New peer-reviewed findings show the evidence does not support the narrative that “no salmon farms mean no sea lice”, raising fresh questions about Ottawa’s activist-induced plan to curtail ocean-based aquaculture in British Columbia.
By Fabian Dawson
SeaWestNews
The foundational myth behind BC’s anti-salmon farming movement, that no ocean farms means no sea lice, is unraveling in the face of overwhelming scientific proof.
A new peer-reviewed study, published this week in Diseases of Aquatic Organisms, shows that even after the removal of salmon farms in the Broughton Archipelago, sea lice levels on wild juvenile salmon have remained unchanged or even increased in the region.
The findings strike at the heart of the “no farms means no sea lice” claim that has been used by activist groups to influence federal government policy and public opinion for over a decade.
The research analyzed nine years of data, examining nearly 3,000 juvenile pink and chum salmon between 2016 and 2024. During this period, aquaculture production in the Broughton dropped by more than 95%, from 21,645 tonnes in 2019 to just 614 tonnes in 2024.
Yet, sea lice prevalence spiked in 2022 while production was already in steep decline and rose again in 2024, after most of the Broughton farms had been removed.
“This study provides clear scientific evidence that the removal of salmon farms does not invariably lead to reduced sea lice infestation levels on wild Pacific salmon,” said Dr. Crawford Revie, Professor of Data Analytics at the University of Strathclyde in the UK.
“These findings highlight the importance of understanding the range of natural environmental processes that shape sea lice population dynamics,” he said.
The data revealed no correlation between salmon farm biomass and sea lice levels. In fact, some of the lowest parasite levels were recorded in years with higher farm production in the Broughton, such as 2017 and 2019.
This latest Broughton study mirrors earlier peer-reviewed research published in April, which examined eight years of sea lice monitoring in the Discovery Islands by the same team.
That study, co-led by Fisheries and Oceans Canada scientist Dr. Simon Jones and Mainstream Biological Consulting director Lance Stewardson, found that sea lice levels in 2024 were among the highest ever recorded, despite there being no active farms in the region since 2022.
“These findings demonstrate that the evidence does not support the narrative of ‘no salmon farms mean no sea lice,’” said Stewardson.
“Our findings disprove the claim that salmon farms are the sole driver of sea lice on wild Pacific salmon in the near-shore environment and underscore the need for continued monitoring,” he said.
Sea lice are naturally occurring parasites found on many species of marine fish. They pose no risk to humans. Studies have consistently shown that in BC, regardless of the presence or absence of salmon farms, there is wide variability in sea lice prevalence in coastal locations.
Farm-raised salmon are free of sea lice when they enter the ocean, but during the migration season adult wild salmon may pass sea lice to farm-raised salmon.
Together, the two new studies strengthen the conclusions of a 2022 Canadian Science Advisory Secretariat (CSAS) review, and an updated paper published last June, which found no statistical correlation between farmed salmon and sea lice on wild stocks.
The timing of these results is politically significant. Ottawa is moving forward with a 2029 phase-out of all open-net pen salmon farms, a policy announced in June 2024 by the previous federal government, largely under pressure from anti-salmon farming activists.
The ban threatens 4,560 jobs across BC, including about 1,000 held by Indigenous workers, and could expose taxpayers to $9 billion in compensation claims from salmon farmers, suppliers, and affected First Nations.
The BC Salmon Farmers Association (BCSFA) argues that the Trudeau-era decisions were made on ideology rather than evidence. With livelihoods, food security, and the economy of coastal communities at stake, industry leaders, Indigenous partners, and business groups are pressing Prime Minister Mark Carney to change course.
“Now more than ever, Canada needs homegrown, responsibly raised and affordable protein,” said Brian Kingzett, Executive Director of the BC Salmon Farmers Association.
“With the federal government’s new focus on advancing the competitiveness of Canada’s fish and seafood sector and ongoing research supporting farm-raised and wild Pacific salmon co-existence, now is the time to reconsider the policy decisions harming rural communities and undermining food sovereignty,” he said.
Salmon farming contributes $1.17 billion annually to BC’s economy and has become a cornerstone of Indigenous economic development. All operating farms in the province are under agreements or partnerships with local First Nations.
Earlier this week, the Ahousaht First Nation and its aquaculture partner Cermaq Canada announced a major breakthrough in sea lice management, achieving a dramatic reduction in lice levels over the past year without a single mechanical treatment at 12 active salmon farms on the west coast of Vancouver Island.
This success, combined with the new scientific findings, paints a complex picture of sea lice ecology, one in which farms are not the primary culprit and where Indigenous-led partnerships are actively improving environmental outcomes, said Kingzett.
Beyond the science, this issue has broad implications for Canada’s food security, economy, and rural coastal communities, he said.
“Salmon farming in BC generates thousands of jobs, provides a low-carbon source of protein, and supports rights and title through agreements and partnerships with First Nations whose territories the farms operate in.”
Main image, courtesy of BCSFA, shows a salmon farm in British Columbia