Principles of Genetics and Breeding

15.1.9. General principles of quarantine

The following general principles for the use of quarantine for aquatic animals are taken mainly from FAO (2007):

• Where risk analysis has shown that the level of risk posed by the proposed importation of a consignment of live aquatic animals is unacceptable, quarantine is one of a number of potential risk mitigation measures that singly or in combination with other measures, can be considered to reduce the risk to within the national appropriate level of protection (ALOP).

• The stringency of quarantine applied should be commensurate with the estimated level of risk, which is a function of the source and destination of the aquatic animal movement.

Importations of exotic species for aquaculture development and those originating from wild populations or other sources of unknown or poorly documented health status will often require stringent quarantine measures.

For the first movement (introduction) of an exotic species, the use of protocols outlined by the International Council for the Exploration of the Sea (ICES, 2005) and the European Inland Fisheries Advisory Commission (EIFAC) (Turner, 1988) is strongly recommended.

Because transmission of pathogens can occur across major taxonomic groups of aquatic animals, countries should avoid making scientifically unsound, arbitrary distinctions between marine and freshwater species, or between wild, cultured or ornamental species, with respect to the risk posed and the level of quarantine needed.

Because it is extremely difficult and often impossible to eradicate aquatic animal diseases once established in the environment, particular care should be taken over introductions intended for release into natural waters.

Quarantine procedures, including observation for clinical signs of disease and diagnostic testing, can be conducted in the country of origin, in a country of transit and/or in the receiving country.

Quarantine facilities should meet minimum standards for location, design, infrastructure and equipment, physical security, treatment of intake and discharge waters, staff expertise and training and operating protocols to ensure their effective operation and that aquatic animals and any pathogens they may carry will not escape into the surrounding environment. Countries may need to develop such standards.

Movements involving a high or unknown health risk (e.g. from areas where exotic diseases are known to occur) should only take place where full containment facilities and support services (diagnostics capability, security, inspection) are in place. Where facilities do not currently meet these requirements, only low risk movements should be approved.

Disinfectants, antibiotics and other chemicals and drugs for use in quarantine facilities should be chosen and applied in conformation with local laws and regulations and in a manner that ensures the protection of personnel, the aquatic animals being held and the external environment from their possible harmful effects.

A wide range of products and procedures can be applied in the cleaning and disinfection of quarantine facilities. Competent Authorities should evaluate the effectiveness of such products and procedures against relevant pathogens under local conditions. Decisions on which products to use should take into account their legality, microbiocidal efficacy and their safety for personnel, aquatic animals and the environment. Approved procedures (SOPs) for the use of disinfectants should be established.

All effluent and wastes generated by a Quarantine Facility should be treated in a manner that effectively destroys all pathogens. To ensure continuous operation and complete containment, quarantine effluent systems should equipped with fail-safe backup systems. As treated effluent and waste may contain substances deleterious to the environment (e.g. active disinfectants), they should only be disposed of in a manner that minimizes environmental impact. Where possible, countries should reduce the level of risk involved by importing eggs, embryonic or juvenile stages, as these generally carry fewer subclinical infections than do adult animals and are often easier than adults to maintain under quarantine conditions.

When possible, candidate stocks for introduction or transfer should be moved on a batch-by-batch basis, a batch being a group of animals of the same age, from the same population and maintained as a discrete group on the same water source. Mixing of animals, water or equipment between batches should not occur.

Co-habitation experiments in which key native species are held in contact with the exotic species or effluent waters from the quarantine holding tank can be performed to investigate pathogen presence in imported aquatic animals and the susceptibility of native species (however, note that negative results do not demonstrate an absence of pathogens). Placing quarantined animals under increased stress may also assist in the overt expression of subclinical infections.

Many diseases, especially those caused by external parasites, can be treated. However, because chemical therapy can cause additional health complications, such as the development of antibiotic-resistant strains of bacteria, it should be used responsibly, with due caution and expert advice.

As many treatments, such as those for monogenean gill parasites, are often only partially effective, it is critical to ensure that the pathogen is eliminated and that subclinical infections do not occur.

Should a serious untreatable disease or pathogen be encountered in aquatic animals held in quarantine, the entire stock should be destroyed and the facility appropriately disinfected.

Introductions from sources that have passed a quarantine containment process may receive “approval” status if conditions do not change at the export site, further reducing quarantine requirements/duration.

At the national level, the following necessary supporting services must also be in place for effective quarantine to occur:

• adequate legislation;

• effective enforcement (e.g., border customs and inspection, post-border follow up);

• knowledgeable and supportive aquaculture industry;

• sufficient political will;

• competent and readily available diagnostics support;

• existence of reliable diagnostics tests for major pathogens;

• good working relationships between importing and exporting country CAs;

• good knowledge base of pathogens present in the exporting and importing countries (surveillance and monitoring, disease surveys); and

• good information base on pathogen biology, prevention, treatment, etc.

Quarantine, particularly of exotic species, can be an expensive activity. Responsibility for the costs of operating a Quarantine Facility and other related financial issues (e.g. costs of permits, supervision, diagnostic and other services, treatments, loss of stock due to mortality or their ordered destruction, etc.) should be clearly spelled out to all parties via legal documentation. Generally, the importer of a consignment of live aquatic animals should bear all costs associated with complying with the aquatic animal import standards.

Allowable limits of Heavy metals in shrimp hatchery system

Arsenic	76ppm/L
Cadmium	3ppm/L
Chromium	12 ppm/L
Lead	1.5 ppm/L
Nickel	70 ppm/L
Methyl Mercury	1 ppm/L

Water Quality criteria during packing of post larvae of shrimp

Variable	units Values
pH	6-7.5
TDS mg/L	50mg or Less
Soluble phosphorus	0.5 mg or Less
BOD (mg/L)	50 or Less
DO (mg/L)	4

Seeds shall be certified based on the following criteria

• Pathogen free
• No discolouration
• No tail cut or Antenna cut
• The gut should be filled up
  
• Seeds will be active in the bowl text
  
• Seed shall not have any anti biotic residues such as chloramphenicol , nitro furan more than the allowable limit
• Chloramphenicol can cause fatal aplastic anemia and nitrofuran are
  
• carcinogens
  
• Stress tests against formalin, salinity should be conducted for shorter
  
• period of time.
• Seeds shall not have moulting stage, 10% may be allowed.
• Test for MBV and WSSV should be negative
• Seeds shall not have any parasites.
• Seeds shall have
  
• aldrin/dialdrin, chlordane 0.3 ppm/L
• DDT, TDE, DDE 0.5 ppm/L
• Diquat 3 ppm/L
• Heptachlor 0.3 ppm/L
• Mirex 0.1 ppm/L
• PCB 2.0 ppm/L