Oregon research shows that steelhead raised in captivity are hurting wild-born fish. Ethan Lindsey reports.
Scientists have long found hatchery-raised fish have a much tougher time in the wild.
The thinking goes that the fish have adapted to an unnatural habitat and are less fit for the real world.
Now an Oregon State University zoology professor found the captive-born fish inter-breed and pass on their weaknesses to wild fish.
Michael Blouin, and two other researchers, published the study in the journal Biology Letters.
Michael Blouin: “You have hatchery fish breeding in the same river with wild fish. If the hatchery fish are genetically worse, they are dragging down the fitness of the wild fish. So, adding hatchery fish to a wild population is very likely to harm the wild population, in a genetic sense.”
The research focuses on steelhead – but Blouin says the data could be used to draw similar conclusions about salmon and other fish.
Regional fish agencies say they may change the way they use hatchery fish as a result of this research.