Government report says ‘farms not to blame’ for sea lice spread

Salmon farms are not responsible for spreading sea lice among the wild fish population, according to a new report from the Canadian government’s scientific advisors, and British Columbia’s farmers have welcomed the findings.

The peer-reviewed Science Response Report, Association between sea lice from Atlantic salmon farms and sea lice infestations on wild juvenile Pacific salmon in British Columbia, was published on the Department of Fisheries and Oceans Canada’s (DFO) website by the Canadian Science Advisory Secretariat (CSAS).

The aim of the study was:

1. to estimate the number of Lepeophtheirus salmonis copepodids (the infective sea lice larval stage) produced by Atlantic salmon farms in British Columbia;
2. to summarise counts of sea lice numbers on wild juvenile Pacific Salmon; and
3. to determine the statistical link between sea lice infestations on Atlantic salmon farms and prevalence on wild juvenile Pacific salmon populations in British Columbia.

It concludes: “No statistically significant association was observed between infestation pressure attributable to Atlantic salmon farms and the probability of L. salmonis infestations on wild juvenile Chum and Pink salmon in Clayoquot Sound, Quatsino Sound, Discovery Islands, and Broughton Archipelago. The lack of statistical significance implies that the occurrence of L. salmonis infestation on wild migrating juvenile Pacific salmon cannot be explained solely by infestation pressure from farm-sourced copepodids.”

The report also concludes, however, that sea lice numbers are on the rise in all the areas studied.

Brian Kingzett, Executive Director of the BC Salmon Farmers Association (BCSFA), said: “As a sector, we continue to improve and innovate to ensure that our operations have minimal impact on the surrounding ecosystem. As farmers, and as British Columbians, we care about wild salmon and agree whole heartedly with DFO [Department of Fisheries and Oceans] Minister Joyce Murray regarding ensuring the protection of wild Pacific salmon.”

The BCSFA said its members are committed to the continuation of monitoring sea lice on wild salmon in all operating areas as a condition of federal licensing for Atlantic salmon farms.

It pledged that the sector will continually strive through innovation and Indigenous oversight to lower sea lice levels on farms and build on the results reflected in this recent CSAS review, to show that farmed and wild salmon can coexist sustainably.

In 2020, Joyce Murray’s predecessor as Fisheries Minister, Bernadette Jordan, ordered the closure of all net-pen fish farms in the Discovery Islands region of British Columbia, and Canada’s federal government is consulting on a “transition plan” to end all net-pen farming by the end of 2024.

The argument that salmon farms endanger wild fish by allowing sea lice numbers to multiply is one of the principal reasons given by campaigners for shutting down the net-pen sector.

Brian Kingzett