Biosecurity and Fish Biosecurity and Fish Health Management for Health Management for Recirculating SystemsRecirculating Systems
Julie Bebak-Williams, VMD, PhDJulie Bebak-Williams, VMD, PhD
Freshwater Institute Freshwater Institute
Shepherdstown, WVShepherdstown, WV
Why are infectious disease outbreaks Why are infectious disease outbreaks more likely to occur in the RAS?more likely to occur in the RAS?
Fish loading densities greater than those Fish loading densities greater than those used in pond or serial reuse systemsused in pond or serial reuse systems
Continuous production strategiesContinuous production strategies Prolonged water retention in system Prolonged water retention in system
provides extended residence time that provides extended residence time that allows for growth of opportunistic and allows for growth of opportunistic and overtly virulent pathogensovertly virulent pathogens
Relatively more stressful environment Relatively more stressful environment
Why does it matter (costs)?Why does it matter (costs)? CostsCosts
Diagnosis, response, diversion of management Diagnosis, response, diversion of management and labor, underutilization of production facilityand labor, underutilization of production facility
Direct losses from mortalityDirect losses from mortality Reduced quality of survivorsReduced quality of survivors Inability to replace stockInability to replace stock Restricted market for healthy stock because of Restricted market for healthy stock because of
damage to reputation and missed marketsdamage to reputation and missed markets Restriction of movement ordersRestriction of movement orders Facility closure ordersFacility closure orders
What is biosecurity?What is biosecurity?
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.)
Effective BiosecurityEffective Biosecurity
Reduces risk of pathogen introductionReduces risk of pathogen introduction Reduces risk that pathogens will spread throughout Reduces risk that pathogens will spread throughout
the facilitythe facility Reduces conditions that increase susceptibility to Reduces conditions that increase susceptibility to
infection and disease (e.g., reduce stress)infection and disease (e.g., reduce stress)
What is one strategy What is one strategy for “making up” for for “making up” for
losses?losses?
100,000 at Start100,000 at Start
<0.11 <0.11 lbs/gallbs/gal
0.11-0.210.11-0.21
lbs/gallbs/gal0.22-0.340.22-0.34
lbs/gallbs/gal
1 Inf1 Inf 76,06276,062 31,59531,595 25,79025,790
2 Inf2 Inf 37,38937,389 27,44927,449 24,48824,488
3 Inf3 Inf 26,70326,703 30,20130,201 22,46622,466
Starting Fish Density
Path
og
en
D
ose
Effect of Pathogen DoseEffect of Pathogen Dose
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35 40 45 50 55 60
Time (days)
Dea
th r
ate
(%/d
ay) 1 Inf
2 Inf
3 Inf
All Inf
0 Inf
Rule of ThumbRule of Thumb
Every producer that transports fish Every producer that transports fish directly from a pond into a recirculating directly from a pond into a recirculating
system will experience catastrophic system will experience catastrophic losses from infectious disease outbreakslosses from infectious disease outbreaks
Opportunistic vs. Obligate Opportunistic vs. Obligate PathogensPathogens
Obligate pathogensObligate pathogens Require animal host to replicate Require animal host to replicate Viruses (IPNV, IHNV, VHSV and OMV in salmonids); bacteria Viruses (IPNV, IHNV, VHSV and OMV in salmonids); bacteria
(bacterial kidney disease, furunculosis?, enteric redmouth (bacterial kidney disease, furunculosis?, enteric redmouth disease)disease)
Opportunistic pathogensOpportunistic pathogens Do not require animal host to replicate – nutrition from organic Do not require animal host to replicate – nutrition from organic
materialmaterial Naturally occur in soil and waterNaturally occur in soil and water May also be part of the natural microbial population in the fish May also be part of the natural microbial population in the fish
(e.g., the gastro-intestinal tract)(e.g., the gastro-intestinal tract) Includes the species associated with bacterial gill disease, Includes the species associated with bacterial gill disease,
coldwater disease, columnaris disease, and the motile coldwater disease, columnaris disease, and the motile aeromonads. Opportunistic parasites include aeromonads. Opportunistic parasites include TrichodinaTrichodina, , ChilodonellaChilodonella, , Ichthyobodo?Ichthyobodo?, , EpistylisEpistylis and and AmbiphyraAmbiphyra. The fungi . The fungi can also be considered opportunistic pathogens. can also be considered opportunistic pathogens.
Biosecurity planning starts at the Biosecurity planning starts at the facility design stagefacility design stage
Includes consideration ofIncludes consideration of Placement of doorsPlacement of doors Placement of disinfection areasPlacement of disinfection areas
Ventilation – to control insects, dust and Ventilation – to control insects, dust and aerosol transfer (also can use barriers)aerosol transfer (also can use barriers)
Facility designFacility design
Reduce noise and vibrationReduce noise and vibration Arrange tanks so that they are easily accessibleArrange tanks so that they are easily accessible Ability to take individual tanks and unit processes Ability to take individual tanks and unit processes
off line for cleaning or chemical treatmentoff line for cleaning or chemical treatment Construction materials – non-porous and easy to Construction materials – non-porous and easy to
clean and disinfect (plastic, metal, PVC)clean 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
Circular Tanks & Solids Circular Tanks & Solids RemovalRemoval
Advantages:Advantages: self cleaningself cleaning rapid solids rapid solids
fractionationfractionation uniform environmentuniform environment optimum rotational optimum rotational
velocityvelocity for swimming fishfor swimming fish
flow distributes feed flow distributes feed & fish& fish
Circular Tanks w/o Circular Tanks w/o RotationRotation
Solids must be “mucked-out” of Solids must be “mucked-out” of tank.tank.
Design features should be easy Design features should be easy and convenient to useand convenient to use
White River NFH
Clean Outs and Cone-bottom Unit Clean Outs and Cone-bottom Unit ProcessesProcesses
Solids should not build up Solids should not build up in any part of systemin any part of system:: Easy to cleanEasy to clean Unit processes (COUnit processes (CO22
stripper, LHO, biofilter) stripper, LHO, biofilter) designed to be cleaned designed to be cleaned (e.g., cone-bottom, ability (e.g., cone-bottom, ability to drain)to drain)
Include features to ease Include features to ease solids removal from system solids removal from system (e.g., clean outs)(e.g., clean outs)
Clean-Outs for Ozone ContactingClean-Outs for Ozone Contacting
sedimenttrap
sedimenttrap
Floor drainto culture tanks
ozon
ated
inle
t
StrippingColumn
13-40 min O3
Destruct
6-20 min O3
Contact
Foam & O3
Off-GasSeparator
Fan
Lamar NFH (PA)
Clean-Out Locations in all Clean-Out Locations in all SumpsSumps
COCO22 & O & O22 Control Control(Summerfelt et al., 2000)(Summerfelt et al., 2000)
LHO
cascade aeration column
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 system & drained out of system For cleaning while the rest of the system is For cleaning while the rest of the system is
operating, then discharge out of the systemoperating, then discharge out of the system For chemical treatment of individual tanks, For chemical treatment of individual tanks,
discharge to a chemical draindischarge to a chemical drain
Bypass PipingBypass Piping Drain piping should Drain piping should
be plumbed to allow be plumbed to allow drum filter bypass to drum filter bypass to direct flow to:direct flow to: Drain (away from Drain (away from
RAS)RAS) during cleaning during cleaning
eventsevents Pump sumpPump sump
When servicing drum When servicing drum filterfilter
drain
drum filterpump sump
Bypass PipingBypass Piping Clean-outs with valves were installed Clean-outs with valves were installed
at the end of every pipe run.at the end of every pipe run. Discharge tank & pipe cleaning flows Discharge tank & pipe cleaning flows
into floor trench.into floor trench.
MCRA Hatchery, Delbarton, WV
Sump DesignSump Design
Sump design with no standing waterSump design with no standing water
White River Nat’l Fish Hatchery
Fish health monitoring allows Fish health monitoring allows early detection of a problemearly detection of a problem
Tank windowsTank windows Two locationsTwo locations
where healthiest fish where healthiest fish would bewould be
where sick fish would where sick fish would congregatecongregate
Mort RemovalMort Removal
Design features to remove dead fishDesign features to remove dead fish ““Mort Flush”Mort Flush”
Quantify mortalityQuantify mortality Reduce pathogen load on systemReduce pathogen load on system Remove weak/moribund fish for examinationRemove weak/moribund fish for examination
Unit processes in separate Unit processes in separate buildingbuilding
White River NFH
Avoid use of wood, unless Avoid use of wood, unless disposabledisposable
Equipment used for Equipment used for sequential cohortssequential cohorts
PVC sheets instead of PVC sheets instead of wood sheetswood sheets
MetalMetal
PlasticPlasticInexpensive & Easy to DisinfectInexpensive & Easy to Disinfect
I. Practices to Reduce the Risk I. Practices to Reduce the Risk of Pathogen Introductionof Pathogen Introduction
Water SupplyWater Supply
Specific-pathogen free (SPF) groundwater supplySpecific-pathogen free (SPF) groundwater supply For both well and spring waterFor both well and spring water
Investigate possibility of surface water input (depends on Investigate possibility of surface water input (depends on surrounding geology and depthsurrounding geology and depth
Test both before purchase of the propertyTest both before purchase of the property
Should be constructed to protect from surface Should be constructed to protect from surface water input and entry of animals (e.g., water input and entry of animals (e.g., invertebrates, amphibians, reptiles, mammals, invertebrates, amphibians, reptiles, mammals, birds) that could be carriers of pathogensbirds) that could be carriers of pathogens
If surface water must be used, then it must be If surface water must be used, then it must be disinfected disinfected
Eggs and FishEggs and Fish
Specific-pathogen-free certified eggs/fishSpecific-pathogen-free certified eggs/fish Eggs disinfected upon arrivalEggs disinfected upon arrival Quarantine new fish, certified or notQuarantine new fish, certified or not Avoid introduction of delivery waterAvoid introduction of delivery water
FeedFeed
Live foodLive food Presents a serious risk of contamination with Presents a serious risk of contamination with
pathogens -should be cultured as specific-pathogen-pathogens -should be cultured as specific-pathogen-free, never used directly from the natural environmentfree, never used directly from the natural environment
Commercial dry feedsCommercial dry feeds Steam-pelleted – 160-180 F (71-82 C)Steam-pelleted – 160-180 F (71-82 C) Expanded – 180-200 F (82-93 C)Expanded – 180-200 F (82-93 C) Extruded – 220-350 F (104-177 C)Extruded – 220-350 F (104-177 C)
Lyophilized feedLyophilized feed Many microorganisms survive lyophilization wellMany microorganisms survive lyophilization well
People ManagementPeople Management
Frequent washing of hands and arms with Frequent washing of hands and arms with antibacterial soap should be standard antibacterial soap should be standard practicepractice
Strategically schedule culture activities Strategically schedule culture activities (work on most vulnerable stages first, (work on most vulnerable stages first, minimize number of personnel working minimize number of personnel working on a group of fish, leave sick for last)on a group of fish, leave sick for last)
Disinfect vehicles before driving up to Disinfect vehicles before driving up to facilityfacility
People Management (cont.)People Management (cont.)
Visitor parking at periphery of facility groundsVisitor parking at periphery of facility grounds Restrict facility access to a minimum number of Restrict facility access to a minimum number of
peoplepeople Minimize number of tours and limit to small, Minimize number of tours and limit to small,
easily managed groupseasily managed groups Maintain log bookMaintain log book Visitors (not at aquaculture facility w/in past 48 Visitors (not at aquaculture facility w/in past 48
hours) – coveralls over clothing, disinfected hours) – coveralls over clothing, disinfected boots, wash with antibacterial soap for 30 boots, wash with antibacterial soap for 30 secondsseconds
Visitor ControlVisitor Control
People Management (cont.)People Management (cont.)
Visitors (at aquaculture facility w/in past Visitors (at aquaculture facility w/in past 48 hours) – remove clothes, put on 48 hours) – remove clothes, put on coveralls and disinfected boots, wash coveralls and disinfected boots, wash with antibacterial soapwith antibacterial soap
Instruct visitors not to touch, or lean on, Instruct visitors not to touch, or lean on, anything in culture roomanything in culture room
Change footbaths and disinfect floors Change footbaths and disinfect floors after every tourafter every tour
FootbathFootbath
QuarantineQuarantine Planned early in the design of the facilityPlanned early in the design of the facility Separate building, room or area with Separate building, room or area with
independent, isolated culture systemindependent, isolated culture system Q period accounts for incubation and Q period accounts for incubation and
development times for targeted pathogensdevelopment times for targeted pathogens Water temperature kept at upper end of Water temperature kept at upper end of
fish species optimum range to speed up fish species optimum range to speed up pathogen life cyclespathogen life cycles
Quarantine (cont.)Quarantine (cont.)
Observe new arrivals for abnormalities in Observe new arrivals for abnormalities in appearance and behavior, sample and appearance and behavior, sample and examineexamine
Throughout Q period, sample normal and Throughout Q period, sample normal and abnormal fish, examineabnormal fish, examine
Hold fish at culture densities they will Hold fish at culture densities they will encounter in production systemencounter in production system
Quarantine (cont.)Quarantine (cont.)
Wash hands and arms before going between Wash hands and arms before going between quarantine and production area. Disinfect quarantine and production area. Disinfect footware. Change clothing.footware. Change clothing.
Save work in Q area as last element of the work Save work in Q area as last element of the work dayday
Use Q equipment only in the Q areaUse Q equipment only in the Q area Acclimate fish to production system water by Acclimate fish to production system water by
introducing it to quarantine before transfer out introducing it to quarantine before transfer out of quarantineof quarantine
II. Practices to Reduce II. Practices to Reduce Pathogen SpreadPathogen Spread
Meticulous husbandryMeticulous husbandry
HusbandryHusbandry
Install deep foot baths, clean and change Install deep foot baths, clean and change frequentlyfrequently
Wash hands and arms before entering Wash hands and arms before entering fish culture area and as change work with fish culture area and as change work with groups of fishgroups of fish
Easily accessible disinfectant and rinse Easily accessible disinfectant and rinse areas (e.g., for buckets, nets, meters)areas (e.g., for buckets, nets, meters)
Disinfection areaDisinfection area
Husbandry (cont.)Husbandry (cont.)
Store clean equipment in a clean areaStore clean equipment in a clean area Meticulous husbandry proceduresMeticulous husbandry procedures Even for recycle loop, treat each tank as Even for recycle loop, treat each tank as
a discrete rearing unit, minimize a discrete rearing unit, minimize potential for cross-contaminationpotential for cross-contamination
Disinfect tanks and equipment before use Disinfect tanks and equipment before use with a different group of fishwith a different group of fish
Husbandry (cont.)Husbandry (cont.)
Regard floor as contaminated, manage Regard floor as contaminated, manage accordinglyaccordingly
Clean floors frequentlyClean floors frequently Inspect and clean all parts of system Inspect and clean all parts of system
frequentlyfrequently Exclude pets, rodents, birds, other Exclude pets, rodents, birds, other
vertebrates and insects from culture areavertebrates and insects from culture area
DefinitionsDefinitions Surfactant – 'SURFace ACTive AgeNT' - a molecule that Surfactant – 'SURFace ACTive AgeNT' - a molecule that
lowers suface tension; contain both hydrophobic and lowers suface tension; contain both hydrophobic and hydrophilic components so are semi-soluble in both organic hydrophilic components so are semi-soluble in both organic and aqueous solvents; the hydrophobic component sticks to and aqueous solvents; the hydrophobic component sticks to grease and dirt while the hydrophilic section sticks to the grease and dirt while the hydrophilic section sticks to the water; active ingredient in soapwater; active ingredient in soap
Disinfectant – eliminates virtually all recognized pathogenic Disinfectant – eliminates virtually all recognized pathogenic microorganisms; an agent that kills or inactivates >99.99% microorganisms; an agent that kills or inactivates >99.99% of disease causing microorganisms, may not kill sporesof disease causing microorganisms, may not kill spores
Sanitizer – an agent that decreases the load of Sanitizer – an agent that decreases the load of microorganisms (not necessarily pathogenic)microorganisms (not necessarily pathogenic)
Surfactant ExampleSurfactant Example ““Simple Green”Simple Green”
Cleaner and degreaserCleaner and degreaser Listed as nonhazardous, non-mutagenic, non-Listed as nonhazardous, non-mutagenic, non-
carcinogeniccarcinogenic On a scale of 1 to 4, ranked as 1 for slight health On a scale of 1 to 4, ranked as 1 for slight health
hazard because it can be a mild eye irritant (mucous hazard because it can be a mild eye irritant (mucous membrane irritation concentrate mist)membrane irritation concentrate mist)
No special ventilation is required during useNo special ventilation is required during use Meets EPA and OECD recommendations for ready Meets EPA and OECD recommendations for ready
biodegradability; practically non-toxic per EPA’s biodegradability; practically non-toxic per EPA’s aquatic toxicity scaleaquatic toxicity scale
Components on TSCA Chemical Substance InventoryComponents on TSCA Chemical Substance Inventory
DisinfectantsDisinfectants
Factors affecting disinfection processFactors affecting disinfection process TypeType ConcentrationConcentration TemperatureTemperature Contact TimeContact Time pHpH Presence of soil/organic matterPresence of soil/organic matter Number of organismsNumber of organisms Type and growth phase of organismType and growth phase of organism
IodophorIodophor
Broad spectrum Broad spectrum (inactivates IPNV)?(inactivates IPNV)?
NoNo
Inactivated by soil/organic Inactivated by soil/organic matter?matter?
Yes, but turns yellow & is more stable Yes, but turns yellow & is more stable than chlorinethan chlorine
Non-toxic fish?Non-toxic fish? Depends on dilutionDepends on dilution
Non-toxic humans?Non-toxic humans? Skin and eye irritationSkin and eye irritation
Corrosive?Corrosive? SlightlySlightly
Surfactant activity?Surfactant activity? NoNo
Leaves active residue?Leaves active residue? YesYes
Stable?Stable? Dissipates slowlyDissipates slowly
Tests for active chemical Tests for active chemical residues?residues?
Test stripsTest strips
Safe for environmentSafe for environment RegsRegs
Quaternary Ammonium Compounds Quaternary Ammonium Compounds (QACs)(QACs)
Broad spectrum Broad spectrum (inactivates IPNV)?(inactivates IPNV)?
NoNo
Inactivated by Inactivated by soil/organic matter?soil/organic matter?
Moderately stableModerately stable
Non-toxic fish?Non-toxic fish? Depends on dilutionDepends on dilution
Non-toxic humans?Non-toxic humans? Corrosive to skin and eyes; Irritation of Corrosive to skin and eyes; Irritation of respiratory tract; headache, drowsinessrespiratory tract; headache, drowsiness
Corrosive?Corrosive? NoNo
Surfactant activity?Surfactant activity? YesYes
Leaves active Leaves active residue?residue?
YesYes
Stable?Stable? YesYes
Tests for active Tests for active chemical residues?chemical residues?
Test stripsTest strips
Safe for environmentSafe for environment RegsRegs
Hypochlorite (HTH)Hypochlorite (HTH)Broad spectrum Broad spectrum (inactivates IPNV)?(inactivates IPNV)?
YesYes
Inactivated by Inactivated by soil/organic matter?soil/organic matter?
YesYes
Non-toxic fish?Non-toxic fish? Extremely toxic at low concentrationsExtremely toxic at low concentrations
Non-toxic humans?Non-toxic humans? Dust causes skin, eye, digestive tract and Dust causes skin, eye, digestive tract and respiratory burnsrespiratory burns
Corrosive?Corrosive? Yes, to metals and plasticsYes, to metals and plastics
Surfactant activity?Surfactant activity? V. slightV. slight
Leaves active residue?Leaves active residue? NoNo
Stable?Stable? No, dissipates rapidlyNo, dissipates rapidly
Tests for active Tests for active chemical residues?chemical residues?
Test stripsTest strips
Safe for environmentSafe for environment Regs (must be neutralized with sodium Regs (must be neutralized with sodium thiosulfate)thiosulfate)
Virkon-SVirkon-S(potassium monopersulfate)(potassium monopersulfate)
Broad spectrum Broad spectrum (inactivates IPNV)?(inactivates IPNV)?
YesYes
Inactivated by Inactivated by soil/organic matter?soil/organic matter?
??
Non-toxic fish?Non-toxic fish? Depends on dilutionDepends on dilution
Non-toxic humans?Non-toxic humans? As powder can be respiratory and eye As powder can be respiratory and eye irritantirritant
Corrosive?Corrosive? To metals but not nettingTo metals but not netting
Surfactant activity?Surfactant activity? Yes (including bacterial biofilms)Yes (including bacterial biofilms)
Leaves active residue?Leaves active residue? ??
Stable?Stable? Dissipates Dissipates veryvery slowly slowly
Tests for active Tests for active chemical residues?chemical residues?
??
Safe for environmentSafe for environment Regs., breaks down to harmless organic Regs., breaks down to harmless organic saltsalt
CullingCulling
An important strategy to reduce An important strategy to reduce transmission of pathogenstransmission of pathogens
Should include sick (as long as cause is Should include sick (as long as cause is infectious) as well as dead fishinfectious) as well as dead fish
Cull at least once per dayCull at least once per day Fish should be killed humanely, not Fish should be killed humanely, not
allowed to die from suffocationallowed to die from suffocation
Additional StrategiesAdditional Strategies
Changing flow to increase turnover Changing flow to increase turnover ratesrates
Density manipulationDensity manipulation
Culture ActivitiesCulture Activities
Minimize the number of different Minimize the number of different personnel working with a group of fishpersonnel working with a group of fish
Unaffected tanks should be worked on Unaffected tanks should be worked on before affected tanksbefore affected tanks
Care for young fish before older fishCare for young fish before older fish Equipment touching the floor should not Equipment touching the floor should not
contact fish culture watercontact fish culture water Fish that jump from tank to floor should Fish that jump from tank to floor should
be humanely killed, not returned to tankbe humanely killed, not returned to tank
III. Practices to Reduce III. Practices to Reduce Susceptibility to Infection and Susceptibility to Infection and
DiseaseDisease
Strategies for a Strong Immune Strategies for a Strong Immune SystemSystem
Optimum nutritionOptimum nutrition Fish should be from Fish should be from
optimum year class optimum year class brood stockbrood stock
Gentle handling to Gentle handling to reduce stress and reduce stress and injuryinjury
VaccinationVaccination
IV. MonitoringIV. Monitoring
Set up a Set up a monitoring and monitoring and response planresponse plan
Record KeepingRecord Keeping
Used to track changesUsed to track changes Used to improve biosecurity protocolsUsed to improve biosecurity protocols Includes water quality, feed fed, feed lot Includes water quality, feed fed, feed lot
numbers, visitors, number of dead and numbers, visitors, number of dead and culled fish, observations of abnormalities, culled fish, observations of abnormalities, laboratory results, results of treatmentlaboratory results, results of treatment
Monitor Water Quality!Monitor Water Quality!
Know normal vs. abnormal Know normal vs. abnormal behavioral and physical signs for behavioral and physical signs for
stress and illnessstress and illness
Behavioral and Physical Signs for Behavioral and Physical Signs for Stress/IllnessStress/Illness
MovementMovement Weak, erratic, lethargic swimmingWeak, erratic, lethargic swimming Abnormal reaction to external stimuli such as Abnormal reaction to external stimuli such as
noise or movementnoise or movement Scratching, flashing, rubbing against tank walls Scratching, flashing, rubbing against tank walls
or bottomor bottom Twitching, darting, spinning or jumping out of Twitching, darting, spinning or jumping out of
waterwater Crowding at inflent water supplyCrowding at inflent water supply Swimming upside downSwimming upside down Gasping at water surfaceGasping at water surface
Behavioral and Physical Signs for Behavioral and Physical Signs for Stress/IllnessStress/Illness
FeedingFeeding Not feedingNot feeding Reduced feeding (detected by system TAN Reduced feeding (detected by system TAN
and growth curves as well as observation)and growth curves as well as observation) BreathingBreathing
Decreased or increased rate of opercular Decreased or increased rate of opercular movementmovement
Behavioral and Physical Signs for Behavioral and Physical Signs for Stress/IllnessStress/Illness
Physical ConditionPhysical Condition Visible lesions or soresVisible lesions or sores Cloudy eyes, Cloudy eyes,
protruding eyesprotruding eyes GillsGills swollen, white, swollen, white,
pink or pale red, pink or pale red, eroded, puffy, bloody, eroded, puffy, bloody, brownbrown
Scale lossScale loss Swollen abdomenSwollen abdomen DiarrheaDiarrhea
Excess mucus on Excess mucus on skin/gills (check for skin/gills (check for excess mucus on tank excess mucus on tank screens)screens)
Spots, fungus on skinSpots, fungus on skin Unusual coloration on Unusual coloration on
body surfacebody surface Flared operculaFlared opercula Frayed fins or tailFrayed fins or tail Bubbles in eyes, skin, Bubbles in eyes, skin,
gillsgills
Submersible Biomass ScannerSubmersible Biomass Scanner
VAKI DNG VAKI DNG ((Kópavogur, IcelandKópavogur, Iceland))
Used to track Arctic char size & growth at CFFI.
V. DiagnosisV. Diagnosis
Supplies/Equipment for Fish Supplies/Equipment for Fish Health LaboratoryHealth Laboratory
Compound microscope (with 10X ocular Compound microscope (with 10X ocular and 4X, 10X, and 40X objectives)and 4X, 10X, and 40X objectives)
Slides, cover slipsSlides, cover slips Dissecting kit (for large and small fish)Dissecting kit (for large and small fish) Anesthetic (e.g., tricaine methane Anesthetic (e.g., tricaine methane
sulfonate (MS-222))sulfonate (MS-222))
DiagnosisDiagnosis
Keep accurate records so that an Keep accurate records so that an accurate history can be compiledaccurate history can be compiled
Learn normal and abnormal appearance Learn normal and abnormal appearance and behaviorand behavior
Evaluate water qualityEvaluate water quality Learn skin scrape and gill biopsy Learn skin scrape and gill biopsy
techniques to identify parasitestechniques to identify parasites Find an aquaculture veterinarianFind an aquaculture veterinarian
DiagnosisDiagnosis
An accurate diagnosis is essentialAn accurate diagnosis is essential Determines treatment regimen (whether, and Determines treatment regimen (whether, and
which, chemotherapeutants should be used)which, chemotherapeutants should be used) Treatment based on hunches results in Treatment based on hunches results in
wasted time and money and further wasted time and money and further degradation of the fishdegradation of the fish
Incorrect diagnosis prevents development of Incorrect diagnosis prevents development of an effective strategy to prevent recurrencean effective strategy to prevent recurrence
TreatmentTreatment Disease from water quality more likely in a Disease from water quality more likely in a
biosecure recirculating system (slow turnover biosecure recirculating system (slow turnover rate)rate)
If chemical treatment is necessary, effect on If chemical treatment is necessary, effect on biofilter must be considered (Table 13.3) (design biofilter must be considered (Table 13.3) (design system for biofilter bypass during treatment)system for biofilter bypass during treatment)
When treating the whole system, slow turnover When treating the whole system, slow turnover rate means chemical might need to be applied at rate means chemical might need to be applied at a lower concentration for a longer perioda lower concentration for a longer period
Take individual tanks off-line for bath or flow-Take individual tanks off-line for bath or flow-through treatment through treatment
Case Study #1Case Study #1
Recirculating salmonid facilityRecirculating salmonid facility Specific-pathogen-free eggsSpecific-pathogen-free eggs
Biosecurity recommendations included disinfection of Biosecurity recommendations included disinfection of eggs with iodophor upon arrival from suppliereggs with iodophor upon arrival from supplier
Specific-pathogen-free water supplySpecific-pathogen-free water supply Design criteria included clean outsDesign criteria included clean outs
Attention to biosecurity appeared to be Attention to biosecurity appeared to be excellent but after one year, saw system-wide excellent but after one year, saw system-wide fungal infections and upon routine inspection fungal infections and upon routine inspection fish were infected with fish were infected with Aeromonas Aeromonas salmonicidasalmonicida (furunculosis) (furunculosis)
Case Study #1 (cont.)Case Study #1 (cont.)
RecommendationsRecommendations Fungi growing on solids substrates, so system Fungi growing on solids substrates, so system
maintenance is overdue – it’s time to get into the maintenance is overdue – it’s time to get into the cleanouts and get the solids out of the system, also, use cleanouts and get the solids out of the system, also, use formalin to treat affected fish.formalin to treat affected fish.
Some of the clean outs were not installed, others were concreted Some of the clean outs were not installed, others were concreted in. As a result, needed to try to access the pipes from hard-to-in. As a result, needed to try to access the pipes from hard-to-reach areas – continually coping with chronic, low-level fungal reach areas – continually coping with chronic, low-level fungal infections in the system – install cleanouts after system builtinfections in the system – install cleanouts after system built
Regarding the furunculosis bacteria – recommendations Regarding the furunculosis bacteria – recommendations to disinfect eggs upon arrival were not followed because to disinfect eggs upon arrival were not followed because “the supplier disinfected them before shipping” – they are “the supplier disinfected them before shipping” – they are now disinfecting eggs upon arrivalnow disinfecting eggs upon arrival
Case Study #2 Case Study #2 (or, if we do everything you say, (or, if we do everything you say,
will we experience disease will we experience disease outbreaks?)outbreaks?)
FI research system – a biosecure systemFI research system – a biosecure system Spring water supplySpring water supply No infectious disease problems except No infectious disease problems except
chronic, recurring respiratory diseasechronic, recurring respiratory disease A “new” pathogen – chlamydia-like/rickettsia-A “new” pathogen – chlamydia-like/rickettsia-
like bacteria that infects gill cellslike bacteria that infects gill cells Identification of organism, development of Identification of organism, development of
prevention and control strategies are in prevention and control strategies are in progressprogress
Current/Future Issues in Current/Future Issues in Biosecurity of Recirculating Biosecurity of Recirculating
SystemsSystems The safety of “disease-free” ground water The safety of “disease-free” ground water
suppliessupplies Opportunistic pathogens present in Opportunistic pathogens present in
recirculating systems that come from the recirculating systems that come from the fish or from the environmentfish or from the environment
Biosecurity programs should be dynamic, re-evaluate and
change as necessary