Hatchery-raised fish show dramatic alterations in their DNA from wild fish in just one generation, says a new study published in Nature Communications by Oregon State University. Researchers compared wild steelhead trout taken from the Hood River with hatchery-raised steelhead, reports The Oregonian. By breeding fish with two wild parents, two hatchery-raised parents and with one of each, researchers found that fish with hatchery-raised parents differed in as many as 700 genes compared to those with wild parents.
The aquaculture industry has long known that hatchery fish don’t survive or reproduce as well in the wild. It’s not yet known what traits the hatchery fish are selecting for or how environmental factors play into the equation. But if hatchery managers can figure those questions out, they could potentially design hatcheries to be more like a fish’s natural environment. Experts say doing so would be good for wild fish, too, since many worry that accidental interbreeding between hatchery and wild fish will ultimately weaken the genetics of wild species.