New Research Suggests Local Perch Species Could Control Sea Lice in Aquaculture

Vancouver, BC – They might be tiny, but sea lice remain one of the biggest challenges facing the salmon aquaculture industry. The copepods — which are found naturally in the ocean — parasitize both farmed and wild fish populations. Concerns have been raised that sea lice from farms cause additional infection to wild fish. To help address the risk, farmers are exploring natural means of managing sea lice on their fish, rather than using costly chemical and medicinal treatments.

New research started at the Vancouver Aquarium Marine Science Centre suggests that local B.C. perch species are effective in picking sea lice from salmon. The use of one kind of fish to “clean” another is a proven method of managing sea lice in salmon culture in Norway. “Sea lice have been identified as an issue of public concern, and while they are naturally occurring in the environment, through regulation they must be controlled on salmon farms,” said Dr. Shannon Balfry, who led the research project. “We have an opportunity with this research to try and address it in an environmentally friendly manner.”

This research is the first of its kind in B.C., said Balfry, and the results appear promising. Several preliminary trials — conducted at the Fisheries and Oceans Canada (DFO) Centre for Aquaculture and Environmental Research — determined that both kelp perch and pile perch will clean sea lice off experimentally infested salmon. Researchers looked at differences in cleaning activity between the two species of perch and in different sizes of the perch, and at cleaning preferences in terms of sea lice life history, location of sea lice on salmon, and behavior of cleaning in the lab.

The initial research was a collaborative project by the Vancouver Aquarium, Fisheries and Oceans Canada, and Marine Harvest Canada. It was funded by grants from the BC Salmon Farmers Association, Marine Environmental Research Program, and seafood sustainability organization Sea Pact, which is providing continued funding for further research in 2017.

“The results appear promising, but there’s more research to be done,” said Dr. John Nightingale, CEO of the Aquarium. “We hope the use of perch becomes a viable tool for reducing the risk of sea lice infestations in wild salmon in B.C.”

Vancouver Aquarium Marine Science Centre
The Vancouver Aquarium Marine Science Centre is a non-profit society dedicated to the conservation of aquatic life.

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April Penney
Ocean Wise