This story originally appeared in the Fall/Winter 2025 edition of Salmon Steward, the Pacific Salmon Foundation’s quarterly print magazine.
The Discovery Islands, an archipelago east of Campbell River, form a key migratory channel for Fraser River salmon.
Both adult salmon coming back to spawn and young salmon headed out to the open ocean travel through these waters. Local salmon populations also rear, feed, and grow nearby.
Until recently, open-net pen Atlantic salmon farms operated in the area for decades, raising concerns about the potential spread of pathogens from farmed to wild fish.
Following a decision by the federal government not to renew Atlantic salmon farm licences in the Discovery Islands, open-net pens were phased out of the area between 2021 and 2022.
Understanding how wild salmon respond to the removal of open-net pens over time requires monitoring while the farms are operating and after they are phased out. The Pacific Salmon Foundation (PSF) has stepped in to help lead these vital data collection efforts from 2025 to 2028, building off a legacy of monitoring established by the Hakai Institute, Dr. Kristi Miller-Saunders from Fisheries and Oceans Canada (DFO), and independent scientist Dr. Alexandra Morton.
During the juvenile salmon outmigration season in spring to early summer, PSF’s Salmon Health Program, along with partners from the University of Toronto and the local area, sampled juvenile salmon for pathogens, counted sea lice, and studied other environmental factors as the fish migrated past now-inactive salmon farms.
“This research matters because we’re seeing salmon declines across their range. They’re facing many stressors, with impacts from Atlantic salmon farms among them. By monitoring wild salmon after the farms are removed, we’ll be able to see if salmon are recovering,” says Dr. William Bugg, a postdoctoral scientist with PSF.
“Without this fieldwork, we risk losing a critical opportunity to monitor juvenile wild salmon during this key period of change.”
Farmed and wild salmon in close quarters
To monitor for pathogens and environmental stressors, PSF’s field crew samples juvenile salmon and applies ‘Fit Chip’ technology — similar to what’s used in personalized human medicine — to screen salmon for overall health. The team simultaneously collects environmental DNA from surrounding waters for the presence of pathogens and viruses. Together, these measures will reveal how juvenile salmon are doing now that the farms have been removed.
In collaboration with numerous partners, PSF has published a mountain of peer-reviewed, independent research clearly linking open-net pen salmon farms to risk factors for wild Pacific salmon in B.C.
Open-net pen salmon farms, set to be phased out of B.C. entirely by 2029, raise Atlantic salmon in crowded pens in the ocean. Such conditions make farmed fish a breeding ground for pathogens that can spread to wild salmon migrating nearby.
In the Discovery Islands, open-net pens have been absent for several years. The field crew may be starting to see the effects.
“We are seeing huge numbers of healthy-looking local salmon,” says Kyra Ford, fisheries health technician with PSF, adding that the fish “have persisted much later into the summer than when the farms were around.”
This work is co-led by the University of Toronto, with critical support from Raincoast Research Society and funding from the Natural Sciences and Engineering Research Council of Canada.
