Management of Fish Health in BC

• Fish Health Advisory Committee
• Fish Health Management Plans and Guidelines
• Bio-security Procedures for Fisheries Inspection of Marine Fish Farms
• Fish Health 2003-2005.pdf
• Fish Health Report 2006 pdf
• Fish Health Report Oct 2006.ppt.ppt
• News Release  December 2006.pdf

Maintaining healthy stock is essential to profitable farming.  Managing to promote fish health is not simply managing disease but involves management of all aspects of farm production that can impact on fish health, growth and survival. Nutrition, feed quality and feeding techniques, water quality, handling, grading, vaccination, broodstock management and disease screening are part of an integrated fish health management program.

As in other agri-food industries, veterinarians and fish health professionals are involved in the day-to-day management of fish health in the aquaculture industry. Fish are observed on a daily basis and records are kept of their behaviour, feeding activity, and general physical condition. If a health or disease problem does arise, the fish health professional staff make the necessary changes to deal with the problem in an efficient and effective manner.

Diseases of Concern: Health Management and Disease Management Measures

The same diseases that can affect farmed salmon are also found in wild salmon stocks. In most instances these diseases are managed on farms by private fish health professionals and pose a low risk to wild stocks.

However, susceptibility to disease varies between strains of salmon (wild and farmed alike), types of disease agents and on the specific health status of the stock. For farmed salmon, specific disease agents of concern have been identified, such as Infectious Hematopoietic Necrosis virus (IHNV), because of their impact on fish health and survival.  In such cases additional measures to manage and control disease are required.

MAL fish health staff routinely inspect salmon farms for health assessment. Also, when unusual fish health problems or diseases of concern occur in salmon farms, MAL fish health staff will investigate and collect samples to determine the cause of the losses. They may also visit other fish farms in the same area or those that are believed to be at risk to assess their health status and test for the presence of specific disease agents. Samples are submitted to the Ministry's Animal Health Laboratory for analysis and confirmation of a specific diagnosis.

Farms affected by diseases of concern such as IHN must immediately implement isolation measures to reduce the impact of the disease. Some measures include:

• Enforcing strict disinfection procedures
• Limiting the movement of all personnel, equipment and boats
• Using separate dive teams to survey sites at each farm
• Special procedures for removal and disposal of dead fish
• Special precautions for harvesting to prevent spread of the disease

The Growth of Fish Farming

There has been no increase in disease outbreaks as a result of the growth of fish farming. Rather, improved farming techniques, such as better vaccines, have reduced the loss of fish to disease in salmon farms. The province conducts fish health surveillance of farmed stocks on a routine basis and monitors the changing health status of farmed fish stocks.

Fish Diseases Transferred to Humans

Salmon are cold-blooded animals that live in a very different environment than humans. There are very few fish pathogens from temperate ocean waters that can cause diseases in humans, and many organisms of fish origin have a limited ability to survive in humans (Stephen & Iwama, 1997).

Updated:  December 9, 2003