Good Aquaculture Practices to Reduce the Use of Chemotherapeutic Agents, Minimize Bacterial Resistance, and Control Product Quality

StanleySERFLING＊

Abstract:Asignificantchallengeto theexpansionofaquacultureproduction iscontrollingtheoutbreakofdisease.Manyfarmerswhoexperiencethepotential lossofstockfromdiseasemaychoose tousechemotherapeuticagents tominimize their loss. It isgenerallyunderstood thatadiseaseinaquacultureisacombinationofthehealthoftheanimal,theconditionoftheenvironmentandthepresenceofapathogen.Fromthisconceptthereareanumberofprecautionarymeasuresthat farmersmaypractice tominimizediseaseoutbreaks.TheprinciplesofHazardAnalysisCriticalControlPoint(HACCP)maybeusefulriskmanagementtoolstoreducepathogens,animalstressandtheneedforchemotherapeuticagentstocontroldiseaseoutbreaksonthefarm.

Key Words:goodaquaculturepractices,chemotherapeuticagents,bacterialresistance,foodsafety

Introduction

　As the global demand for seafood increases,the trend towards high density aquaculturesystems grows. These systems referred to as“intensiveaquaculture” increasinglyrelyon inputsof oxygen, formulated feed, and the applicationof agrochemicals, andantibiotics.Thismethodofculturemayalsocreatestressfulconditions for theanimalsand increasetheriskofbacterial infectionsand therefore theuseofchemotherapeuticagents(Sapkotaet al., 2008).　ShrimpisthesinglemostpopulartypeofseafoodintheUnitedStatesandover90percentofshrimpproducts are farmraisedand importedprimarilyfrom Southeast Asian countries. The primaryhazards associatedwith aquaculture shrimp arecontamination frompathogensand residues fromunapproveddrugs.Theoriginsforthesehazardsarefromproductionfarmsandcanremaininorontheproductthroughoutthenormalcleaning,rinsingandpackagingprocess. 　Between2001and2003 theU.S.FoodandDrugAdministration analyzed 1,234 samples from103shrimpaquaculturefarmsrepresentingsixcountries

for fecalcoliforms,Escherichia coli,andSalmonella.AsignificantrelationshipwasfoundbetweenthelognumberoffecalbacteriaandtheprobabilitythatanygivensamplewouldcontainSalmonella.ThestudyconcludedtheoccurrenceofSalmonellabacteria inshrimpfromaquaculturefarmsisdirectlyrelatedtotheconcentrationoffecalbacteriainthesourceandproductionpondwater(Koonseet al., 2005). 　The importance of chemical and antimicrobialcompounds in theprotectionof animalshasbeenacknowledged,but thenegative impactanduseoftheseagentsinanimalsraisedforfoodisaconcern.

2015年 1 月30日受理（ReceivedonJanuary30, 2015）＊ U.S.FoodandDrugAdministration,OfficeofFoodSafety,CollegePark,MD20740 E-mail:stanley.serfling@fda.hhs.gov

Fig. 1.

水研センター研報，第40号，83－88，平成27年Bull.Fish.Res.Agen.No. 40，83－88，2015

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Thedetectionofcertainbannedchemotherapeuticagentsinfishandcrustaceansininternationaltradeduring 2001-2002 led to greater attention aboutthepotentialhealthrisks fromfarmraisedseafoodproducts(Iddya, 2012).

Good Aquaculture Practices

　Goodaquaculturepractices(GAqP)canbedefinedinmanyways. Ingeneral it isbasedonpreventivepractices that aredevelopedand implemented tomeettheneedsofthespecies,culturemethodsandlocal environmental conditions.Whenaquacultureproducers take time to identifypotential risks totheiroperationand implementcontrols tomanagetherisk,thenthepotentialfordiseaseandtheuseofchemotherapeuticagentsisminimized.　The Hazard Analysis Critical Control Point(HACCP)principles canbeused as apreventiveriskmanagementsystemtocontroltheintroductionofpathogensataquaculture facilities.TheHACCPapproach is based onprevention and requires ahazardanalysis that identifies apotential hazardin the system and then aCritical Limit,with amaximumandorminimumpoint, is set for eachcomponent of the system.Whenmonitoring theaquaculturesystemandacritical limithasbeen inviolation, thenacorrectiveaction is takentobringthe systemback into compliance (Jahncke et al., 2002). 　TheseHACCPprinciplesprovideastepbystepapproach to identifyandcontrolhazards found intheenvironmentandproductionprocess forbothfreshwaterandmarineaquaculture.The following

arethesevenbasicprincipleswithanexample:

　1. Hazard and Risk Analysis: Collect andevaluate informationonhazardsassociatedwith the product under consideration todecide the likelihoodof theoccurrenceandthe severity of the occurrence. To helpidentifyapotentialhazarda farmer shouldconstructaflowdiagramwithalloftheinputsto the farmand thenevaluateacontrol foreachpotentialhazard.

　　　－ SeeFig. 3forashrimpfarmflowdiagram.

　2. IdentifyCriticalControlPoint(CCP):Thisstepisessential topreventoreliminateahazardorreduceittoanacceptablelevel.

　　　－ Forexampleashrimpfarmermaychoosecriticalwater quality parameters suchasminimumandmaximumoxygenandtemperaturelevels.

　3. EstablishCriticalLimits:Amaximumand/orminimumvaluetowhichaphysical,chemicalor biological hazardmust be controlled toprevent,eliminateorreducetoanacceptableleveltheoccurrenceofahazard.

　　　－ For example a critical limit could bestockingdensityatahatchery tankandtheratiooflivefeedtoanimal.

　4. EstablishMonitoringProcedures:Monitoringis aprocess that theaquacultureoperationrelies on tomaintain control of aCriticalControl Point . Accurate monitoring isimportanttohelpdeterminewhenaCCPhasdeviated fromthedesiredrange.Failure toproperlyuseandmonitorchemotherapeuticagentsmayresult indetectable residues inthetissueofaquaculturedproducts.

　　　－ Forexample,monitoringaspecificwaterquality parameter every day or morefrequentlydependingon theproductionsystem.

　5. EstablishCorrectiveActions:The farmershould identifyprocedures to followwhenadeviation fromtheacceptablerangeoccurs.Fig. 2.

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Thefarmerwillimplementacorrectiveactionplanafter thedeviationhasbeen identifiedandpreparea longtermsolutionassoonaspossible.

　　　－ For example if a farmer has identifiedthefeedsupplyforthehatcherydoesnotconformtorequiredstandard,theproductis rejected and the farmer contacts analternatefeedsupplierfornewfeed.

　6. Establish Verification Procedures: Thisprocedure helps to determine the validityof theoperationandverify that the farm isoperatingaccordingtoplan.

　　　－ Forexamplethefarmermayreviewdailywater quality parameter sand feeding

records to determine if the productionsystemismeetingexpectedoutput.

　7. EstablishRecordKeepingProcedures:Thefinal step is todocumentallprevioussteps,from theEvaluation ofHazards and flowdiagram, the identificationofCriticalControlPointsandCriticalLimits,andanyCorrectiveActionstaken,andallVerificationProcedures.

　　　－ Recordsshouldbemade forall identifiedCriticalControlPointsandbeaccessibletostaffinpaperorelectronicformat.

　Fig. 3 is an example of an operational flowdiagramforan integratedshrimpfarmwithbroodstock,hatchery,nursery,andgrowoutproduction.

Fig. 3.Processflowdiagramofanintegratedshrimpfarmwithhatchery.

CCP – Critical Control Point SOP – Standard Operating Procedure

Broodstock Maturation - Reproduction

Live food Production

Larval Culture

Grow-out ponds

Pond Side Harvest

Water quality (CCP) Fresh/prepared feed (CCP)Vector control (SOP) Equipment (SOP)

Water quality (CCP) Live food source (CCP) Vector control (SOP) Equipment (SOP)

Water quality (CCP) Fresh/frozen food (CCP) Vector control (SOP) Equipment (SOP)

Stocking Density (CCP) Prepared feed (CCP) Vector control (SOP) Equipment (SOP)

Water quality/ice (CCP) Equipment (SOP) Trained Staff (SOP) Farm conditions (SOP)

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Preventive Measures

　Astandardoperatingprocedure (SOP)manual isanimportantdocumentthefarmershouldassemble.Thisshouldincludefacilitydesignandflowdiagram,generalhusbandryprocedures foreachstep intheproductionprocess, restrictedaccessareas,wastemanagement, pest control and staff rules. GoodAquaculturePracticesmay also includewelfareof theanimals, environmental integrityandsocialresponsibility. 　There are a number of biological, chemicalandphysicalprecautionarymeasures that canbeundertaken.The followingareexamplesofhowtoapplythesepracticesonthefarm.Biological : Includes measures to prevent ortreat infect ions such as the proper use ofchemotherapeuticagentsor theuseofvaccinesaswellasmanagementpracticestopreventthespread

of pathogens by isolating and testing incomingseedstock. Inaddition,providingcleanwaterandsanitaryfacilities forstaffandproperfarmsecurityhelptocontrolthespreadofpathogensfromhumansandanimals. Chemical: Includes measures that are used toprevent the introductionofpathogensorvectorsbytreatingmaterialsbeforetheyenterthe facility.Forexample,chlorinationorozonecanbeusedtotreatincomingwater,andiodineandchlorinecanbeusedto treatotherpotentialvectorssuchas tools,footwearandclothing. Physical: Includesbarriers thatmaybeuseful topreventvectors fromcontaminating a farm site.Physicalbarrierscanbestress reducingpracticeslikeproper stockingdensities, optimal levels fordissolved oxygen and temperatures, andproperfeedingpractices.

Table 1.Thefollowinghazardanalysisforanintensivemarineshrimpfarm.

Table 1. The following hazard analysis for an intensive marine shrimp farm.

Identify Potential Hazard

Is the Hazard Significant

Justification Preventive Measures CCP

Seed stock Yes Shrimp larvae may contain detectable pathogen

SPF certification for each receipt. Quarantine procedures and test periodically (CCP)

Yes

Water Source Yes Potential pathogens

Provide pre-treatment to ensure water supply is safe (CCP)

Yes

Feed Source Yes May result in and poor production

Certificate from feed supplier to ensure standard (CCP)

Yes

Stocking Density Yes Important to optimize production

Controlled by Standard Operating Procedure (SOP)

Yes and No

Effluent or Recirculated Water

Yes Effluent may contain pathogens

Controlled by Standard Operating Procedure (SOP)

Yes and No

Animal and Human Vectors

Yes May transfer contaminants and pathogens

Controlled by Standard Operating Procedure (SOP)

No

Farm Equipment and Sanitation

Yes Equipment may become contaminated with pathogens

Controlled by Standard Operating Procedure (SOP)

No

SPF – Specific Pathogen Free CCP – Critical Control Point SOP – Standard Operating Procedure

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Conclusion

　GoodAquaculturePracticesmaybeapplied tomanydifferentkindsof aquaculture systems inavarietyofmanagementstrategies.Thekeyelementscanbe summarized as reliable sources of stock,gooddiagnosticanddetectionmethods fordisease,disinfectionanderadicationofpathogensandbestmanagementpractices.HACCPprinciplesprovidea logical stepby step approach to help preventpathogencontaminationandtheoutbreakofdiseaseonthefarmsite.Thismanagementapproachallowsthe farmer to choose themost importantprocesscontrol stepsand thenchooseappropriatecriticalcontrolpointsandcontrolmeasurestominimizeriskto theanimalsand the farmoperationand insurethatchemotherapeuticagentsifneededwillbeusedwisely.

References

JahnckeM.L.,BrowdyC.L.,SchwarzM.H.,SilvaJ.L.,SmithD.C.,andStokesA.D., 2002:Riskmanagement,diseaseprevention, andHACCPprinciples:Applicationofhazardanalysiscriticalcontrol point (HACCP) principles as a riskmanagement tool tocontrolviralpathogensatshrimpaquaculture facilities.NOAAOfficeofSeaGrant,VirginiaGraduateMarineScienceConsortiumandtheVirginiaSeaGrantCollegeProgram,PublicationVSG-02-10,Pages1-33.

Karunasagar I., 2012: Public health and tradeimpact of antimicrobial use in aquaculture,in “Improving biosecurity through prudentand responsible use of veterinarymedicinesin aquatic food production” (ed byBondad-ReantasoM.G.,Arthur J.R. andSubasingheR.P.)FAOFisheriesandAquacultureTechnicalPaperNo. 547.Rome,FAO,pp. 1-9.

KoonseB.,BurkhardtW.,ChirtelS.,andHoskinsG., 2005:Foodsafetyandaquaculture,controllingrisk,coliformbacteria:SalmonellaandSanitaryQualityofAquacultureShrimp. J. Food Prot., 68,No12, 2527-2532.

SapkotaA., SapkotaA.,KucharskiM.,Burke J.,McKenszieS.,WalkerP., LawrenceR., 2008:Aquaculture practices and potential health

risks:Currentknowledgeand futurepriorities.Environ. Int. J., 34, 1215-1226.

Annotated Bibliography

JahnckeM.L.,BrowdyC.L.,SchwarzM.H.,SegarsA.,SilvaJ.L.,SmithD.C.,StokesA.D., 2002:Risk management, disease prevention, andHACCP principles: Application of hazardanalysis cr i t ica l control point (HACCP)principlesasariskmanagementtooltocontrolviralpathogensatshrimpaquaculturefacilities.NOAAOfficeofSeaGrant,VirginiaGraduateMarineScienceConsortiumand theVirginiaSeaGrantCollegeProgram,PublicationVSG-02-10,Pages1-33.

　TheauthorsidentifyhowtheprinciplesofHACCP(HazardAnalysisCriticalControlPoint)canbeusedasapreventiveriskmanagementsystemtocontrolthe introductionofpathogensand theoutbreakofdiseaseinshrimpaquaculturefacilities.TheHACCPapproachrequiresahazardanalysis that identifiesapotentialhazardinthesystemandthenaCriticalLimitwithamaximumandorminimumpointissetforeachcomponentofthesystem.Whenmonitoringtheaquaculturesystemandacriticallimithasbeeninviolation,thenacorrectiveactionistakentobringthesystembackintocompliance.　Todevelopaneffectivebiosecurityprogramfishandshrimp farmersshould followtheseprinciplesbasedon seafoodHACCP: 1)PerformSystematicHazardAnalysis, 2)DetermineCritical ControlPoints, 3)EstablishCriticalLimits, 4)DetermineAppropriate Corrective Actions, 5) EstablishMonitoringProcedures, 6)EstablishVerificationProcedures, 7)EstablishRecordKeepingSystems.

Karunasagar I., 2012: Public health and tradeimpact of antimicrobial use in aquaculture,in “Improving biosecurity through prudentand responsible use of veterinarymedicinesin aquatic food production” (ed byBondad-Reantaso,M.G.,Arthur J.R. andSubasingheR.P.)FAOFisheriesandAquacultureTechnicalPaperNo. 547.Rome,FAO,pp. 1-9.

　The Food and Agriculture Organization ofthe United Nations (FAO), the World Health

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Organization (WHO) and theWorldOrganizationforAnimalHealth(OIE)organizedconsultationsandtechnicalmeetingstoreviewtheglobalseafoodtradeandtheuseofantimicrobialagents inaquacultureanddeveloprecommendations.Theauthoroutlineshowdetectionofcertainbannedantibiotics in fishandcrustaceans in internationaltradeduring2001-2002 leadtogreaterattentiononthepublichealthrisks owing to theuseof antimicrobial agents inaquaculture.Most fish importing countries adopta zero tolerance approach regarding residues ofantimicrobials that are banned for use in foodanimals. In suchcases, residue levels thatattractregulatoryactionarebasedonanalyticalcapabilityratherthantoxicologyoftheresidues.

KoonseB.,BurkhardtW.,ChirtelS.,andHoskinsG., 2005:Foodsafetyandaquaculture,controllingrisk,coliformbacteria:SalmonellaandSanitaryQualityofAquacultureShrimp. J. Food Prot., 68,No12, 2527-2532.

　The authors examined the prevalence ofSalmonella and coliform bacteria on shrimpaquaculture farms in severalAsian countries todevelopguidelines orpreventativemeasures forreducing Salmonella and fecal contamination onproductsharvested fromthese farms.Asignificantrelationshipwas foundbetweenthe lognumberoffecalbacteria and theprobability that anygivensamplewould containSalmonella.The likelihoodof finding Salmonella in grow-out pond waterincreased2.7 timeswitheach logunit increase infecalcoliformconcentrationand3.0timeswitheachlogunitincreaseinE. coliconcentration.Salmonella isnotpartofthenaturalfloraoftheshrimpcultureenvironmentnor is it inherentlypresent inshrimpgrow-out ponds.The occurrence of Salmonellabacteria in shrimp fromaquacultureoperations isrelatedtotheconcentrationof fecalbacteria inthesourceandgrow-outpondwater.

SapkotaA., SapkotaA.,KucharskiM.,Burke J.,McKenszieS.,WalkerP., LawrenceR., 2008:Aquaculture practices and potential healthrisks:Currentknowledgeand futurepriorities.Environ. Int. J., 34, 1215-1226.

　Theauthors conductedan extensive literature

searchwith145peer reviewedpapers to identifycurrent global aquaculture practices and thepotential health risks fromaquacultured seafood.Theauthors focusedonaquacultureproduction inAsiaashaving11ofthetop15producingcountriesin theworld.Thepaper identifies chemical andbiological contaminants usedby the aquacultureindustryand thepotential impactson foodsafetyand human health. Tables identify the top 15countries thatuseantibiotics and theprevalenceof antibiotic resistance in the environment as apotential health concern.As global aquacultureproductioncontinuestoincreaseworldwidewithanemphasisonintensivesystems,exposuretovarioushazardouschemicalandbiologicalcompounds isaconcern.Theauthorsconcludetheincreaseduseofchemotherapeuticagentsiscontributingtoelevatedlevelsofantibioticresiduesandantibioticresistantbacteria.

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