforensuringconsistentwaterqualitywhenrunningRAS.

5.12 Watersources,replacementanddischargeThefreshwatersitesvisitedwereeitherusingmains,springorboreholewaterandweretypically

onlyreplacingbetween1to10%ofsystemwaterperday.Twocoastalseawatersitespumped

seawaterashore,whilsttheotherinlandsitesmixedtheirownfrompurchasedsaltandmainswater.

Theseawatersitesreplaced210%ofsystemwaterperday.

Dischargeofreplacedwater(usuallydrumfilterbackwash)wasmostcommonlytoasettlementtank

orlagoonandoccasionallytoasewer.Anyexcesswateraftersettlementwasdischargedtoamains



22/51

sewer,intoaconstructedwetlandareaordrainageditch.Theconcentratedsettledsolidswere

disposedofbyspreadingontofieldsorbeingtakenawayforoffsitedisposal.

5.13 LessonstobelearntThemajority(80%)ofsitesthatusedapreexistingbuildinghadtoaccommodateaspectsofthe

buildingdesign(e.g.lowceilingsandsupportpillars)intothesystemlayout.Thedisadvantagesof

usingapreexistingbuildingwillbesitespecific,andmustbebalancedagainstthecostofacustom

madebuilding.

RASmustbeconsideredasaselfcontainedecosystem,withthebiofilteratitscore.Akeyfactorthat

washighlightedbysomeofthesitesisthatRASmustberunasfixedoperations,i.e.inputs(i.e.

feed)andoutputs(harvest)mustbeconsistenttoensurereliableproduction.

ToensurethattheproductionpotentialofaRASisreached,itmustbedesigned,constructedand

operatedwell.Everysitevisitedrecognisedthatdesign,constructionanduseofcorrect/adequate

equipmentwereextremelyimportantinrunningaRAS:wheretherehadbeenfailures,aproblem

withoneofthesefactorshadbeenamajorcontributor.

A

high

percentage

of

sites

identified

poor

design

of

the

RAS

itself

as

the

main

cause

of

ongoing

issues:thesetendedtoemergeasthebiomassintheRASincreased,andrequiredaconsiderable

amountoftimeandmoneytoaddress. Examplesofdesignerrorswere:

ammoniabuildupinproductionunitsduetoinadequatewaterflowthroughthesystem

oxygenlevelsbecominglowasbiomass/feedingrateincreasedduetoinsufficientaeration

pHdroppingcausedbyCO2buildupduetoinadequateventilation/aeration(couldalsobe

addressedbybuffering)

onesitestoppedusingaventurideliverysystemasthiswascausinghighlevelsofO2

(supersaturation).

MakingchangestoRASonceinuseisobviouslyundesirable: ontopoftheadditionalcost,itis

logisticallydifficultandcancompromiseproduction. Somefundamentalflawscouldnotberectified

withouttotalshutdownoftheRAS,whichwasnotarealisticoptionforarunningbusiness. Onesite

didhavetoresorttototalshutdowntoaddressfailingdesignandpoorconstruction,whichpushed

thebusinesstowardsfinancialfailure.



23/51

Approximately60%ofRAShadbeendesignedtorunasonelargesingleunit.Althoughthismay

economiseonconstructioncosts,itwasrecognisedasacompromiseasitmakessystemsinflexible.

Anexampleiswhensmallfryneedtobeongrown(ratherthanfingerlings) fryrearingfacilities

separatetothemainproductionRASneededtobesetupbysomesites. Inhindsight,approximately

30%ofsiteswouldhavepreferredsmaller,separateRASdespitetheadditionalcapitalinvestment

required,togivegreaterflexibilityandmanageability,particularlywhilenewbusinessventureswere

findingstheirfeet.

RASoftenseemtobedesignedtorunatthelimitofcapacity,withfiltrationjustadequateto

managethemaximumbiomass/feedloadingonasystem. RunningaRASatthislevelleavesno

margin forfluctuationsinwaterquality,errorinpractices,maintenance,andforunforeseenevents

suchasequipmentfailure.Therealityisthatthingswillnotproceedsmoothlyatalltimes,andspare

capacitydoesneedtobebuiltintothedesign.

Sitesthatconstructedvessels(forfishandfilters)ofconcretewereparticularlyrestrictedcompared

tositesconstructedoffreestandingvessels. Concreteproductionunitsweregenerallyofaraceway

design,butonesiteusedlargeconcretecirculartanks.Modificationstothefiltrationunits,

frequentlyidentifiedassitesapproachedtheirexpectedmaximumbiomass(andfeedingrate),were

particularly

difficult

and

restricted

if

constructed

from

concrete.

However,

concrete

may

be

the

only

viableoptionforlargeRAS.Notably,atonelargesiteconstructedofconcrete,thefiltrationhadbeen

carefullydesignedandwasworkingwellwithinexpectedparameters.

Forgettingoperationconsiderationsduringdesignledtotwocommon,andpotentiallyimportant,

designflaws:

storagecapacityforinletwaterisoftenunderestimated,somakeupwaterdoesnothave

sufficienttimetowarmuptotemperaturebeforeuse

alackofcapacitytoretainwaterwhentanksneededtobedrainedforharvestormaintenance.

Ifdrainedtankwaterislostfromthesystem,thenitmustbereplaced.Replacementmay

representasignificantcostintermsoflostwaterandheat,ontopofthetimeforreplacement

(particularlyiftapwateristheonlywatersource).

Examplesofotherdesignflawsrelatedtoignoringhowstaffwouldaccessareas,conductroutine

activitiesandmaintenance:

pipesfittedtotopsofwallspreventedaccessalongthem



24/51

hexagonaltanks,neatlyfilledspace,butpreventedaccesstothoseinthemiddle

awalkway,postfittedtoprovideaccess,necessitatedstaffhavingtooperate4mabovethe

watersurface,makingactivitiessuchasmortalityremovalverydifficult.Thistrickyoperation

wascompoundedbytheoutletsbeinginstalledatthebottomofthevessels.

tankshape(e.g.hexagonalwithawkwardcorners),makingconfinementofthestockdifficult

duringharvest

lackofanyprovisionindesignformechanisedharvest,necessitatingmanualhauling.

InconclusionthemajorityofRASoperatedwellandproducedfishoncetherightcombinationof

mechanicalandbiologicalfiltrationwasinplace.Sitesthatachievedtherightfiltrationfromthe

outsetwereaminority;mostrequiredconsiderableadaptationandmodificationstoapoorinitial

design.Underestimatingfiltrationcapacityfortheproductiontarget(=overestimatingproductionfor

thedesignedfiltrationcapacity)wascommon.Whetherinitialdesignwasgoodorbad,changes

alwaysneededtobemade;minorchangescanbeaccommodated,butlargeunforeseenchangescan

provecostly. Poorconstructionwasaproblemforsome,butnotall,sites.

5.14 NextgenerationRASActiveresearchisongoinginEurope,NorthAmericaandelsewheretofurtherdevelopRAS.Progress

isbeingmadeinareassuchasdenitrificationreactors,sludgethickeningtechnologiesandozone

treatments.Thesewillallcontributetoreducingwateruse,wastedischargeandenergyuseinRAS

(recentlyreviewedbyMartinsetal.2010)27

.However,whilstsuchdevelopmentsofferpromisefor

thenextgenerationofUKRAS,theyarenotyetwidelyavailabletotheexistingsector.

Nitrogenouswasteremoval:Twonewapproachesarebeingappliedtoremovenitrogenouswastes

fromRAS.Thefirstisbasedonrecentdevelopmentsindeammonificationinotherwastewater

treatmentapplications.TheEUFP7DeammRecircprojectisdevelopingdeammonificationreactors

forfresh andseawaterRAS,whichconvertammoniatonitrogengasinonestep.Ifthetechnology

isproven,deammonificationreactorscouldbenefitcommercialRASbyreducing:theneedforclean

makeupwaterandassociatedpumpingandtreatmentcosts,oxygenandbufferingchemicaluseand

cost,carbonfootprint,andlevelsofnitrateineffluent28

.Thesecondapproachisdenitrification

reactorswhichremovethenitratethatbuildsupinRASbyconversiontonitrogengas.Varioustypes

ofdenitrificationreactorshavebeendevelopedthatallowhighnitrateconcentrationstobe

27

Martinsetal(2010)NewdevelopmentsinrecirculatingaquaculturesystemsinEurope:Aperspectiveonenvironmentalsustainability,AquacultureEngineering43(2010)8393.28http://deammrecirc.com/Project Description



25/51

counteracted,e.g.theupflowsludgeblanketdenitrificationreactor.Martinsetal(2010)discussthebenefitsofthesesystems andsuggestthat installationcostsarerewardedbyloweroperatingcosts

duetoreduced waterexchange.However,boththesenewapproachestoremovenitrogenand

reducewaterreplacementmayprecipitateotherproblemssuchasaccumulationofgrowth

inhibitingfactors(anareathatrequiresfurtherresearch).

Suspendedsolidswastetreatment:Sludgethickeningtechnologiessuchasbeltfilters,geotextile

bagsortubesallhelptodewaterandreducethevolumeofSSWthatneedsstorageanddisposal.

Thesetechnologiesmayalsochangethewasteintoaformmoresuitableforuseasafertiliserorin

integratedaquaculture.

Effluenttreatment:Constructedwetlandsandmicroalgalcontrolledsystemsarecommonlyusedto

treatmunicipalwastewaterandofferopportunitiesfortreatmentofwastewaterfromRAS.

Energyefficiency:ResearchbeingcarriedoutattheFreshwaterInstitute(Virginia,USA)on

improvingthesustainabilityoflandbasedclosedcontainmentsystemsforsalmonidtablefish

productionistargetingthepotentialforgreaterenergyefficiencyinwaterrecirculationsystems

throughimprovedlowliftpumpingandgastransferprocesses.TheUSDepartmentofAgriculture

scientistshaveshownthatacombinationoflowheadpumps,properplumbingandlargerdiameter

pipesused30%lessenergythanhighheadcentrifugalpumps.



26/51

6 Financial sustainability of RAS

Theaimofthissectionistoprovideanoverviewofthefinancialexperiencesofthe14different

warm

water

RAS.

It

should

be

noted

that

the

extent

and

detail

of

the

financial

data

provided

varied

betweenintervieweesduetoconfidentiality,positionwithinthebusiness,andavailablerecords.

6.1 FundingsourcesFundingoftheoperationsvariedconsiderablybetweenbusinessesfromthosewhojustusedtheir

ownmoneytomixturesofinvestorfunding,bankloans,mortgagesandgrants. Approximatelyhalf

hadborrowedinoneformoranothertogetthebusinessupandrunning.Fewerthanhalfthesites

hadobtainedsomesortofgrantfunding:grantsvariedfromaslittleas1,000tomany100,000s

forthelargestsites.Accesstocontingencyfundingwasmentionedasimportantbyonesite.

6.2 BuildandsetupcostsThescaleofthesitesvisitedvariedfromthosecosting70,00080,000builttoproduce1050

tonnesp.a.,tositescosting10to14milliondesignedtoproduce1,000tonnesp.a..

Underestimationofthebuildandsetupcostswascommon,withfiguresforoverspendvarying

between15and40%.Thereasonsgivenvariedandincluded:

designsnotincludingcostofinstallationofspecificelectricalsupplies

additionofsupplementarydenitrificationfilters

modificationstofaultysystems.

6.3 RunningcostsElectricity:Mostofthesitesvisitedconsideredelectricitytobeamajorcost:typicalfiguresquoted

were15 20%ofrunningcosts.Monthlycostsof500 1000weretypicallyquoted,evenbysites

producinglessthan100tonnesp.a. Somesitesexpressedconcernthatinappropriate,power

hungrypumpshadbeensupplied,whichunnecessarilydoubledtheelectricitybill. Somesiteswere

investigatingtheuseofalternativeenergysources.

Heating:Thenecessityforsupplementaryheatingvariesbetweensitesandwithspeciesheld.

However,mostsitesconsideredthatheatingwasaminorcost,andthelargestsitedidnotconsider

heatingasignificantcostatall. Figurestypicallyquotedwere5%ofrunningcostsor50%ofpumping

costs.Withgoodinsulation,alotofthesitesonlyusedsupplementaryheatingfor2 4monthsin

winter.Somesmallersitesfoundcheaperalternatives,e.g.



27/51

burningwoodchip

switchingfromanLPG(liquidpropanegas)heatsourcetodiesel.

Water:Agoodsupplyofwateriscriticalevenforarecirculationsystemasitisrequiredfortopup,

emergencyuse,shippingetc. Waterquantityandqualityissuesmustberesolvedbeforelocatingan

aquaculturefacility29

.Themajorityofsiteshadnoissueswithsupplyandoftenbenefittedfrom

agriculturalrates. Watersupplycostsdidnotrepresentasignificantproportionofrunningcostsfor

themajorityofsites. However,asmallnumberofsitesdidexperienceunexpectedwatercosts,e.g.:

aswitchtomainswatersupply

makingupsaltwateronsite,costingupto2.10perm3

underestimatingthecostofpumpingwaterfromthesourceintothefarm.

Staff:Responsesvariedbetweensites:somethoughtstaffcostswerenothigh,whileothers

emphasisedthetimecommitmentinrunningRASandtheneedfortrained,experiencedbackup

availableatalltimes.Onesite,betweendevelopmentphases,didexpressconcernaboutthe

intensityofmanpowerrequired.Entrylevelpayintoaquacultureisacknowledgedtobelow30

and

manysiteshavebenefittedfromcheapeastEuropeanlabour. Twolargersites,inoperationwith

goodfinancialmanagementsystems,bothestimatedstaffcostsat15%ofrunningcosts.

Fry:Ofthe14RASsitesvisited,5hadsourcedUKfryandonehadusedtheirownbroodstock,while

10hadimportedeggsorfry. SomesiteshadongrownbothimportedandUKfry.Frysupply

thereforefrequentlynecessitatedimports,duetoalackofUKhatcheries.Fryhadbeenimported

fromFrance,Holland,Israel,USA,SouthAfricaandIndonesia.Themethodofshippingvaried:road

deliveryfromEuropeancountriesandairfreightfromfurtherafield.Althoughfrywouldhavebeen

movedatasmallsize,transportinwateraddstoshippingcosts. Onelargersitestatedthatfrycosts

were8%oftotalrunningcosts.

Feed: Thepriceofaquafeedwasaconcerntoallbusinessesandcomprisedasizeableproportionof

runningcosts.Theactualcostsoffeedsvariedbetweenthespecies,anddidnotcorrelatewiththe

percentageofrunningcostsquoted,varyingbetween20%and40%ofrunningcosts.Factors

thoughttocontributetorelativedifferencesbetweensitesincludeeconomiesofscaleinfood

purchase(bulkbuying),howmuchthefishwerefed(%bodyweightperday),aswellasthe

magnitudeofothercostcategories. Issuesaroundfeedcostsincluded:

29http://www.aces.edu/dept/fisheries/aquaculture/documents/Wheaton.pdf

30http://www.sparsholt.ac.uk/pages/template.aspx?idSection=69&idPage=139

http://www.sparsholt.ac.uk/pages/template.aspx?idSection=69&idPage=139http://www.sparsholt.ac.uk/pages/template.aspx?idSection=69&idPage=139http://www.sparsholt.ac.uk/pages/template.aspx?idSection=69&idPage=139


28/51

largeincreasesinfeedpricesoutsidefarmercontrol

aswitchindietsnecessitatedbynutritionalproblemswhichincreasedfeedcostsfrom1,000to

1,600/tonne.

onetilapiafarmer,experiencedinsourcingterrestriallivestockfeedexpressedfrustrationatan

inabilitytosourcehisowningredientsandconsideredthataquafeedsupplyoptionsweretoo

limited.

producersofturbotandbarramundiexperiencedproblemsinsourcingappropriatediets

becausetheyweretheonlymarketintheUK.Thisalsomeanttherewasnochoicein

formulation.

Maintenance:Thereliabilityofequipment,itslifespanandthemaintenancecostsneedstobe

knownandassessedbyalloperatorspriortopurchase.Examplesofmaintenancecostissuesraised

are:

Pumpmaintenancecostswerehighlightedbyseveralsites

Onelargefarmhadtoreplacefilterbeltsonanalmostweeklybasis.Thistook3mendayeach

andcost1,800 2,000atime.Althoughacheaperbeltsupplywaseventuallyfound,thetime

andcostshadalreadyhadacripplingfinancialimpact.

Solidswaste

disposal:

Disposalofsettledsolidsfrommostfreshwaterrecirculationsystemswasnot

seenasasignificantcostastheywereabletospreadontofields.(Somesitesdidmentionthatthe

systemsadoptedhadincreasedtheirassociatedpumpingcosts). However,forsaltwatersites

disposalwasfarmorecomplicatedduetothepresenceofsalt.Foronesitepumpingoutthe

settlementtankapproximatelyeverytwomonthscost1,500atime.Inaddition,regulatorshave

notappliedpolicyuniformlyacrossregionswithsomefreshwatersiteshavingtheirwaste

categorisedasindustrialwastewhichrequiresaspeciallicensecosting4,000p.a..

Mortalitydisposal:Disposalofmortalitieswasconsideredaminorissuebysomesitesthathad

readyaccesstofacilities,whileotherssuggestedthatitincurredasignificantcostalthoughthiscould

notbequantified.

Rental:Over90%ofthesitesownedtheirownbuildingsoconsequentlyrentalcostswerenotan

issueandalmostallofthesehadutilisedexistingvacantbuildings. However,foronelargersite,

rentalcostswereconsideredexcessiveatapproximately25,000permonth.



29/51

Oxygen:Oxygenwasnotusedatmanyofthebusinesses,butdidamounttoupto5%ofrunning

costsatsomesites.Onefarmmentionedhydrogenperoxideuse,butthiswasnotconsidereda

majorcost.

Unexpectedcosts:Sitesoftenfoundrunningcostsweregreaterthaninitiallybudgeted,which

occurredduetoavarietyof,oftensitespecific,reasons:

salescosts(formarketing,packaging,icemachinesanddelivery)werecommonlywrongly

anticipated.Onesitequotedsalescostsat0.25/kgoffish.

supermarketcompliancecosts

modificationofnewlyinstalledsystemsandadjustmentstotechnology,e.g.deliveringadditional

ozonetoproteinskimmers.Therewastypicallyasignificantadditionalsetupcosttoaddress

teethingtroubles.

Biofilterscouldrequireuptoseveralhundredm3ofmedia,costingupto300/m3

frycostshigherthananticipated

6.4 Planned vactualsalespriceAlthoughonesiteachievedandonesiteexceededtheirpredictedsalesprices,manyofthesiteshad

beenunabletoobtaintheirplannedsalesprice.Onesiteplannedasalespriceof16/Kg,revisedthis

downto6/Kg,butthebestpriceachievedwas3.20/Kg,withafinalaverageof2.40/Kg.Prices

quotedwereclearlyhigherforpremiummarinespeciessuchasturbotandbass.Sitesproducing

lowervaluespeciessuchastilapiaorcatfishindicatedthatsalesat3.00/Kgwouldprovideaviable

business,butmanywerestrugglingtoachieve2.20 2.80/Kg. Thepressuresandproblemscaused

bysupermarketswerementioned,e.g.promotionalofferswhichreducedpricesthefarmers

receivedandcausedashorttermincreaseinsales.Severalsiteshadmanagedtoobtainhigher

pricesbydeliveringtolivefishmarkets.

6.5 Productioncosts,paybackandaccountingrateofreturnAccuratefiguresforfinancialappraisalweredifficulttoobtainwithmanyfarmerseitherunwillingor

unabletosupplythese.Insomecasesfigureswerewithaccountants.However,threesitesnolonger

inoperationquotedproductioncostsofbetween1.50/Kgfortilapiaand7.70/Kgforturbot.

Paybackistheperiodtakenforaprojecttorecoveritsoriginalcostinfuturecashflows.Twosites

mentionedthattheyhadexpectedtoachievethiswithintwoyearsbutapaybackperiodof5years

wasmorerealistic.Onesite,currentlybetweendevelopmentphases,wasconcernedaboutthe



30/51

lengthoftimebeforeareturnwasachieved(interpretedbyinterviewerstomeanachieving

payback).

Accountingrateofreturnmeasuresthepercentagereturntheprojectachievesoveritslifeinterms

ofprofitability.Twositesthatarenolongeroperatingdidprovidecrudefiguresonrateofreturn

statingthatitwasjust2550%ofthelevelspromisedbythesystemsalesperson/installer.

Thelargescale,operatingsiteswithbetterfinancialmanagementdidnotquotefigures,butwere

optimisticandfirmlybelievedinthefutureofRAS. OnedidindicatethatthecurrentRASsystems

didneedtoevolvefurtherforanother10yearstoassurefinancialsustainability.Oneinterviewee

gavethemainreasonhesoldupasteethingproblemsthatwentontoolongsoheendedupwith

halftheexpectedsalesanddoublethecosts.

6.6 LiteraturereviewfindingsTheUniversityofStirling,hasexaminedthepotentialfordevelopmentofwarmwaterproduction

systemsasadiversificationrouteforUKagriculturalfarmers31

.Onepartoftheprogrammelookedat

theeconomics,withsensitivityscenarios.Usingtypicalfarmgatepricesfortilapiaof3.00,3.70

and4.50/Kg,salespriceemergedasthemostcriticalsensitivityitem. Manyofthetilapiafarmers

interviewed

in

the

current

study

had

struggled

to

achieve

even

the

lowest

modelled

sale

price.

TheStirlingresearchshowedthatcontinuousproductionwasmoreprofitablethanbatch

production:forprofitablebatchproduction,thesmallestunitswouldneedtoachieveasalespriceof

3.20/Kgtobringthemtoprofitability,comparedto2.65/Kgforcontinuousproduction. The

analysisshowedthatprofitabilityiscloselyrelatedtoproductionscale,butalsoindicatedthatrisk

increaseswiththescaleofoperation.Theresearchalsopointedoutconsiderablescopefor

increasingprofitsbyincreasingenergyefficiencyandintegratingcombinedelectricityandheat

biomasssystems.

The(somewhatcrude)industrysurveyinformationsummarisedaboveandtheStirlingprojectdonot

supportstrongfinancialsustainabilityoffreshwaterRASinEngland. However,thesituationcould

changemarkedlyifsalespricesareincreasedbyexternaldrivers.Thepressureonwildfishstocksis

mountingasglobaldemandforseafoodproductsgrows32

,humanpopulationsincrease33

,andper

31http://www.tilapiascotland.org/relu32http://www.fao.org/docrep/007/y5767e/y5767e0d.htm

33http://www.statistics.gov.uk/cci/nugget.asp?id=1352



31/51

capitademandincreasesduetotherecentmessageforincreasedfishconsumption34

.Therehave

alreadybeenpricesrises35

andshortages36

,whichcouldleadtohigherfarmgateprices.Thepromise

offeredbyRASisfurtherillustratedbyinvestmentinresearchanddevelopment,e.g.:

ArecentfeasibilitystudyofclosedcontainmentoptionsfortheBritishColumbiaaquaculture

industry37

comparedopencagestoRAS.Overall,thestudyfoundasignificantadvantagefor

cagesintermsofpretaxincome.AlthoughRAStechnologywasmarginallyviablefinancially,it

representedahigherlevelofrisk.RASbenefittedfrommoreefficientbiologicalfeedconversion

ratio(FCR),temperaturestability,andimprovedenvironmentalcontrol,butthiswasatthecost

ofhigherexpenditureoncapital,energyandlabourwhichimpactedoverallprofitability.

Nevertheless,aswithmostemergingtechnologies,oncewiderRASuptakeisachieved,capital

andoperatingcostsmaygodown.Ifclosedcontainmenttechnologiesachieveacriticalmassof

production,operatorsmaybenefitfromeconomiesofscaleforacquiringcapitalitems,and

increasingexpertisecouldreduceoperatingcosts38

.

InManitoba,Canada,amodelinlandrecirculationtroutfarmisbeingdeveloped,with

encouragementfromtheauthorities,fromwhichdataisbeingrecorded.

InNorway,NOFIMAhavejustopenedastateoftheartrecirculationaquacultureresearch

facilityandacknowledgethatrecirculationwillbeimplementedwithintheindustryinthenear

future39

.

6.7 OverallassessmentoffinancialsustainabilityHistorically,thefinancialviabilityofrecirculationaquaculturehasnotbeengood:itisadeveloping

sectorthathasmademanymistakes. Currentsalespricesformanyspeciesmakethereturnon

investmentmarginal.Howeverifcapitalcostsreduce,andtechnologyandenergyefficiencyreduces

runningcosts,theoutlookmayimprove.Furthermore,salespricesmayincrease:consumersare

becomingincreasinglymoreadventurouswiththeireatinghabitsandRASofferanopportunityto

growadiverserangeofspeciesclosetomarkets.Potentialinvestorsshouldthereforeproceedwith

cautionandpayparticularattentiontominimisinginputcostsanddevelopprudentbusinessplans

thatreflectthemarket.

34http://www.food.gov.uk/news/newsarchive/2006/mar/oilyfish

35http://www.talkingretail.com/news/industrynews/fishpricestoriseby5asdemandincreasesandinflationbites

36http://www.enn.com/top_stories/article/41773

37http://www.dfompo.gc.ca/aquaculture/libbib/nasapiinpasa/BCaquacultureCBeng.htm

38http://www.dfompo.gc.ca/aquaculture/libbib/nasapiinpasa/BCaquacultureCBeng.htm#executive39http://www.fishnewseu.com/index.php?option=com_content&view=article&id=4838:berghansenopensrecirculationresearch

centre&catid=46:world&Itemid=56



32/51

7 Factors leading to historical failure ofsome RAS

7.1 Top10criticalfactorsDuringthevisits,the14intervieweeswereaskedtopickandranktheirtop10keyfactors

contributingtothesuccess(orfailure)ofawarmwaterRAStablefishfarm.Rankingswere

convertedtoscores(highscore=importantfactor)whichweresummedfordisplay(Figure5).

Government support

Lack of automation

Veterinary support

CertificationTechnical stock issues (e.g. maturation)

Survival rates

Added value/own processing

Lack of funding

Supplier support

Staff costs

Husbandry difficulties

Food costs

Disease

System failure

Scale of site

Food conversion rates

Supermarkets

Paperwork

Diet / nutrition

Product quality

Access to markets

Lack of backups (alarms)

Competition from cheap imports

Growth rate

Staff aquaculture knowledge

Water quality issues

Owner / manager experience

Planning

Sales price achieved

Choice of species

Demand for productElectricity/gas/heating costs

Fingerling supply (& price)

Marketing

System design

Rank score

Figure5: CriticalfactorsforthesuccessorfailureofwarmwaterRAS,asscoredbyRASindustry

interviewees.

Technical(systemdesign)andsomeeconomicfactors(marketing,energycosts,demandfor

product),alongwithfingerlingavailability/price,emergedasthekeyissues.Staffknowledgeand



33/51

biologicalfactorsappeartobeconsideredaslesscritical;regulatoryandcertificationissuesappear

tobeofminorimportance.

7.2 AdditionalfactorscontributingtofailureOtherkeyissuescontributingtofailedoperationswereidentifiedduringinterviews.Theseare

categorisedinTable4.

Table4:OtherkeyissuesidentifiedduringinterviewsascontributingtofailedRASoperations.

Reasonsforclosingtheoperation Sitespecificproblems

Operationaldesignissues Inappropriatewatersupply

Cashflowanddebts Restrictedaccesstofacilities

Salesvolumes Sitetoosmall

Marketprices Wastetreatmentanddrainageproblems Overheads Distancefrommarkets

Systemspecificproblems Mistakesmade

Modificationstooriginalbuild Onlyconsultingonesupplier/designer

Inadequatefiltrationsystem Notpilotingbeforescaleup

Qualityofsystembuild Unrealisticexpectations

Pipeworkandflowdesign Notenoughattentiontodetail

Lackofautomatedsystemsforharvesting

andmortalityremovals

Inputsandcoststoohigh

Inflexibility

of

system

Not

checking

access

to

markets

Ofthemajorreasonsidentified,thetechnicalandeconomicreasons(costs)forfailurehavebeen

discussedabove.Otherissuesthatmeritdiscussionrelatetomarketsandeconomiesofscale.

7.3 MarketsFishfarmersnaturallyfocusonproducingfishandsalesisrecognisedasanareawheretheyoften

droptheball40

.Manysitesappearednottohaveunderstoodthemarketatthebeginningofthe

operationandhadconsequentlychangedorstruggledtofindoutlets. Fewoperationsappearedto

haveinvestedeffortinthefourPs(Product,Price,PlacementandPromotion)41

.

Intendedmarketsvariedbetweensites,largelyduetodifferencesinthescaleofoperation.

Smallersiteswereunabletosupplysupermarketswiththevolumesdemanded,sofocussedon

localorethniclivemarkets. Sitesthattargetedethnicmarketshadgoodinitialuptake,butthen

40http://aquaculture.ext.wvu.edu/r/download/59173

41http://www.eldis.org/go/topics/resourceguides/healthsystems/keyissues/marketdevelopmentapproaches/tools/4ps

http://aquaculture.ext.wvu.edu/r/download/59173http://aquaculture.ext.wvu.edu/r/download/59173http://aquaculture.ext.wvu.edu/r/download/59173


34/51

hitaceiling.Severalfoundtheprocessofdistributiontolocalorpremiummarketsonerousand

endedupsupplyingwholesalers,processorsorsupermarketsasalastresort.

Manysitesciteddifficultiesindealingwithlargersupermarketssuchasbeingunabletosupply

whentheydemanded,andcopingwithpromotions. However,contractshadbeensetupto

facilitatetwowaycommunicationandunderstandingoftheproblems supplybythefarm,and

thesupermarketsneedforpromotions.

Otherissueswithmarketsthatemergedduringinterviewsincluded:

Breakingin Someofthelargertilapiaproducersfeltthatthemarketwasthere,butwasdifficult

toaccess,possiblybecausetheydidnothaveadiversebasketofproductstooffer.

Dependence Afewsiteswerereliantonasingleoutletfortheirproduct,andwereleft

flounderingifthisavenueclosed.

Productquality Onesitereleasedfishontothemarketbeforethedepurationsystemwas

operationalandasaresultacquiredareputationfortaintedfishthatproveddifficulttoshift.

CompetitionThelowcostofimportsinrelationtodomesticproductionwasraisedseveral

times.

Twositesdidrecognisetheimportanceofmarketingtheirproducts:

Onesiteallocated10%ofproductioncoststomarketingand,asaresult,hadalwaysachievedor

exceededtheirfarmgateprices.

Anotherofthelargersiteshadadedicatedsalesmanagertokeepcustomershappywhichwas

perceivedasakeytosuccess.

7.4 Addingvalue:processing,accreditationschemesandbrandingNearlyalloperatingsitesdidtheminimumamountofprocessingtheysoldwholefishwith

negligibleamountsofdescalingandpacking.Afewsitesstatedthattheydidnotwanttoget

involvedinprocessing.Incontrast,severalsiteswerecontemplatingprocessing,withonegroup

consideringasharedfacility.

Approximatelyhalfofthesitesvisitedhadneverbeeninvolvedinanaccreditationscheme.Twoof

thelargeroneshadjoinedupwiththeQualityTroutUK(QTUK)scheme,andothersiteswere

consideringjoining.



35/51

Somesiteswereconsideringdevelopingtheirown,orlocal(group)brands.Severaltilapiafarmers

consideredthathighlightingtheirproductsaslocally/regionallyproduced(e.g.bredinNorfolk,

raisedinSuffolk)wouldbeamarketableattribute.Severalfarmerswerekeentoconveythe

sustainabilityattributesoftheirproductsandmakethemostofgreencredentialsthrougheco

labelling42

.However,thiswasnotyetoccurring,becauseeithertheywereunclearofhowtogo

aboutit,oritwasbeingleftassomethingforthefuture.

7.5 EconomiesofscaleWhilstthisdidnotrankhighlyasatoptenfactor,thevastmajorityofsitessuggestedthat

economiesofscalewereveryimportantintermsoffinancialsustainabilityandcriticalinsupplying

supermarketchains.Afewnonoperationalsitesexpressedtheopinionthatiftheyhadpilotedthe

projectorstartedsmallthiswouldhavereducedthecostlymistakesmadelater.Twofarmers

expressedtheopinionthatbeingsmallhadreducedtheirlossestomostlytheirownlabour,

althoughoneofthesesitesdidqualifythisbysayingthathecouldhavehadaviableoperationif

productionhadincreasedfrom10to20tonnesp.a..

42MungkungRT,deHaesHAU,CliftR(2006).PotentialandlimitationsofLifeCycleAssessmentinsettingecolabellingcriteria:acasestudy

ofThaishrimpaquacultureproduct.IntJLCA11,5559.



36/51

8 Sustainability issues relating to RAS

TheEUAquaculturestrategycallsfordevelopmentofasustainableindustry.Awidelyused

definition

of

sustainable

is

developmentwhich

meets

the

needs

of

the

present

without

compromisingtheabilityoffuturegenerationstomeettheirownneeds43.Sustainabilityisanidealaimedatensuringsatisfactoryenvironmental,social,andeconomicconditions,andcanbe

envisagedasaddressingfourobjectives44

:

effectiveprotectionoftheenvironment

prudentuseofnaturalresources

socialprogresswhichrecognisestheneedsofeveryone

maintenanceofhighandstablelevelsofeconomicgrowthandemployment.

EconomicissuesrelatedtoRASarediscussedabove;herewediscussenvironmentalprotection,

naturalresourceuse,socialissuesandemploymentinrelationtoRAS.

Nearlyallofthefarmsvisitedwereawareoftheenvironmentalandresourceusecredentialsoftheir

products,e.g.locallyproducedandlowfoodmiles,rearedonlowfishmealdiets,lowwaterusage,

efficientuseofspace.However,farmersoftenstruggledtodiscusssocialsustainabilityissues,but

didsowhenpromptedbyinterviewerswithexamples.

8.1 EnvironmentalprotectionRASfarmsscorestronglyintermsofenvironmentalprotection,largelyduetotheirinherent

features.

Finfishaquacultureisoftencriticisedovertheissueofescapeesandtheirimpactsonlocalstocks

thoughcompetition,interbreedinganddilutionoflocalgenepools.Duetotheircloseddesign,

typicallocationremotefromnaturalwaterbodiesandcultureoftropicalspecies,noneoftheRAS

siteshadexperiencedanyproblemswithescapees.

Openfinfishfarmsareoftenperceivedtoactasreservoirsofpathogensthatinfectwildstocks.

Again,thecloseddesign,locationawayfromnaturalwaterbodies,treatmentofeffluentandculture

oftropicalspecies,negatethisissuefortheRASfarmsvisited.

43http://archive.defra.gov.uk/sustainable/government/publications/ukstrategy/documents/NewGlossary.pdf

44http://archive.defra.gov.uk/wildlifepets/zoos/documents/zoo handbook/3.pdf



37/51

ContainmentofwarmwaterRASwithinbuildingsalsoeliminatesinteractionswithwildpredators,

withnositereportingpredatorproblems.Twositesdidmentionaneedforpestcontrolandused

professionalcontractorstocontrolratsaroundthefarm.

Openaquaculturesystemsmaynecessitatemodificationstonaturalwaterbodiesandchangesin

flow,duetoconstructionofchannelsforabstractionanddischarge.Again,RASavoidsuchimpacts.

Inopenaquaculturesystems,dischargeofveterinaryproductscanbeaconcern.Again,thelocation

ofRASfarmsawayfromnaturalwaterbodiescoupledwithretentionofwaterwithinthesystem

eliminatesthispotentialissue.Furthermore,RASaregenerallydesignedtohavehighbiosecurity

beingwithinabuilding,drawingwaterfromsourceswithoutfishpathogensorsterilisingifdrawn

fromnaturalwaterbodies.Alargeproportionofthesitesvisitedhadthereforenotusedany

veterinaryproducts.

Inopen,flowthroughfishfarms,thereisdischargeofeffluentcontainingsuspendedsolids,

dissolvedinorganicanddissolvedorganicwastesintonaturalwaterbodieswhichcanreducethe

qualityofthelocalenvironment.Again,thelocationofRASfarmsawayfromnaturalwaterbodies

coupledwithtreatmentofwasteswithinthesystemeliminatesthisissue. RASdoneedtodischarge

a

small

percentage

of

the

recirculating

water

(

10%

/

day)

to

prevent

excessive

build

up

of

nitrates

andothercompounds.Thiseffluentcouldhavepotentialeutrophicationimpacts,butRAStendto

dischargetosewers,settlementtanks,ditches,orconstructedwetlandsratherthannaturalwater

bodies.Constructedwetlandsprovideanaturalmeansofcleaningeffluent,andcanprovideanew

habitatforwildlife.

RASsystemscaptureandconcentratesuspendedsolidswasteswhichrequiredisposal.SomeRAS

farmsusewastedisposalsystemsalreadyinplaceaspartoftheiragriculturalfarms;somespread

theirsolidwasteontofields(representingreuseasfertilizer);somehavewastetakenawayaspera

septictank;othershavehadthewasteclassifiedasindustrialwasteandhavetopayforaspecial

licenceanddisposal.

OneenvironmentalweaknessofRASistheirhighenergyuse(seebelow)whichcontributestoglobal

warmingduetotheburningoffossilfuels.RAStypicallyhavedoublethecarbonfootprintofflow

throughsystems45

. ThekeytoreducingcarbonfootprintofRASistoswitchtorenewableenergy

45SeeEllisetal.(2011)InitialinvestigationofthesustainabilityofEnglishaquaculture.CefascontractC3743reporttoDefra



38/51

sources.Everysitevisitedhadinvestigatedorexperimentedwithalternativeenergysources,i.e.

woodchipburners,solarpanels/photovoltaics,windturbines,biogasplants,anaerobicdigesters,

groundsourceheatpumps, anduseofwasteheatfromanicerink.Althoughreuseofwasteheat

fromthirdpartysourcesmaybegreen,asymmetriesbetweenthecooperatingbusinesseshave

typicallymadepreviousattemptsunsuccessful46

.

OnepotentialadvantageofgrowingtilapiaintheUKoverimportofforeignproductionisthatthe

associatedfoodmilesaremarkedlyless.However,simplyfocussingonfoodmilestravelledbythe

finalproductignoresthemodeofproduction,modeoftransport,andtransportofinputssuchas

feedsandfry.OnestudyassessedtheglobalwarmingimpactsofcagetilapiaproductioninIndonesia

andtransporttoEurope47

.Inthecontextofthefullproductioncycle,transportationimpactswere

negligible,astransportoffrozenfilletsinoceanfreightedcontainersisefficient.ThismeansthatUK

productioninRAScontributedmoretoglobalwarmingthanproductioninIndonesiacombinedwith

importation48

.Nevertheless,RASproductionintheUKwasassociatedwithlesseutrophication.

FurthermoreaseparatestudyhasindicatedthatproductionofAfricancatfishinDutchRASresultsin

lowercarbondioxideemissionsthanPangasiuscatfishfarmedinpondsintheMekongDelta49alsotakingintoaccounttransportationcosts.

8.2

Natural

resource

use

RASsystemsareinamixedpositionintermsofresourceusage.Asintensivesystems,theydo

requireinputofnaturalresources,sotheemphasismustbeonmaximisingefficiency.

RASfarmsrepresentanefficientuseofland. Comparativeproductionfiguresfortilapiaare1340

tonnes/ha/yearforRASversus17.4tonnes/ha/yearforaconventionaltilapiafarm50

.

WateruseinRASisevidentlyefficientincomparisontoopen/flowthroughaquaculture:

comparativedataare0.5m3

/KgRASv31m3/Kgtilapiaproductioninaconventionalintensive

farm51

.RASalsocomparefavourablytoterrestrialanimalproductssuchaspigsandeggs52

.

46LittleDC,MurrayFJ,AzimE,LeschenW,BoydK,WattersonA,YoungJA(2008).OptionsforproducingawarmwaterfishintheUK:

limitstogreengrowth.TrendsinfoodScience&Technology19,255264.47PelletierN,TyedmersP(2010).LifecycleassessmentoffrozentilapiafilletsfromIndonesianlakebasedandpondbasedintensive

aquaculturesystems.JIndustrialEcology14,467481.48SeeEllisetal.(2011)op.cit.

49PoelmanM,SchneiderO,Abstractat8

thInternationalConferenceonRecirculatingAquaculture.

50Sustainablefinfishaquacultureworkshop.FinfishNews9,422;http://www.slideshare.net/Cefas/largescaleintensiverecirculation

systemsandtheirpotentialdevelopmentwithinengland237388151http://www.slideshare.net/Cefas/largescaleintensiverecirculationsystemsandtheirpotentialdevelopmentwithinengland2373881

52http://www.oecd.org/dataoecd/19/21/45032957.pdf



39/51

However,simplecomparisonsofvolumeofwaterusedinproductionaretoosimplistic53

.Themetric

forwateruse m3/Kgproduction doesnotaccountfortheimpactofabstractiononthesourceof

thewater(i.e.mains,groundwater,river,lake,sea)whichwillberelativetoitsavailability.

Furthermore,open/flowthroughaquacultureisanonconsumptiveuseofwaterasitispromptly

returnedtothesamewaterbodyfromwhichitwasabstracted;incontrast,RAScouldbeconsidered

asaconsumptiveuserofwater,althoughsomedischargedwaterwillfinditswaybackintothe

watertableviasewageworksorspreadingontheland.

RASfarmshaveahighenergyuseastheyrelyontechnologytomovewaterandmaintainitsquality.

EnergyuseacrosstheproductioncyclehasbeenexaminedinanumberofstudiesandRASfarms

typicallyrequire2to3timesmoreenergythanflowthrough/openaquacultures

Date post:	03-Apr-2018
Category:	Documents
Upload:	lte002
View:	228 times
Download:	1 times

Fish Farm Fcf-recirculation

Documents