“Wild” salmon hatcheries under scrutiny
Canada: Inquiry into salmon returns to British Columbia rivers will receive a report on the potential of salmon produced in hatcheries and spawning channels spreading disease after being released into the wild
FishfarmingXpert, Odd Grydeland, April 12, 2011
Each year some five hundred million juvenile Pacific salmon are produced by government and private hatcheries and other salmon enhancement facilities. And while salmon farming companies have for some time now had to operate their hatcheries and farms based on an approved Fish Health Management Plan with the accompanying reporting and controls, none of the “wild” salmon production facilities have until recently been held under such scrutiny. Now that the federal government has taken over the responsibility for salmon aquaculture in B.C., this is about to change. All facilities will eventually need a licence to operate, and along with the licence comes a long list of conditions, such as a documented plan for ensuring good fish health and that sick fish are not released.
The Cohen Commission which is looking into the reason for a dismal return of sockeye salmon to the Fraser River in 2009 will receive its report on hatcheries and fish health in June, as Jennifer Allford of the University of Calgary reports;
Dr. Craig Stephen, professor of ecosystem health in veterinary medicine faculty, is studying whether salmon from public hatcheries are potentially spreading disease to sockeye salmon in B.C.’s Fraser River, contributing to their decline. Stephen and his colleagues at the Centre for Coastal Health—a research network that works to identify and understand the interactions of human, animal and environmental health—will submit a scientific report to the Cohen Commission, the federal panel that’s exploring the decline of sockeye salmon in the Fraser River.
The vast majority of wild salmon in the Pacific Ocean begins life in one of dozens of public enhancement hatcheries in rivers on the west coast, says Stephen. “Most salmon losses occur between the time an egg is laid and the young fish head to the ocean. Hatcheries grow these young fish to help to reduce those losses, putting more fish out to sea. We let them go out to the wild, then they spawn back at the hatchery and keep that cycle going.”
While these public hatcheries—regulated by the Department of Fisheries and Ocean—have been putting salmon into the Pacific Ocean for a hundred years or more, in recent decades the practice has started to come under scientific scrutiny. “When you have fish from hatcheries interacting with truly wild fish in the ocean, there are genetic concerns, there are mixed fish stock concerns, there are competition concerns, and for us, what we’re looking at are disease concerns,” says Stephen. “Most of the work has been done on the genetic issue and the mixed stock fishery; nobody has really looked at this question of disease transmission yet.”
Stephen and his Centre for Coastal Health colleagues will review the scientific literature, gather data on historical health records from enhancement hatcheries, spawning channels and community hatcheries, in order to do a risk assessment on what kind of pathogens exist and how often they emerge. Finally, they will review the hatcheries’ policies and practices to see whether they are preventing, mitigating or controlling these risks.
The Hatchery Disease Impact Assessment will be submitted in June—one of 13 different scientific reports that examine environmental changes along the Fraser River, marine environmental conditions, aquaculture, predators, diseases, water temperature and other factors. The Cohen Commission will develop recommendations for improving the sustainability of the sockeye salmon fishery in the Fraser River. Its final report to the federal government will be delivered June 2012.
