Exciting research into sea lice resistance in coho salmon

November 8, 2016 - Campbell River, B.C.

A team of researchers on Prince Edward Island are mapping the pathways of lice resistance in a project that could shift the paradigm for Atlantic salmon and aquaculture.

Dr. Laura Braden, a post-doctoral fellow in the Pathology & Microbiology Department at the Atlantic Veterinary College, is leading the research along with Department of Fisheries & Oceans and the Centre for Aquaculture Technologies.

In 2015, Dr. Braden’s team flew 600 coho salmon from Vancouver Island to labs at Prince Edward Island, where they studied the rejection of sea lice at a molecular level.

“For Atlantic salmon, lice infection can cause considerable damage to the skin, which can lead to many issues, including secondary disease,” Dr. Braden explains. “But we don’t see the same response in resistant species, like coho.”

Other types of Pacific salmon have some resistance to sea lice, but none are as pronounced as the coho.

“Pink salmon also reject the parasite but I’ve never seen a rapid tissue response like this before,” Dr. Braden says.

Initial results demonstrate how juvenile Pacific coho salmon exposed to salmon lice are able to rapidly reject the parasite, with virtually no lice remaining on the fish after 10 days.

And their results suggest that the fish do not simply reject the louse, but actually might be killing them.

“It is absolutely incredible, these fish are very small and we challenge them with a lot of lice, but it doesn’t matter. Whatever mechanism is responsible for this response is extremely effective,” Dr. Braden says.

coho sea lice