Salmon hatcheries, which are meant to boost wild fish numbers, often harm native populations, according to an analysis.
Hatcheries breed and raise fish in a controlled, captive setting. They can be a tool for wildlife conservation when they are used to recover wild populations and support sustainable recreational fisheries, according to the U.S. Fish and Wildlife Service.
However an analysis titled A global synthesis of peer-reviewed research on the effects of hatchery salmonids on wild salmonids, which examined more than 200 studies, showed the negative impacts, such as poor health and reproductive outcomes, of hatchery fish on wild salmon populations.
"Our review suggests hatcheries commonly have adverse impacts on wild salmonids in freshwater and marine environments. Future research on less studied effects...could improve knowledge and management of the full extent of hatchery impacts," the analysis stated.
The global studies, which took place between 1971 and 2021, were analyzed by scientists at the nonprofits Trout Unlimited based in Virginia, and The Conservation Angler out of Washington, along with the University of Washington, the University of Montana and the Université Laval, in Quebec, Canada.
The analysis was published in July in the journal Fisheries Management and Ecology.
Newsweek has reached out to Trout Unlimited and Conservation Angler via email for comment.
According to the analysis, of the 206 studies 83 percent revealed hatchery programs had adverse effects on wild salmonids, with just 3 percent of hatcheries globally found to benefit wild populations.
John McMillan, science director at The Conservation Angler who worked on the analysis, told the Alaska Beacon that despite research showing most hatchery programs hurt wild fish populations, it's often controversial to criticize them.
"It's frustrating from a scientific point of view, because you can see what the science suggests, but it's understandable why we've been reluctant to move our position on hatcheries, because of the social implications," McMillan said.
"This is one of those things, like climate change, where we have to sit back and think about our relationship with the animal, what it means to us and how much we want to give up so these animals can truly, potentially rebuild themselves," he added.
Earlier this month concerns surrounding wild salmon in farms, where fish are raised for food, were raised when the International Union for Conservation of Nature (IUCN) released its first red-list assessment for the freshwater fish category, finding that roughly 20 percent, or one-fifth, of all such species now face the threat of extinction.
According to the IUCN's report, the Atlantic salmon, a species known to live in freshwater and saltwater habitats, once classified as "least concern," has now been moved to "threatened."
As noted in a report from The Guardian, these wild salmon populations in the Atlantic are facing a unique concern due to the trend of farmed salmon escaping captivity and intermingling with them, as the outlet noted that breeding between wild and farmed salmon produces offspring that are less able to adapt to the effects of climate change.
Correction 3/27/24 1:50 p.m. ET: The headline and story were amended to illustrate the distinction between hatcheries and fish farms.
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
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Natalie Venegas is a Weekend Reporter at Newsweek based in New York. Her focus is reporting on education, social justice ... Read more
