FACT SHEET - AQUATIC ANIMAL HEALTH – DISEASE PREVENTION

Canada’s reputation for high quality fish and seafood depends on keeping our wild and farmed aquatic animals protected against serious infectious diseases.

Fisheries and Oceans Canada (DFO) works with the Canadian Food Inspection Agency’s (CFIA) to deliver the National Aquatic Animal Health Program (NAAHP). The NAAHP improves protection of Canadian aquaculture and wild fisheries from diseases of concern to maintain the country’s competitive access to seafood trade markets. The NAAHP will complement measures already in place – on the farm and through provincial aquatic animal health management programs.

The Evolution of Aquatic Animal Health Management

National attention to aquatic animal health has grown quickly over the last decade due to an increase in volume and diversity of live and fresh seafood trade around the world. Live fish can now travel as rapidly as people between countries to reach consumer markets as well as for aquaculture production. The World Organization for Animal Health (the Office International des Épizooties – OIE), a veterinary organization responsible for setting standards for land-based and aquatic animal health management programs, has stringent guidelines to reduce the risk of transfer of serious disease with the movement of live aquatic animals or seafood products.

These developments have occurred over the last 30 years – in parallel with the development of the aquaculture industry. As with any other animal or plant food producing system, fish and shellfish farmers need to pay close attention to their stocks for signs of any disease that could impact productivity and the aquatic environment.

Infectious agents, naturally-occurring viral or bacterial diseases, can spread through water and do not distinguish between cultured and wild aquatic organisms. Direct observation to detect disease is difficult to do for submerged animals like fish and shellfish. This means that wild and farmed aquatic animals have a greater opportunity to exchange diseases and emerging disease situations can take more time to detect, than is the case for many diseases that affect their land-raised counterparts.

Disease control measures

For infections that emerge in aquaculture stocks that come from the environment and/or surrounding wild aquatic animals, farmers can take a number of measures to manage the impact on healthy stocks, including:

• improved nutrition and diet, principally for finfish, to help them resist infections – just like people take Vitamin C to boost resistance to colds;
• controlled water source and quality to ensure optimum growing conditions and reduce exposure to infectious agents;
• maintaining stocking densities at levels that optimize growth and avoid overcrowding that reduces the ability for the animal to resist infection;
• vaccination (where available) to help juvenile finfish fight local viral or bacterial infections; and,
• close monitoring of stocks to ensure early detection of disease problems by aquatic animal health professionals.

For infections that come from human activities such as stock transfers or the import of broodstock, shellfish seed, and smolt (juvenile fish), farm operators as well as local and national authorities can take a number of additional measures to reduce the risk of exposure to, or impact on, healthy aquatic animal populations:

• screen fish broodstock and shellfish seedstock for diseases not present in the importing waters;
• restrict imports to stock that meet international trade certification requirements; and,
• undertake official surveillance programs to support certification of stocks destined for export per the requirements of the importing country..

Disease control methods

Farm fish and shellfish can be inspected and be certified free of any diseases that are a threat to aquatic animals before they are placed in the marine or freshwater environment. This can be done at a national level, per OIE guidelines, or at a provincial level for diseases that do not pose a threat to native, wild stocks or trade.

Farmed juvenile salmon and trout can be vaccinated against some diseases they are likely to encounter when they leave the hatchery. The treated fish are monitored throughout their entire life cycle by trained professionals, such as aquatic veterinarians. Some provinces can order isolation measures to reduce the risk of disease spread. These measures can include de-populating the stock and implementing vigorous disinfection procedures to remove the infection from a facility and reduce the risk of spread to neighbouring farms or the surrounding environment. Such drastic measures are usually reserved for serious diseases where there is a good chance of successful of removing the infectious agent.

Health Canada has regulations that control the use of medications used in the production of food, including farmed fish and seafood. If any veterinary drugs are used, their administration must follow rules designed for effective, environmentally responsible and safe application to seafood.

Integrated approach to health management

DFO works closely with the CFIA, industry, universities, other federal departments and the provinces to coordinate Canada’s aquatic animal health programs, which span federal and provincial regulatory responsibilities, as well as aquaculture industry good management practices.

Good farm management practices benefit the aquaculture operator in levels of production and seafood quality. It also benefits the provincial and federal authorities responsible for health management, as the farmers grow stock that have a healthy start in life, making them less vulnerable to local health challenges.

Provinces with strong aquatic animal health programs aimed at early intervention and effective control measures for recurrent disease problems gain stable levels of productivity and a reputation for quality and sustainable aquaculture management. This applies mainly to coastal provinces. Québec and Alberta, provinces where there is significant freshwater aquaculture activity, are developing programs aimed at supporting their aquaculture development.

At the federal level, good management practices on the farm complemented by provincial programs help Canada’s ability to certify fish and seafood products destined for export. The federal government must undertake surveillance for diseases to prove that Canadian product is free from disease, per international standards. This surveillance is assisted by control of introductions and transfers using Canada’s National Code on Introductions and Transfers of Aquatic Organisms which is co-managed by DFO and the provinces.

This integrated approach to aquatic animal health protects the health of Canada’s aquatic resources, wild and farmed, and provides greater economic stability and potential for growth for the industries and regions that depend on these resources. The bottom line is a healthy and sustainable supply of high quality seafood for Canadians and our export markets.

For further federal information visit the following web sites:

Fisheries and Oceans – Aquatic Animal Health Information:
http://www.dfo-mpo.gc.ca/science/aquaculture/aah_e.htm

Canadian Food Inspection Agency’s National Aquatic Animal Health Program: http://www.inspection.gc.ca/english/direct/naahp

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Last Updated : 2006-06-28

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