Can Hatcheries Help Recover Coho Salmon?

Eugene - A study by independent scientists indicates that Oregon coastal coho salmon populations are unlikely ever to be restored by fish hatcheries. The study underscores that recovery of dwindling salmon runs depends on the protection and restoration of freshwater habitat.

The study's purpose was to answer the question, Under what circumstances could hatchery fish stocking contribute to the recovery or viability of natural populations of Oregon Coast Coho salmon? Independent researchers Gretchen Oosterhout and Charles Huntington adapted an existing life-cycle model for coho salmon to enable computer simulation of interactions between wild and hatchery fish in a river basin. The new model examined the potential effects of proposed state-of-the-art conservation hatchery designs intended to reduce negative effects on wild fish while boosting failing returns of salmon. Nicknamed CoRAS, the model is believed to be the first to simulate the population dynamics between Oregon coastal hatchery and wild coho salmon.

"The main finding is simple, but important," said Dr. Chris Frissell, Pacific Rivers Council Senior Scientist and part of the study review team. "Even the best hatcheries we can design pose a clear risk of harm, but promise little or no benefit to populations of salmon breeding in the wild."

In addition to hatchery-wild interactions, the model also simulated the effects of other management interventions and climatic fluctuations on wild populations. "The results indicate that of all the things humans can do, freshwater habitat restoration offers the only significant and permanent gains in salmon abundance," explained Frissell. "The bottom line is that it's habitat restoration and wild fish populations that will determine salmon recovery. Counting fish that originated from hatcheries is a delusion -- it merely places a temporary mask over what is really happening to wild salmon populations and the rivers they depend on to survive."

The Pacific Rivers Council finds there are at least three important public policy implications:

• Status determinations, recovery plans, and recovery goals for salmon should not assume that hatchery-origin salmon are an integral component of the wild population.
• New, often very expensive "conservation hatchery "or "supplementation" programs, at best, likely will be only marginally more effective than past practices in providing any benefit to natural fish populations.
• Protection and restoration of freshwater habitat are the critical steps necessary for the recovery of natural salmon populations.

"Rumors are flying about high-level political deals to remove Endangered Species Act protection for coastal coho," notes PRC Executive Director David Bayles, "This study confirms that it would be a grave mistake, and probably illegal, to remove endangered species protections for wild coho because of more and supposedly better hatchery fish going into our rivers."

To read a summary of the report, click here.

To download the full report or order a hard copy, click here.

To learn more about PRC's work defending the intent of the Endangered Species Act, click here.