A new collection of more than 20 studies by leading university scientists and government fisheries researchers in Alaska, British Columbia, Washington, Oregon, California, Russia and Japan provides evidence that salmon raised in man-made hatcheries can harm wild salmon through competition for food and habitat.
Published in the May issue of “Environmental Biology of Fishes,” the research brings together 23 new peer-reviewed studies carried out across the entire range of Pacific salmon, including some of the first studies describing the impact of hatcheries on wild salmon populations in Japan and Russia.
The studies provide new evidence that fast-growing hatchery fish compete with wild fish for food and habitat in the ocean as well as in the rivers where they return to spawn. The research also raises questions about whether the ocean can supply enough food to support future increases in hatchery fish while still sustaining the productivity of wild salmon.
“This isn’t just an isolated issue,” said Pete Rand, a biologist at the Wild Salmon Center and a guest editor of the publication. “What we’re seeing here in example after example is growing scientific evidence that hatchery fish can actually edge out wild populations. The scale and magnitude of our current hatchery production system is enormous. Five billion juvenile salmon are released each year worldwide, and the prospect of additional increases in hatchery production is worrisome for the long-term survival of wild salmon.”
