BY ROCKY BARKER
For years biologists have clashed over the role that hatcheries should play in restoring salmon.
Tribal biologists have followed the lead of Indian fisherman pushing supplementation of wild stocks of salmon with hatchery stocks. Previous research and genetic experiments have suggested releasing hatchery stock into the wild weakens the genetics of the wild stocks and reduces the overall productivity of the surviving fish.
So you had the tribal view that “a fish is a fish,” versus the view that the genetic purity of the native fish evolved in its watershed made it superior. Over the last 20 years the two sides have come together a bit, still, the divide remains.
But a new study published this week in the journal Molecular Ecology shows that Nez Perce Tribe’s Johnson Creek Artificial Propagation Enhancement got the same reproductive success from hatchery-reared salmon that spawned with wild salmon as salmon left to spawn in the wild.
“The Johnson Creek research clearly demonstrates how supplementation programs can boost populations and minimize impacts to wild fish populations,” said Dave Johnson, Nez Perce Tribe Fisheries Program Manager.
The study used DNA from all returning adults collected over a 13-year period to track parents and their offspring, much as Idaho Fish and Game does in its sockeye program. It also showed biologists how successful hatchery fish were at mating in the wild when compared to wild fish.
