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CV MohanNACA

Aquaculture will intensify, diversify, and expandProduction of all species groups (includingProduction of all species groups (including seaweeds) will be increasedNew species will appear (exotics, e.g. P.vannamei?)All environments will be increasingly utilizedIncreasing influence of markets, trade and consumption (food safety)More and more resources will be used in increasing quantitiesDrive towards enhanced regulation and better governance

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Each of the trends will have good and bad impactsHow to promote the good impacts and mitigate the bad impacts … the challengeThis will create a ….……drive for better management……And this will put ……

considerable pressure on the farmer and…….considerable pressure on the farmer and the national governments

Major concerns will remain same!◦ Food safety issues (e.g. antibiotics)◦ Pathogen introduction and spread ◦ Exotic species introduction ◦ Fish meal and trash fish utilization for aquaculture ◦ Wetland and habitat utilisation◦ Abstraction of water and Ground water contamination◦ Sediment deposition, effluent discharge and eutrophication◦ Wildlife and biodiversity◦ Social issues related to resource utilization and access◦ Dependence on wild based fisheries for feed and seed◦ Small-scale farmers (the trend is consolidation and (

integration)

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Intensification of aquaculture practices have given rise to emergence of several serious g gdiseases (e.g. WSD, TS, IMN, EUS, KHVD)International trade of live aquatic animals and their products responsible for spread of pathogens

Disease related loss impacting livelihood of farmers and national economies ($ 3 billion per year)year)International spread of pathogens associated with movement of aquatic animals Establishment of exotic pathogens is a major concernImpact of pathogens on biodiversity (e.g. EUS and snakeheads)Misuse of chemicals in the name of treatment suse o c e ca s t e a e o t eat e tleading to food safety issues and trade restrictions

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Fish◦ Epizootic ulcerative syndrome◦ koi herpes virus disease

l◦ Viral nervous necrosis◦ Grouper iridoviral diseaseShrimp◦ White spot disease◦ Taura syndrome◦ IMNPrawn◦ White tail disease (MrNV)Lobster◦ Milky lobster diseaseMollusc◦ Abalone viral mortality

Crustaceans◦ Monodon Slow growth syndrome (MSGS)

tegumental gland associated virus (TGAV) ??◦ Loose Shell syndrome in P monodon◦ Loose Shell syndrome in P.monodon◦ bamboo shrimp syndrome in P.vannamei Finfish◦ Edwardsiella tarda in marine species◦ BB” or big belly (new Vibrio species??)◦ Streptococcus dysgalactiae◦ Streptococcus iniae in marine and also freshwater species◦ Tenacibaculum maritimum in marine species◦ Francisella sp in Tilapia in Indonesia◦ Streptococcal diseases in freshwater species

Red spot disease in grass carp (GCRV)◦ Red spot disease in grass carp (GCRV)◦ Red spot disease in Tilapia?? Mollusk◦ Babylonia Mortality ◦ Ganglioneuritis in abalone

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◦ Establishing practical national disease control programsNeed for increased Government investment in diagnosis, capacity building, surveillance and g , p y g,reporting, quarantine, import risk analysis, etc

◦ Responding to increasing influence of markets, trade and consumption

Trade issues on food safety grounds (e.g. antibiotics, malachite green) Trade issues on account of presence of pathogens in live animals and their products (e.g. harvested shrimp) Certification and traceability requirements

◦ Preparing for enhanced regulation and better governance Need for Better compliance to International (OIE) standards and guidelines

Aquaculture will diversify, expand and intensify and disease risk will increaseT d ( t f li i l d th iTrade (movement of live animals and their products) will happen and diseases will spreadEliminating risk is impossible, so risk reduction should be the strategyRisk reduction = Health Management = Bio-securityBio security Development and Implementation of strategies/tools/practices to manage risks is a shared responsibility

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Guidance tools◦ Standards and agreements (WTO-SPS, OIE Aquatic Code)◦ Regional Technical GuidelinesRegional Technical Guidelines ◦ Standard operating procedures◦ Better management practices (BMP, GAP)Implementation tools◦ Diagnostics◦ Risk analysis ◦ Health certification ◦ Quarantine◦ Surveillance and disease reporting◦ Surveillance and disease reporting◦ Contingency planning◦ Disease control strategies

It is a very broad concept. ◦ Not same as use of chemicals and health

dproductsit involves understanding and managing the environment, host and the pathogenshould be applied at all levels◦ Hatchery/pond/farm/processor levels◦ village/district level◦ national level◦ Regional level◦ international level

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Bio-security is a new term for an old concept. There is no single definition for bio-security. e e s o s g e de t o o b o secu tyHowever, bio-security can be defined as a set of standard scientific measures, adopted to exclude pathogens from the country (national level bio-security) and from culture environment and host (farm level bio-

i ) d b dl li i hsecurity) and, more broadly, to limit pathogen establishment and spread

National level◦ National aquatic animal health strategies/bio-security

plansplans◦ Several components (dealt separately) Farm level◦ identification of pathogen entry routes◦ quarantine and screening of hosts introduced in the

system◦ disinfection at defined critical control point

restricted access◦ restricted access◦ identification of risk factors which favour pathogen

establishment and spread◦ Etc, etc……

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Host-pathogen-environment interactionsEntry, establishment and proliferation of the

th i th h t t t tipathogen in the host target tissuePathological changes in the target tissueFunctional failure of target tissueClinical manifestation (disease expression)morbidityMortality

tb koutbreak

pathogen

host

Pathogenicitymechanisms

environment

Disease resistance Target tissue

pathologymechanisms

Disease inanimal

Function failureClinical signs

mortality

Mechanismsof spread within a

pondTIME

Outbreak ina pond

Epizootic in aarea

p

Mechanisms ofSpread between

ponds

Spread betweenanimals

Spread between ponds

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Clinical signs are non-specificSimilar clinical signs for different diseases (need for differential diagnosis)for differential diagnosis)Functional failure of target tissue is reflected in the form of clinical signsGood relationship between pathology and clinical signs (examples)case history + clinical signs are very useful for presumptive diagnosis Some examplesSome examples◦ Swimming at the surface, gasping, congregating at

inlets/outlets, ulcers and hemorrhages on body, torn fins, gill rot, fin rot, dropsy, not feeding, slow growth, erratic swimming, etc

Sub-clinical infectionClinical infectionC ca ect oMorbidityMortalityPond outbreakEpizootic (epidemic)Panzootic (pandemic)Panzootic (pandemic)

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National bio-security plan or national aquatic animal health strategies◦ Competent Authority◦ Legislative support◦ National advisory committee◦ National list of diseases◦ National surveillance system◦ Disease reporting◦ Emergency preparedness and contingency planning◦ Emergency preparedness and contingency planning◦ Quarantine and health certification◦ Import risk analysis◦ zoning

Sets of standard practice that will reduce the probability of pathogen introduction to the culture system, its amplification in the culture environment and cultured host leading to disease outbreak and subsequent spread. To achieve, fool proof bio-security, it is necessary to understand all the routes by which the pathogen gains entry into culture units and p g g ythe farm level component causes (risk factors) which favor its amplification to levels sufficient to cause disease outbreaks (risk analysis).

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Possible pathogen carriers include ◦ infected hosts (e.g. seed, brood-g

stock, vectors, intermediate hosts, reservoir hosts), ◦ non-host biological carriers (e.g.

birds, dogs, insects, other predators, human beings) ◦ and fomites (e.g.

water, vehicles, buckets, shoes, nets, clothing). Routes of entry◦ Pathogen carriers could enter the culture system

through waterborne, airborne and overland transport routes.

waterborne route◦ (a) site selection to avoid contaminated sources◦ (b) water use reduction, (c) closed systems◦ (d) water treatment(d) water treatment◦ (e) screens and filters at water intake point◦ (f) use of disinfectants, (g) reservoirs◦ and (h) switching over to ground water and subsurface wells. airborne route ◦ (a) siting the farm away from other farms and aquaculture waste dumps◦ (b) placing covers over the ponds◦ (c) indoor rearing,◦ (d) bird deterrence programme, (e) control of insects. Overland ◦ (a) screening of hosts used for culture

(b) l d b ll f◦ (b) placing restrictions on visits and access by installing perimeter fencing◦ (c) adopting strict sanitary measures for visitors, farm staff (foot dips, hand hygiene,

protective clothing) and vehicles (wheel dips)◦ (d) placing restriction on movement of farm tools and equipment (nets, buckets,

aerators, etc), ◦ (e) by restriction on movement of cultured organism between ponds and farms.

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can be very expensive may not be feasible in open farming systemsay ot be eas b e ope a g syste sIdentification and quantification of relative risks associated with different pathogen carriers and routes of entry (epidemiological studies) would help to target resources to the main risksBio-security measures should be cost effective if it has to be adopted by small scale farmers

System specific and cost-effective, better management practices (BMPs) incorporating g p p gprinciples of bio-security should be developed, demonstrated and validatedCommodity specific BMP programs are becoming popular in many countries of the region

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Prevent entry ofpathogens

Prevent diseasedevelopment in animals

better management practicesFarm level Bio-security

Risk assessment and management

National strategies/bio-security plans

Prevent spread between animals in pond

Prevent spread between

Prevent nationalentry and spread

National strategies/bio security plansRegional initiatives

International initiatives

Prevent spread between ponds

Prevent spread between farms in the area

Prevent regional spread

Prevent internationalspread

host Watersoil

Risk managementGood husbandry

Seed quality (screening)Size at stockingSPF/SPR stocks

Stocking densityNutrition

Vaccinationimmunostimulants

Water qualityPond soil quality

Good pond bottomFeed management

Bloom managementimmunostimulants

Better management practices (BMPs)

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Minimise the risk of pathogen entry

Mi i i th i k f di d l t

ADOPT BMPs

Minimise the risk of disease development

Minimise the risk of pond outbreak

Minimise the risk of epizootics

Minimise the risk of national spread

IMPOSSIBLE TO ELIMINATE RISK OF DISEASE IN AQUACULTURE