Chinook salmon run in a British Columbia river.
Photo: Adobe Stock.
Two new peer-reviewed scientific studies concluded that BC salmon farms do not harm wild salmon stocks, thus adding to the view that open net-pen salmon aquaculture poses minimal risk to wild Pacific salmon in British Columbia. "This reinforces a growing body of scientific evidence that supports the coexistence of wild and farm-raised salmon," the BC Salmon Farmers Association (BCSFA) said in a statement releasing those studies.
A study recently published in Aquaculture Research examined whether Tenacibaculosis - commonly referred to as "mouthrot" - in farm-raised Atlantic salmon can be transmitted to Chinook salmon through cohabitation. The study concluded that Chinook salmon cohabitating with infected farm-raised Atlantic salmon showed no illness or mortality, even when exposed to high pathogen concentrations.
The salmon farmers of British Columbia noted that this is the first interspecies transmission study of its kind in Canada, directly addressing public concerns about disease transfer between farm-raised and wild salmon.
The second of the recent studies, this one published in Scientific Data by Nature, provides a comprehensive sea lice dataset compiled for British Columbia's coast, covering over two decades of monitoring across nearly 100 farm sites and more than 365,000 wild fish.
According to the BCSFA, the study's result highlights the variability in sea lice prevalence (percentage of fish with sea lice) across regions and years, and cautions against drawing sweeping conclusions based on limited or localized data, "which has often distorted public perception and influenced policy."
"These studies add to a growing and increasingly rigorous body of scientific evidence concluding that salmon farms in BC do not harm wild salmon populations," Brian Kingzett, Executive Director of the BC Salmon Farmers Association, stated. "Four major peer-reviewed studies have emerged this year alone, reaffirming this conclusion," he added.
The most recent before these last two was a paper published last July in Aquaculture, Fish, and Fisheries that reviewed 20 years of scientific publications, concluding that salmon farms in British Columbia have minimal impact on wild salmon populations, with no solid evidence of long-term impacts.
The fourth, published in April in the Journal of Fish Diseases, was another paper that, in this case, debunked the claim that the elimination of salmon farms results in fewer sea lice in wild Pacific salmon. Thus, after eight years of monitoring in the Discovery Islands - where the phase-out of salmon farms began in 2021, and there have been no active farms since 2022 -, it challenged the key argument of anti-aquaculture activists: no salmon farms, no sea lice.
It will not be limited to four publications. According to the BCSFA release, another paper whose abstract has already been published in Diseases of Aquatic Organisms is forthcoming.
The truth is that as 2029 approaches - the deadline for open net-pen salmon aquaculture in BC after its ban - the number of studies has been multiplying, all of them with similar conclusions, as shown by those reported in WeAreAquaculture in January 2023, August 2024, and December 2024. The salmon farmers of BC are relying on all of them to ask the new Government of Canada to review the ban.
"With the 2029 marine net-pen ban on BC salmon farms approaching, we respectfully urge the federal government to reconsider this decision," said Brian Kingzett. "This policy, initiated under the previous Trudeau administration, is not supported by science and will significantly impact coastal communities and Canadian food security."
The BC Salmon Farmers Association, which represents nearly 60 businesses and organizations throughout the value chain of finfish aquaculture in BC, accounting for over 95% of the annual provincial harvest of farm-raised salmon in British Columbia, noted that the sector generates over CAD 1.17 billion for the BC economy, supporting 4,560 well-paid full-time jobs.
According to it, the current ban on marine open net-pens salmon farms by 2029 risks CAD9 billion in taxpayer costs and significant economic losses not just for British Columbia but to Canada. The Association claimed that, under "a renewed, responsible, Indigenous-led plan," the sector could generate CAD 2.5 billion in annual economic output and 9,000 jobs by 2030, and up to CAD 4.2 billion in annual economic output with over 16,000 jobs by 2040.