By excluding hatchery fish a wild steelhead population will double its productivity, more than double the number of returning adults and double its adult recruits per spawner. It also means that there are more fish available for harvest. With a ten percent improvement in habitat these number increase even more. That is the prediction of a recent scientific evaluation of Asotin Creek in southeastern Washington, a tributary to the lower Snake River above eight mainstem Columbia and Snake river dams.
In 2009 the Hatchery Science Review Group (HSRG) made a recommendation to exclude hatchery steelhead in Asotin Creek to improve the productivity of wild summer steelhead. The Washington Department of Fish and Wildlife (WDFW) has constructed a weir a few miles above the mouth of the creek with the Snake River and has collected data on adult and juvenile steelhead since 2005, and it represents one of the only intensive evaluations of a wild steelhead population in the Columbia River Basin.
Recovery of Columbia Basin salmon runs has long been claimed to be the world’s largest salmon recovery program and has spent over $9 billion to double the runs from 1992 to 2000. That effort, dependent primarily on releasing more hatchery fish, has failed. Artificial propagation promises to mitigate for damaged salmon habitat, but has failed to make up for the losses. The promise was made that hatcheries would increase salmonids available for harvest, but have failed. However, hatcheries have been successful in contributing to the depletion of wild salmonids throughout the basin.
The Asotin Creek evaluation points to a new direction: exclude hatchery fish form the natural spawning population. According to the HSRG analysis the productivity would increase from 1.3 adults recruits per spawner to 2.3; average abundance of wild spawners would increase from 354 fish to 817 fish, and the harvest contribution would increase from 38 fish to 179 fish.
This analysis is confirmed by other studies that show a decline in wild steelhead when hatchery fish are able to spawn naturally with wild fish:
In 2008 Araki et al. evaluated the impact of native brood steelhead hatchery program on Hood River wild steelhead, saying, “We show that genetic effects of domestication reduce subsequent reproductive capabilities by 40% per captive-reared generation when fish are moved to natural environments. These results suggest that even a few generations of domestication may have negative effects on natural reproduction in the wild.”
Michael Blouin of OSU also worked on Hood River steelhead study and said, “If anyone ever had any doubts about the genetic differences between hatchery and wild fish, the data are now pretty clear. The effect is so strong that it carries over into the first wild-born generation. Even if fish are born in the wild and survive to reproduce, those adults that had hatchery parents still produce substantially fewer surviving offspring than those with wild parents. That's pretty remarkable." Blouin added, “"What it means is that if you are trying to help a wild population recover then putting hatchery fish in there is probably not a good idea."
Mark Chilcote (ODFW) published a study in 2003, and concludes, “ Naturally spawning population comprised of equal numbers of hatchery and wild fish would produce 63% fewer recruits per spawner than one comprised entirely of wild fish. For natural populations, removal rather than addition of hatchery fish may be the most effective strategy to improve productivity and resilience.” He added, “a spawning population with 20% hatchery strays (regardless of the type of hatchery program and whether they are integrated or segregated) had the net survival rate (recruits per spawner) that was 20% less than a population comprised entirely of wild fish (0% hatchery strays). Likewise, a population with 40% hatchery strays had a population survival rate that was 40% lower than a population comprised entirely of wild fish.”
Steve Leider in his work on the Kalama River compared the survival of hatchery and wild steelhead and said, “ The mean percentage of offspring from naturally spawning hatchery steelhead decreased at successive life history stages, compared to wild steelhead, from a potential of 85-87% at the egg stage to 42% at the adult stage. Reproductive success of naturally spawning hatchery steelhead compared to wild steelhead decreases from 75-78% at the subyearling stage to 10.8-12.9% at the adult stage.”
Given this and many other sources of information on the impact of hatchery steelhead on wild steelhead the question has to be asked: Why do the recovery programs developed by the states and the NMFS always include hatchery fish as part of the fix for ESA-listed depleted wild salmonid populations?
The simple answer is that hatcheries mean federal dollars for state programs, so hatcheries have to be a central factor in salmonid recovery plans. It also means that because the fish managers are never held accountable to the scientific information they generate, they are free to ignore it and they do.
In a recent paper by Jim Lichatowich and Rick Williams in 2009, they confront this issue head on: “The management agencies must put learning and incorporation of science on the agenda, something which in our experience management agencies have been reluctant to do.”
