A recent report examining the dynamics between wild juvenile Pacific salmon and sea lice infestation levels in Clayoquot Sound adds fodder to the push to remove open-net pen salmon farms to help rebuild wild salmon stocks.
But its conclusions are being disputed by the industry.
Mack Bartlett is the lead researcher for the Juvenile Salmon and Sea Lice Monitoring in Clayoquot Sound project run out of the Cedar Coast Field Station, an area research centre funded by donations and grants. He says the transfer of sea lice between farmed fish and juvenile salmon is a major concern.
“The salmon farming industry in Clayoquot Sound has shown its inability to control sea lice and continues to threaten wild salmon populations that are experiencing critically low returns,” the report’s executive summary reads.
“The transfer of sea lice to wild salmon can be mitigated by changes to management, notably, the removal of open-net pen salmon farms from migration corridors.”
With the phase-out of existing fish farms already underway in the Discovery Islands, the federal government has targeted 2025 as the year to transition all open-net fish farms from B.C. waters.
Cermaq Canada is aware of the Cedar Coast report and strongly disputes its conclusion.
“We cannot agree with this statement about us not being able to control lice on our farms,” wrote communications manager Amy Jonsson in an email to the Westerly.
“In March 2021, we achieved a seven-year low of average motile sea lice per fish entering the wild juvenile outmigration period, with under one louse per fish on average. We see this as a positive development driven by our investments in innovative and technological solutions, that are demonstrating our ability to control lice levels on our farms.”
In 2018, Bartlett said B.C. fish farms developed a resistance to the SLICE, an infeed sea lice treatment, that resulted in the highest spike of sea lice ever recorded. At one point during the spring out-migration of wild salmon, Bartlett said the industry reported as many as 50 sea lice per fish on a farm site.
Fisheries and Oceans Canada reported the average number of sea lice per fish in 2018 was 13.
“The number of sea lice were definitely better in 2019, but they are still quite high. They weren’t fully able to prevent sea lice outbreaks on farms. Within the terms of licence, they have to keep below three motile lice per fish on farm and they still haven’t been able to keep below that number in either 2019 or 2020,” Bartlett said.”
“Last year, they went over nine separate times. That number was designed to help prevent impacts on wild juvenile salmon during their migration,” said Bartlett, adding that in Norway the motile lice per fish has gone down to 1.5 lice per fish in some areas.
The tenures for Cermaq Canada’s 14 Tofino fish farm sites exist in Ahousaht First Nations territories. Biologist Danny O’Farrell was hired by the Maaqutussi Hahoulthee Stewardship Society (MHSS) to bridge the gap between the industry partners and the six Ahousaht hereditory chiefs (Ha’wiih).
“Ahousaht will no longer work under the DFO guidelines of three motile lice per fish. I’ve addressed (Cermaq) to drop it down to 1.5 moving forward. Now Cermaq must follow a 1.5 versus the industry standard. I think that is a huge breakthrough in the last six months to limit the impact of sea lice on our wild salmon,” O’Farrell affirms.
Cermaq says its sea lice monitoring and reporting has been audited by regulatory bodies since 2005 across all of its marine farm sites.
“As salmon farmers who care about both the health of the ocean and supporting wild salmon populations, we believe that supporting the recovery of wild salmon is critical to the surrounding ecosystem, and we also respect the cultural importance of wild salmon to First Nations,” Jonsson writes. “The decline of wild salmon populations is a complex issue with many factors at play; we are working to make sure we are part of the solution, not part of the problem moving forward.”
The salmon farmer currently uses three tools to combat sea lice in the Clayoquot Sound region: mechanical delousing which loosens and removes the parasites with pressurized sea water, the antibiotic feed treatment called SLICE, and a delousing bath of Interox Paramove 50 (hydrogen peroxide). They are also testing a new semi-closed containment system at the Millar Channel site.
With the wild juvenile salmon migration period taking place from March through to the end of June, Cermaq says it is making every effort to keep sea lice counts as low as possible to help reduce the possibility of lice transferring from farmed to wild populations.
Bartlett says March is usually a time of low sea lice abundance and the real test for how well they can control sea lice is coming. O’Farrell agrees.
“Usually in the spring time and early winter the numbers remain really low because the outbreaks don’t happen until May and June so we’ll just have to wait and see,” said O’Farrell.
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