Captive-bred steelhead trout used to boost declining fish populations are less fit than wild-bred trout, raising concerns over conservation programs for endangered species, says a new study
Research published in Friday's edition of the journal Science shows that hatchery-raised steelhead trout dramatically and unexpectedly lose their ability to reproduce in the wild.
Oregon State University researchers found the reproductive success of trout, a species critical to many healthy aquatic ecosystems, drops by close to 40 per cent for every generation they spend in a hatchery.
"For fish to so quickly lose their ability to reproduce is stunning, it's just remarkable," Oregon State University zoologist Michael Blouin said in a release.
"We were not surprised at the type of effect but at the speed. We thought it would be more gradual. If it weren't our own data I would have difficulty believing the results."
The finding raises concerns over restocking programs around the world that rely on hatchery-raised fish to re-establish healthy numbers of top-predator fish and keep the aquatic food chain in balance.
