If it’s working well in Norway, maybe it will work well here. That’s what Dr. Shannon Balfry thinks about using “cleaner” fish to control the issue of sea lice at salmon farms off our coast. The head of fish propagation research at the Vancouver Aquarium Marine Science Centre just returned from the Scandinavian country where she visited a salmon farm that’s using lumpfish to clean sea lice off their salmon. She also toured a lumpfish production facility and Norway’s Sea Lice Research Centre.
Sea lice are a major pathogen affecting the global salmon farming industry. While sea lice are not dangerous to humans, they can create open lesions in salmon and make them susceptible to disease. Additionally, they can infect wild salmon migrating past the pens.
While the research into “cleaner” fish is just ramping up now, the idea to do it came about last spring. The focus then was to see if local cleaner fish – different species of perch – would eat sea lice to begin with. (They are known to eat parasites off larger fish in the wild.) This first step of the research went well; Shannon found that kelp perch (Brachyistius frenatus) “love” sea lice.
Now, with sea lice eggs from the Centre for Aquatic Health Sciences on Vancouver Island, Shannon and her team are ready for the next stage: seeing if the perch will pick sea lice off Atlantic salmon and eat them. First, they have to give the sea lice some time to settle on host salmon before they put the perch in. Next, one group of salmon will be joined by kelp perch, another group by pile perch (Rhacochilus vacca) and the last group will not have any perch with it (serving as the control group).
“Then, we wait and see what happens,” says Shannon. She says they plan to compare the cleaning activities of these two perch species, taking into consideration their different sizes and their cleaning preferences (i.e. whether they prefer to eat sea lice at a particular size, life stage, location on the salmon, etc.).
The results won’t be known until the end of May, but Shannon is excited already. “I keep lifting the top and peaking, even though things have to be kept dark for the sea lice,” she says.
The research is taking place at the Centre for Aquaculture and Environmental Research in collaboration with Fisheries and Oceans Canada and Marine Harvest, the largest producer of Atlantic salmon in British Columbia. Salmon farmers are especially interested to see how this research turns out because it means they could potentially phase out the use of chemical treatments.
Shannon says, “There is a lot of buzz from the B.C. salmon farming industry to see if this will work in the lab. And if it does, the research will continue with field trials.”
We’ll have an update for you this summer.
Written by Karen Glanzberg, content writer/editor at the Vancouver Aquarium Marine Science Centre.