Protecting Canada’s fish stocks

Ian Gardner

"The value of farmed fish and shellfish sales in Canada is about $1 billion per year," says Ian Gardner, Canada Excellence Research Chair in Aquatic Epidemiology at the University of Prince Edward Island (UPEI). "That’s a lot of seafood to oversee and keep free from disease. And the market is continually growing as the demand for sustainably produced fish, and seafood in general, increases."

The expansion of aquaculture—particularly in Canada, Europe and South America—has been associated with fish health and environmental concerns. One of these is an increase in sea lice infestations.

"I would say that control of sea lice is the main issue facing salmon aquaculture in Canada at the moment, and this will be one of our highest research priorities over the next seven years," says Gardner.

Sea lice are naturally occurring, minute parasites that attach themselves to the skin, fins and gills of both farmed and wild salmon. The lice feed on the skin of host fish, causing lesions that can affect the growth rate of infested fish and decrease their economic value. Once transferred to farmed salmon, the lice proliferate and, if untreated, can be transferred back to wild fish stocks.

"Part of the issue we are facing and trying to solve is how to make aquaculture systems sustainable while ensuring minimal transmission of disease between wild and farmed fish, and minimal consequences for the environment," says Gardner. "There is a lot of controversy about the effects of sea lice on wild salmon populations, especially in British Columbia."

With his colleagues at UPEI’s Atlantic Veterinary College, Gardner is developing management and intervention strategies in partnership with the aquaculture industry to ensure that consumers receive a healthy, safe product. His research will, in turn, contribute to how federal and provincial governments regulate fish farming. "The work will go towards helping inform policy," says Gardner.

Gardner’s program at UPEI will also feature strong collaboration with Norwegian researchers. He is in the process of setting up an exchange of doctoral and postdoctoral students with the Norwegian Veterinary Institute—a move he believes will contribute to increased knowledge sharing and a more holistic view of the issues facing the industry.

"We are going to be looking at emerging viruses from places like Norway and Chile, where there is a strong aquaculture presence, and developing systems for early detection and surveillance to protect the trade in salmon."

"These issues are not going away," he adds. "If we share information and collaborate internationally, it gives us a better chance of understanding the issues. Then, we can try and put strategies and policies in place to deal with them, along with whatever issues we meet in the future."