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Biosecurity and Fish Health Biosecurity and Fish Health Management for Management for 

Recirculating SystemsRecirculating Systems

Julie BebakJulie Bebak‐‐Williams, VMD, PhDWilliams, VMD, PhD

Freshwater Institute Freshwater Institute Shepherdstown, WVShepherdstown, WV

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Why are infectious disease outbreaks more likely to Why are infectious disease outbreaks more likely to occur in the RAS?occur in the RAS?

Fish loading densities greater than those used in pond Fish loading densities greater than those used in pond or serial reuse systemsor serial reuse systemsContinuous production strategiesContinuous production strategiesProlonged water retention in system provides extended Prolonged water retention in system provides extended residence time that allows for growth of opportunistic residence time that allows for growth of opportunistic and overtly virulent pathogensand overtly virulent pathogensRelatively more stressful environment Relatively more stressful environment

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Why does it matter (costs)?Why does it matter (costs)?CostsCosts

Diagnosis, response, diversion of management and labor, Diagnosis, response, diversion of management and labor, underutilization of production facilityunderutilization of production facilityDirect losses from mortalityDirect losses from mortalityReduced quality of survivorsReduced quality of survivorsInability to replace stockInability to replace stockRestricted market for healthy stock because of damage to Restricted market for healthy stock because of damage to reputation and missed marketsreputation and missed marketsRestriction of movement ordersRestriction of movement ordersFacility closure ordersFacility closure orders

Running a facility without a biosecurity and fish health management plan will result in these costs when an infectious disease outbreak occurs.

Note also that the higher capital and production costs of recirculatingsystems means that the consequences of infectious disease outbreaks can be catastrophic.

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What is biosecurity?What is biosecurity?

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Hazard reduction through Hazard reduction through environmental manipulationenvironmental manipulation

(Plumb, 1992)

Biosecurity

(Operating costs are reduced by minimizing the number and severity of disease outbreaks.)

Biosecurity accomplishes hazard reduction through environmental manipulation.Biosecurity cannot completely prevent entry of, or eliminate, all pathogensfrom a culture facility.Biosecurity accomplished pathogen reduction rather than pathogen elimination.

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Effective BiosecurityEffective Biosecurity

Reduces risk of pathogen introductionReduces risk of pathogen introductionReduces risk that pathogens will spread throughout the facilityReduces risk that pathogens will spread throughout the facilityReduces conditions that increase susceptibility to infection andReduces conditions that increase susceptibility to infection anddisease (e.g., reduce stress)disease (e.g., reduce stress)

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What is one strategy for What is one strategy for ““making upmaking up”” for losses?for losses?

Add extra fish.

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100,000 at Start100,000 at Start

22,46622,46630,20130,20126,70326,7033 3 InfInf

24,48824,48827,44927,44937,38937,3892 2 InfInf

25,79025,79031,59531,59576,06276,0621 1 InfInf

0.220.22--0.340.34

lbs/gallbs/gal

0.110.11--0.210.21

lbs/gallbs/gal

<0.11 <0.11 lbs/gallbs/gal

Starting Fish DensityP

ath

ogen

Dos

e

Can we compensate for losses to infectious disease by adding more fish to the system? No.

Numbers in cells of table are the number of fish left at the end of an outbreak for a given starting fish density and pathogen dose.

If we start with 100,000 fish, we have fewer left over at the end of the outbreak in the higher fish densities for a given pathogen dose (and higher pathogen doses for a given fish density)

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Effect of Pathogen DoseEffect of Pathogen Dose

02468

10121416

0 5 10 15 20 25 30 35 40 45 50 55 60

Time (days)

Dea

th r

ate

(%/d

ay)

1 Inf2 Inf3 InfAll Inf0 Inf

Example from an experiment evaluating the relationship between fish density and pathogen dose. This graph shows what happens to the death rate when the pathogen dose increases from 0 to 1,2,3 or all infectious fish added to varying densities of susceptible fish. The value for the death rate peaks gradually higher at 5.2, 5.9, 6.2 and 14.9 %/day for 1, 2, 3 and All Inf, respectively. The peak death rate occurs earlier and earlier 26, 25, 24 and 13 days for 1, 2, 3 and All Inf, respectively.

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Rule of ThumbRule of Thumb

Every producer that transports fish directly from a Every producer that transports fish directly from a pond into a recirculating system will experience pond into a recirculating system will experience

catastrophic losses from infectious disease catastrophic losses from infectious disease outbreaksoutbreaks

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Opportunistic vs. Obligate PathogensOpportunistic vs. Obligate Pathogens

Obligate pathogensObligate pathogensRequire animal host to replicate Require animal host to replicate Viruses (IPNV, IHNV, VHSV and OMV in salmonids); bacteria (bacteViruses (IPNV, IHNV, VHSV and OMV in salmonids); bacteria (bacterial kidney rial kidney disease, disease, furunculosisfurunculosis?, enteric ?, enteric redmouthredmouth disease)disease)

Opportunistic pathogensOpportunistic pathogensDo not require animal host to replicate Do not require animal host to replicate –– nutrition from organic materialnutrition from organic materialNaturally occur in soil and waterNaturally occur in soil and waterMay also be part of the natural microbial population in the fishMay also be part of the natural microbial population in the fish (e.g., the gastro(e.g., the gastro--intestinal tract)intestinal tract)Includes the species associated with bacterial gill disease, colIncludes the species associated with bacterial gill disease, coldwater disease, dwater disease, columnariscolumnaris disease, and the motile disease, and the motile aeromonadsaeromonads. Opportunistic parasites include . Opportunistic parasites include TrichodinaTrichodina, , ChilodonellaChilodonella, , IchthyobodoIchthyobodo??, , EpistylisEpistylis and and AmbiphyraAmbiphyra. The fungi can also be . The fungi can also be considered opportunistic pathogens. considered opportunistic pathogens.

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Biosecurity planning starts at the facility design Biosecurity planning starts at the facility design stagestage

Includes consideration ofIncludes consideration ofPlacement of doorsPlacement of doorsPlacement of disinfection areasPlacement of disinfection areas

Ventilation Ventilation –– to control insects, dust and aerosol transfer to control insects, dust and aerosol transfer (also can use barriers)(also can use barriers)

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Facility designFacility design

Reduce noise and vibrationReduce noise and vibrationArrange tanks so that they are easily accessibleArrange tanks so that they are easily accessibleAbility to take individual tanks and unit processes off Ability to take individual tanks and unit processes off line for cleaning or chemical treatmentline for cleaning or chemical treatmentConstruction materials Construction materials –– nonnon--porous and easy to clean porous and easy to clean and disinfect (plastic, metal, PVC)and disinfect (plastic, metal, PVC)Avoid use of wood (consider disposable)Avoid use of wood (consider disposable)Never transfer equipment to or from another siteNever transfer equipment to or from another site

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Circular Tanks & Solids RemovalCircular Tanks & Solids Removal

Advantages:Advantages:self cleaningself cleaningrapid solids fractionationrapid solids fractionationuniform environmentuniform environmentoptimum rotational velocityoptimum rotational velocity

for swimming fishfor swimming fish

flow distributes feed & fishflow distributes feed & fish

Solids fractionation – rapidly moving settleable solids to center drain so they don’t move out of side drain – leaves tank in 1 to 2 minutes and 5 minutes in a 30 foot tankCreate uniform environment as far as mixing, equal DO, Co2 ammoniaOptimal rotational velocity – 0.5 to 2.0 body lengths per second (12-30 cm/sec) compared to raceway which is much lower than 0.5 (2-4 cm/sec)Flow distributes feed and fish more evenly around the tank

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Circular Tanks w/o RotationCircular Tanks w/o RotationSolids must be Solids must be ““muckedmucked--outout”” of tank.of tank.

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Design features should be easy and Design features should be easy and convenient to useconvenient to use

White River NFH

Top of CO2 stripper at White River NFHDesigned by Brian, 8 feet diameterConstructed of panels with handles that are easy to remove and easier to clean, can do while in operation

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Clean Outs and ConeClean Outs and Cone--bottom Unit Processesbottom Unit Processes

Solids should not build up in any Solids should not build up in any part of systempart of system::

Easy to cleanEasy to cleanUnit processes (COUnit processes (CO22 stripper, LHO, stripper, LHO, biofilter) designed to be cleaned biofilter) designed to be cleaned (e.g., cone(e.g., cone--bottom, ability to drain)bottom, ability to drain)Include features to ease solids Include features to ease solids removal from system (e.g., clean removal from system (e.g., clean outs)outs)

Example of a cleanout – very important!

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CleanClean--Outs for Ozone ContactingOuts for Ozone Contacting

sedimenttrap

sedimenttrap

Floor drainto culture tanks

ozon

ated

inle

t

StrippingColumn

13-40 min O3Destruct

6-20 min O3Contact

Foam & O3Off-Gas

Separator

Fan

Lamar NFH (PA)

Note also cone-shaped unit processes that facilitates collection and emptying.

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CleanClean--Out Locations in all SumpsOut Locations in all Sumps

COCO22 & O& O22 ControlControl(Summerfelt et al., 2000)(Summerfelt et al., 2000)

LHO

cascade aeration column

Note the clean outs in the LHO sump and the CO2 stripperFrom the LHO sump to the fish tanks. An example of how you can take a unit process off line.

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Isolation of system componentsIsolation of system components

Tanks and unit processes that can be Tanks and unit processes that can be taken off linetaken off line & & drained out of systemdrained out of system

For cleaning while the rest of the system is operating, then For cleaning while the rest of the system is operating, then discharge out of the systemdischarge out of the systemFor chemical treatment of individual tanks, discharge to a For chemical treatment of individual tanks, discharge to a chemical drainchemical drain

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Bypass PipingBypass PipingDrain piping should be Drain piping should be plumbed to allow drum plumbed to allow drum filter bypass to direct filter bypass to direct flow to:flow to:

Drain (away from RAS)Drain (away from RAS)during cleaning eventsduring cleaning events

Pump sumpPump sumpWhen servicing drum When servicing drum filterfilter

drain

drum filterpump sump

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Bypass PipingBypass PipingCleanClean--outs with valves were installed at the end outs with valves were installed at the end of every pipe run.of every pipe run.Discharge tank & pipe cleaning flows into floor Discharge tank & pipe cleaning flows into floor trench.trench.

MCRA Hatchery, Delbarton, WV

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Sump DesignSump Design

Sump design with no standing waterSump design with no standing water

White River Nat’l Fish Hatchery

Sump on left side doesn’t drain, would be better if it slopes and collects to a drainProperly sized pipes move solids away from the system, used to be 8”, but now 4”. Dam boards were present with the 8” pipes, moved out dam boards and replaced with 4 inch so the whole thing drained more efficiently

Solids will settle where there are dead zones and low velocity pipes so removed dead zones and increased velocity to remove solids

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Fish health monitoring allows early detection Fish health monitoring allows early detection of a problemof a problem

Tank windowsTank windowsTwo locationsTwo locations

where healthiest fish would bewhere healthiest fish would bewhere sick fish would where sick fish would congregatecongregate

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Mort RemovalMort Removal

Design features to remove dead fishDesign features to remove dead fish““Mort FlushMort Flush””

Quantify mortalityQuantify mortalityReduce pathogen load on systemReduce pathogen load on systemRemove weak/moribund fish for examinationRemove weak/moribund fish for examination

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Unit processes in separate buildingUnit processes in separate building

White River NFH

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Avoid use of wood, unless disposableAvoid use of wood, unless disposable

Equipment used for Equipment used for sequential cohortssequential cohorts

PVC sheets instead of wood PVC sheets instead of wood sheetssheets

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MetalMetal

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PlasticPlasticInexpensive & Easy to DisinfectInexpensive & Easy to Disinfect

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I. Practices to Reduce the Risk of I. Practices to Reduce the Risk of Pathogen IntroductionPathogen Introduction

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Water SupplyWater Supply

SpecificSpecific--pathogen free (SPF) groundwater supplypathogen free (SPF) groundwater supplyFor both well and spring waterFor both well and spring water

Investigate possibility of surface water input (depends on surroInvestigate possibility of surface water input (depends on surrounding geology unding geology and depthand depthTest both before purchase of the propertyTest both before purchase of the property

Should be constructed to protect from surface water input and Should be constructed to protect from surface water input and entry of animals (e.g., invertebrates, amphibians, reptiles, entry of animals (e.g., invertebrates, amphibians, reptiles, mammals, birds) that could be carriers of pathogensmammals, birds) that could be carriers of pathogensIf surface water must be used, then it must be disinfected If surface water must be used, then it must be disinfected

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Eggs and FishEggs and Fish

SpecificSpecific--pathogenpathogen--free certified eggs/fishfree certified eggs/fishEggs disinfected upon arrivalEggs disinfected upon arrivalQuarantine new fish, certified or notQuarantine new fish, certified or notAvoid introduction of delivery waterAvoid introduction of delivery water

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FeedFeed

Live foodLive foodPresents a serious risk of contamination with pathogens Presents a serious risk of contamination with pathogens --should be should be cultured as specificcultured as specific--pathogenpathogen--free, never used directly from the free, never used directly from the natural environmentnatural environment

Commercial dry feedsCommercial dry feedsSteamSteam--pelletedpelleted –– 160160--180 F (71180 F (71--82 C)82 C)Expanded Expanded –– 180180--200 F (82200 F (82--93 C)93 C)Extruded Extruded –– 220220--350 F (104350 F (104--177 C)177 C)

Lyophilized feedLyophilized feedMany microorganisms survive Many microorganisms survive lyophilizationlyophilization wellwell

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People ManagementPeople Management

Frequent washing of hands and arms with antibacterial Frequent washing of hands and arms with antibacterial soap should be standard practicesoap should be standard practiceStrategically schedule culture activities (work on most Strategically schedule culture activities (work on most vulnerable stages first, minimize number of personnel vulnerable stages first, minimize number of personnel working on a group of fish, leave sick for last)working on a group of fish, leave sick for last)Disinfect vehicles before driving up to facilityDisinfect vehicles before driving up to facility

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People Management (cont.)People Management (cont.)

Visitor parking at periphery of facility groundsVisitor parking at periphery of facility groundsRestrict facility access to a minimum number of peopleRestrict facility access to a minimum number of peopleMinimize number of tours and limit to small, easily Minimize number of tours and limit to small, easily managed groupsmanaged groupsMaintain log bookMaintain log bookVisitors (not at aquaculture facility w/in past 48 hours) Visitors (not at aquaculture facility w/in past 48 hours) –– coveralls over clothing, disinfected boots, wash with coveralls over clothing, disinfected boots, wash with antibacterial soap for 30 secondsantibacterial soap for 30 seconds

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Visitor ControlVisitor Control

Can use signs, rope and cones to control visitor and personnel movement

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People Management (cont.)People Management (cont.)

Visitors (at aquaculture facility w/in past 48 hours) Visitors (at aquaculture facility w/in past 48 hours) ––remove clothes, put on coveralls and disinfected boots, remove clothes, put on coveralls and disinfected boots, wash with antibacterial soapwash with antibacterial soapInstruct visitors not to touch, or lean on, anything in Instruct visitors not to touch, or lean on, anything in culture roomculture roomChange footbaths and disinfect floors after every tourChange footbaths and disinfect floors after every tour

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FootbathFootbath

Incorrect use of a footbath – dirty boots and footbath is almost dry.

Footwear going in should be clean and foot bath solution should be clean and at least one to two inches above the top of the material in the footbath

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QuarantineQuarantine

Planned early in the design of the facilityPlanned early in the design of the facilitySeparate building, room or area with independent, Separate building, room or area with independent, isolated culture systemisolated culture systemQ period accounts for incubation and development Q period accounts for incubation and development times for targeted pathogenstimes for targeted pathogensWater temperature kept at upper end of fish species Water temperature kept at upper end of fish species optimum range to speed up pathogen life cyclesoptimum range to speed up pathogen life cycles

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Quarantine (cont.)Quarantine (cont.)

Observe new arrivals for abnormalities in appearance Observe new arrivals for abnormalities in appearance and behavior, sample and examineand behavior, sample and examineThroughout Q period, sample normal and abnormal Throughout Q period, sample normal and abnormal fish, examinefish, examineHold fish at culture densities they will encounter in Hold fish at culture densities they will encounter in production systemproduction system

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Quarantine (cont.)Quarantine (cont.)

Wash hands and arms before going between quarantine and Wash hands and arms before going between quarantine and production area. Disinfect production area. Disinfect footwarefootware. Change clothing.. Change clothing.Save work in Q area as last element of the work daySave work in Q area as last element of the work dayUse Q equipment only in the Q areaUse Q equipment only in the Q areaAcclimate fish to production system water by introducing it to Acclimate fish to production system water by introducing it to quarantine before transfer out of quarantinequarantine before transfer out of quarantine

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II. Practices to Reduce Pathogen SpreadII. Practices to Reduce Pathogen Spread

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Meticulous husbandryMeticulous husbandry

An example of a dirty system

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HusbandryHusbandry

Install deep foot baths, clean and change frequentlyInstall deep foot baths, clean and change frequentlyWash hands and arms before entering fish culture area Wash hands and arms before entering fish culture area and as change work with groups of fishand as change work with groups of fishEasily accessible disinfectant and rinse areas (e.g., for Easily accessible disinfectant and rinse areas (e.g., for buckets, nets, meters)buckets, nets, meters)

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Disinfection areaDisinfection area

Three sink method: First sink for dirty equipment and for hand washing, second sink has disinfect and third sink is for rinsing disinfected equipment only

Trash cans: One has disinfectant, the other is the rinse, with constant flow of water through it

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Husbandry (cont.)Husbandry (cont.)

Store clean equipment in a clean areaStore clean equipment in a clean areaMeticulous husbandry proceduresMeticulous husbandry proceduresEven for recycle loop, treat each tank as a discrete Even for recycle loop, treat each tank as a discrete rearing unit, minimize potential for crossrearing unit, minimize potential for cross--contaminationcontaminationDisinfect tanks and equipment before use with a Disinfect tanks and equipment before use with a different group of fishdifferent group of fish

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Husbandry (cont.)Husbandry (cont.)

Regard floor as contaminated, manage accordinglyRegard floor as contaminated, manage accordinglyClean floors frequentlyClean floors frequentlyInspect and clean all parts of system frequentlyInspect and clean all parts of system frequentlyExclude pets, rodents, birds, other vertebrates and Exclude pets, rodents, birds, other vertebrates and insects from culture areainsects from culture area

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DefinitionsDefinitionsSurfactant Surfactant –– ''SURFaceSURFace ACTiveACTive AgeNTAgeNT' ' -- a molecule that lowers a molecule that lowers sufacesufacetension; contain both hydrophobic and hydrophilic components so tension; contain both hydrophobic and hydrophilic components so are are semisemi--soluble in both organic and aqueous solvents; the hydrophobic soluble in both organic and aqueous solvents; the hydrophobic component sticks to grease and dirt while the hydrophilic sectiocomponent sticks to grease and dirt while the hydrophilic section sticks to n sticks to the water; active ingredient in soapthe water; active ingredient in soap

Disinfectant Disinfectant –– eliminates virtually all recognized pathogenic eliminates virtually all recognized pathogenic microorganisms; an agent that kills or inactivates >99.99% of dimicroorganisms; an agent that kills or inactivates >99.99% of disease sease causing microorganisms, may not kill sporescausing microorganisms, may not kill spores

Sanitizer Sanitizer –– an agent that decreases the load of microorganisms (not an agent that decreases the load of microorganisms (not necessarily pathogenic)necessarily pathogenic)

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Surfactant ExampleSurfactant Example

““Simple GreenSimple Green””Cleaner and degreaserCleaner and degreaserListed as nonhazardous, nonListed as nonhazardous, non--mutagenic, nonmutagenic, non--carcinogeniccarcinogenicOn a scale of 1 to 4, ranked as 1 for slight health hazard becauOn a scale of 1 to 4, ranked as 1 for slight health hazard because it can se it can be a mild eye irritant (mucous membrane irritation concentrate mbe a mild eye irritant (mucous membrane irritation concentrate mist)ist)No special ventilation is required during useNo special ventilation is required during useMeets EPA and OECD recommendations for ready biodegradability; Meets EPA and OECD recommendations for ready biodegradability; practically nonpractically non--toxic per EPAtoxic per EPA’’s aquatic toxicity scales aquatic toxicity scaleComponents on TSCA Chemical Substance InventoryComponents on TSCA Chemical Substance Inventory

OECD – Organization for Economic Cooperation and Development

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DisinfectantsDisinfectants

Factors affecting disinfection processFactors affecting disinfection processTypeTypeConcentrationConcentrationTemperatureTemperatureContact TimeContact TimepHpHPresence of soil/organic matterPresence of soil/organic matterNumber of organismsNumber of organismsType and growth phase of organismType and growth phase of organism

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IodophorIodophor

RegsRegsSafe for environmentSafe for environment

Test stripsTest stripsTests for active chemical residues?Tests for active chemical residues?Dissipates slowlyDissipates slowlyStable?Stable?YesYesLeaves active residue?Leaves active residue?NoNoSurfactant activity?Surfactant activity?SlightlySlightlyCorrosive?Corrosive?Skin and eye irritationSkin and eye irritationNonNon--toxic humans?toxic humans?Depends on dilutionDepends on dilutionNonNon--toxic fish?toxic fish?

Yes, but turns yellow & is more stable than chlorineYes, but turns yellow & is more stable than chlorineInactivated by soil/organic matter?Inactivated by soil/organic matter?

NoNoBroad spectrum (inactivates IPNV)?Broad spectrum (inactivates IPNV)?

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Quaternary Ammonium Compounds (Quaternary Ammonium Compounds (QACsQACs))

RegsRegsSafe for environmentSafe for environment

Test stripsTest stripsTests for active chemical Tests for active chemical residues?residues?

YesYesStable?Stable?YesYesLeaves active residue?Leaves active residue?YesYesSurfactant activity?Surfactant activity?NoNoCorrosive?Corrosive?

Corrosive to skin and eyes; Irritation of respiratory Corrosive to skin and eyes; Irritation of respiratory tract; headache, drowsinesstract; headache, drowsiness

NonNon--toxic humans?toxic humans?Depends on dilutionDepends on dilutionNonNon--toxic fish?toxic fish?

Moderately stableModerately stableInactivated by soil/organic Inactivated by soil/organic matter?matter?

NoNoBroad spectrum (inactivates Broad spectrum (inactivates IPNV)?IPNV)?

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Hypochlorite (HTH)Hypochlorite (HTH)

RegsRegs (must be neutralized with sodium thiosulfate)(must be neutralized with sodium thiosulfate)Safe for environmentSafe for environment

Test stripsTest stripsTests for active chemical Tests for active chemical residues?residues?

No, dissipates rapidlyNo, dissipates rapidlyStable?Stable?NoNoLeaves active residue?Leaves active residue?V. slightV. slightSurfactant activity?Surfactant activity?Yes, to metals and plasticsYes, to metals and plasticsCorrosive?Corrosive?

Dust causes skin, eye, digestive tract and respiratory burnsDust causes skin, eye, digestive tract and respiratory burnsNonNon--toxic humans?toxic humans?Extremely toxic at low concentrationsExtremely toxic at low concentrationsNonNon--toxic fish?toxic fish?

YesYesInactivated by soil/organic Inactivated by soil/organic matter?matter?

YesYesBroad spectrum (inactivates Broad spectrum (inactivates IPNV)?IPNV)?

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VirkonVirkon--SS(potassium (potassium monopersulfatemonopersulfate))

RegsRegs., breaks down to harmless organic salt., breaks down to harmless organic saltSafe for environmentSafe for environment

??Tests for active chemical Tests for active chemical residues?residues?

Dissipates Dissipates veryvery slowlyslowlyStable?Stable???Leaves active residue?Leaves active residue?Yes (including bacterial biofilms)Yes (including bacterial biofilms)Surfactant activity?Surfactant activity?To metals but not nettingTo metals but not nettingCorrosive?Corrosive?

As powder can be respiratory and eye irritantAs powder can be respiratory and eye irritantNonNon--toxic humans?toxic humans?Depends on dilutionDepends on dilutionNonNon--toxic fish?toxic fish?

??Inactivated by soil/organic Inactivated by soil/organic matter?matter?

YesYesBroad spectrum (inactivates Broad spectrum (inactivates IPNV)?IPNV)?

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CullingCulling

An important strategy to reduce transmission of An important strategy to reduce transmission of pathogenspathogensShould include sick (as long as cause is infectious) as Should include sick (as long as cause is infectious) as well as dead fishwell as dead fishCull at least once per dayCull at least once per dayFish should be killed humanely, not allowed to die Fish should be killed humanely, not allowed to die from suffocationfrom suffocation

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Additional StrategiesAdditional Strategies

Changing flow to increase turnover ratesChanging flow to increase turnover ratesDensity manipulationDensity manipulation

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Culture ActivitiesCulture Activities

Minimize the number of different personnel working Minimize the number of different personnel working with a group of fishwith a group of fishUnaffected tanks should be worked on before affected Unaffected tanks should be worked on before affected tankstanksCare for young fish before older fishCare for young fish before older fishEquipment touching the floor should not contact fish Equipment touching the floor should not contact fish culture waterculture waterFish that jump from tank to floor should be humanely Fish that jump from tank to floor should be humanely killed, not returned to tankkilled, not returned to tank

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III. Practices to Reduce Susceptibility to III. Practices to Reduce Susceptibility to Infection and DiseaseInfection and Disease

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Strategies for a Strong Immune SystemStrategies for a Strong Immune System

Optimum nutritionOptimum nutritionFish should be from Fish should be from optimum year class brood optimum year class brood stockstockGentle handling to reduce Gentle handling to reduce stress and injurystress and injuryVaccinationVaccination

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IV. MonitoringIV. Monitoring

Set up a monitoring Set up a monitoring and response planand response plan

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Record KeepingRecord Keeping

Used to track changesUsed to track changesUsed to improve biosecurity protocolsUsed to improve biosecurity protocolsIncludes water quality, feed fed, feed lot numbers, Includes water quality, feed fed, feed lot numbers, visitors, number of dead and culled fish, observations visitors, number of dead and culled fish, observations of abnormalities, laboratory results, results of of abnormalities, laboratory results, results of treatmenttreatment

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Monitor Water Quality!Monitor Water Quality!

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Know normal vs. abnormal behavioral and Know normal vs. abnormal behavioral and physical signs for stress and illnessphysical signs for stress and illness

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Behavioral and Physical Signs for Behavioral and Physical Signs for Stress/IllnessStress/Illness

MovementMovementWeak, erratic, lethargic swimmingWeak, erratic, lethargic swimmingAbnormal reaction to external stimuli such as noise or Abnormal reaction to external stimuli such as noise or movementmovementScratching, flashing, rubbing against tank walls or bottomScratching, flashing, rubbing against tank walls or bottomTwitching, darting, spinning or jumping out of waterTwitching, darting, spinning or jumping out of waterCrowding at Crowding at inflentinflent water supplywater supplySwimming upside downSwimming upside downGasping at water surfaceGasping at water surface

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Behavioral and Physical Signs for Behavioral and Physical Signs for Stress/IllnessStress/Illness

FeedingFeedingNot feedingNot feedingReduced feeding (detected by system TAN and growth Reduced feeding (detected by system TAN and growth curves as well as observation)curves as well as observation)

BreathingBreathingDecreased or increased rate of Decreased or increased rate of opercularopercular movementmovement

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Behavioral and Physical Signs for Stress/IllnessBehavioral and Physical Signs for Stress/IllnessPhysical ConditionPhysical Condition

Visible lesions or soresVisible lesions or soresCloudy eyes, protruding eyesCloudy eyes, protruding eyesGillsGills swollen, white, pink or swollen, white, pink or pale red, eroded, puffy, pale red, eroded, puffy, bloody, brownbloody, brownScale lossScale lossSwollen abdomenSwollen abdomenDiarrheaDiarrhea

Excess mucus on skin/gills Excess mucus on skin/gills (check for excess mucus on (check for excess mucus on tank screens)tank screens)Spots, fungus on skinSpots, fungus on skinUnusual coloration on body Unusual coloration on body surfacesurfaceFlared operculaFlared operculaFrayed fins or tailFrayed fins or tailBubbles in eyes, skin, gillsBubbles in eyes, skin, gills

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Submersible Biomass ScannerSubmersible Biomass Scanner

VAKI DNG (VAKI DNG (KKóópavogurpavogur, , IcelandIceland))

Used to track Arctic char size & growth at CFFI.

What principle does the VAKI scanner work on? Infrared diode array note the contour of the fish to get shape profile from top and side – works at 100 kg/m3

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V. DiagnosisV. Diagnosis

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Supplies/Equipment for Fish Health Supplies/Equipment for Fish Health LaboratoryLaboratory

Compound microscope (with 10X ocular and 4X, 10X, Compound microscope (with 10X ocular and 4X, 10X, and 40X objectives)and 40X objectives)Slides, cover slipsSlides, cover slipsDissecting kit (for large and small fish)Dissecting kit (for large and small fish)Anesthetic (e.g., Anesthetic (e.g., tricainetricaine methane methane sulfonatesulfonate (MS(MS--222))222))

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DiagnosisDiagnosis

Keep accurate records so that an accurate history can Keep accurate records so that an accurate history can be compiledbe compiledLearn normal and abnormal appearance and behaviorLearn normal and abnormal appearance and behaviorEvaluate water qualityEvaluate water qualityLearn skin scrape and gill biopsy techniques to identify Learn skin scrape and gill biopsy techniques to identify parasitesparasitesFind an aquaculture veterinarianFind an aquaculture veterinarian

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DiagnosisDiagnosis

An accurate diagnosis is essentialAn accurate diagnosis is essentialDetermines treatment regimen (whether, and which, Determines treatment regimen (whether, and which, chemotherapeutantschemotherapeutants should be used)should be used)Treatment based on hunches results in wasted time and Treatment based on hunches results in wasted time and money and further degradation of the fishmoney and further degradation of the fishIncorrect diagnosis prevents development of an effective Incorrect diagnosis prevents development of an effective strategy to prevent recurrencestrategy to prevent recurrence

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TreatmentTreatment

Disease from water quality more likely in a Disease from water quality more likely in a biosecurebiosecurerecirculating system (slow turnover rate)recirculating system (slow turnover rate)If chemical treatment is necessary, effect on biofilter must be If chemical treatment is necessary, effect on biofilter must be considered (Table 13.3) (design system for biofilter bypass considered (Table 13.3) (design system for biofilter bypass during treatment)during treatment)When treating the whole system, slow turnover rate means When treating the whole system, slow turnover rate means chemical might need to be applied at a lower concentration for chemical might need to be applied at a lower concentration for a longer perioda longer periodTake individual tanks offTake individual tanks off--line for bath or flowline for bath or flow--through through treatment treatment

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Case Study #1Case Study #1

Recirculating salmonid facilityRecirculating salmonid facilitySpecificSpecific--pathogenpathogen--free eggsfree eggs

Biosecurity recommendations included disinfection of eggs with Biosecurity recommendations included disinfection of eggs with iodophoriodophor upon arrival from supplierupon arrival from supplier

SpecificSpecific--pathogenpathogen--free water supplyfree water supplyDesign criteria included clean outsDesign criteria included clean outs

Attention to biosecurity appeared to be excellent but Attention to biosecurity appeared to be excellent but after one year, saw systemafter one year, saw system--wide fungal infections and wide fungal infections and upon routine inspection fish were infected with upon routine inspection fish were infected with AeromonasAeromonas salmonicidasalmonicida ((furunculosisfurunculosis))

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Case Study #1 (cont.)Case Study #1 (cont.)

RecommendationsRecommendationsFungi growing on solids substrates, so system maintenance is oveFungi growing on solids substrates, so system maintenance is overdue rdue –– itit’’s time to get into the cleanouts and get the solids out of the s time to get into the cleanouts and get the solids out of the system, also, use formalin to treat affected fish.system, also, use formalin to treat affected fish.

Some of the clean outs were not installed, others were concretedSome of the clean outs were not installed, others were concreted in. As a result, in. As a result, needed to try to access the pipes from hardneeded to try to access the pipes from hard--toto--reach areas reach areas –– continually coping continually coping with chronic, lowwith chronic, low--level fungal infections in the system level fungal infections in the system –– install cleanouts after install cleanouts after system builtsystem built

Regarding the Regarding the furunculosisfurunculosis bacteria bacteria –– recommendations to disinfect recommendations to disinfect eggs upon arrival were not followed because eggs upon arrival were not followed because ““the supplier disinfected the supplier disinfected them before shippingthem before shipping”” –– they are now disinfecting eggs upon arrivalthey are now disinfecting eggs upon arrival

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Case Study #2 Case Study #2 (or, if we do everything you say, will we (or, if we do everything you say, will we

experience disease outbreaks?)experience disease outbreaks?)FI research system FI research system –– a a biosecurebiosecure systemsystem

Spring water supplySpring water supplyNo infectious disease problems except chronic, recurring No infectious disease problems except chronic, recurring respiratory diseaserespiratory diseaseA A ““newnew”” pathogen pathogen –– chlamydiachlamydia--like/rickettsialike/rickettsia--likelike bacteria bacteria that infects gill cellsthat infects gill cellsIdentification of organism, development of prevention and Identification of organism, development of prevention and control strategies are in progresscontrol strategies are in progress

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Current/Future Issues in Biosecurity of Current/Future Issues in Biosecurity of Recirculating SystemsRecirculating Systems

The safety of The safety of ““diseasedisease--freefree”” ground water suppliesground water suppliesOpportunistic pathogens present in recirculating Opportunistic pathogens present in recirculating systems that come from the fish or from the systems that come from the fish or from the environmentenvironment

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Biosecurity programs should be dynamic, re-evaluate and

change as necessary