Two new peer-reviewed studies examining disease transfer and sea lice in British Columbia found no evidence of negative impacts from salmon farms on wild Pacific salmon.
Recently published in Aquaculture Research, a study titled “Tenacibaculosis Caused by Tenacibaculum maritimum Is Not Transmitted From Atlantic Salmon (Salmo salar L.) to Canadian Chinook Salmon (Oncorhynchus tshaqytscha W.) in a Cohabitation Model” 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. This marks the first interspecific transmission study of its kind in Canada, directly addressing public concerns about disease transfer between farm-raised and wild salmon.
An additional paper, recently published in Scientific Data by Nature titled “Sea lice infestation dataset for wild and farmed salmon populations on the Pacific coast of Canada (2001-2023)”, provides the most 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. The study 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,” said Brian Kingzett, executive director of the BC Salmon Farmers Association. “Four major peer-reviewed studies have emerged this year alone, reaffirming this conclusion.”
In April, a paper published in the Journal of Fish Diseases dismissed the claim that removing salmon farms results in lower sea lice numbers on wild Pacific salmon.
In July, another paper in Aquaculture, Fish, and Fisheries reviewed 20 years of scientific publications to conclude that salmon farms in British Columbia pose minimal impact on wild salmon populations, with no solid evidence of long-term impacts.
An additional publication is also forthcoming. The abstract, published in Diseases of Aquatic Organisms, previews the upcoming paper “Trends in sea lice infestations on chum salmon (Oncorhynchus keta) and pink salmon (O. gorbuscha) in the Broughton Archipelago, British Columbia remain unchanged despite removal of finfish aquaculture.”
As part of the sector’s ongoing commitment to transparency, in April 2024, the BC Salmon Farmers, in partnership with the Coalition of First Nations for Finfish Stewardship and the BC Centre for Aquatic Health Sciences, released a comprehensive 500-page science review titled “Modern Salmon Farming in British Columbia.” The report includes contributions and data from First Nations, Pacific Ocean scientists, the sector, subject matter experts, government and eNGOs.
“With the 2029 marine net-pen ban on BC salmon farms approaching, we respectfully urge the federal government to reconsider this decision,” said 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 current ban on marine net-pens by 2029 risks $9 billion in taxpayer costs and significant economic losses to Canada. Under a renewed, responsible, Indigenous-led plan, the sector could generate $2.5 billion in annual economic output and 9,000 jobs by 2030, and $4.2 billion in annual economic output with over 16,000 jobs by 2040.
