State Uses Hatchery Carcasses
by Jonathan Brinckman
Biologists say the program is a temporary measure
to help restore the natural populations of fish
State fish and wildlife officials plan to dump salmon and steelhead carcasses into more than 300 streams in Oregon this year, sharply expanding a program designed to restore nutrients to waterways where wild salmon spawn.
The bodies of hatchery fish that have been killed for their eggs and sperm are tucked into logjams or snagged on rocks so they won't wash away. Young salmon feed directly on the carcasses and on the insects that also feed on the spawned-out salmon bodies.
Last year, the state program put 8,511 dead salmon and steelhead into 68 streams in Western Oregon. State and federal workers and volunteers carried frozen salmon carcasses in gunny sacks to streams and rivers.
This year, managers have targeted more than 332 streams for the program, which started in September and will continue through April.
The total number of dead salmon to be put in the streams will depend on how many fish return to hatcheries in the coming months. With hatchery returns running high so far this year, the Oregon Department of Fish and Game expects to have plenty of fish available. The program is in its fourth year.
A recent study by the Washington Department of Fish and Wildlife found that salmon carcasses feed young salmon and at least 137 other species of fish and wildlife. One National Marine Fisheries Service researcher reported that 40 percent to 60 percent of the stomach contents of young salmon and steelhead could be traced to the bodies of decaying salmon carcasses or insects that feed on those bodies.
As Northwest salmon runs have declined in recent decades, so has the food supply for young salmon. State biologists say that introducing hatchery bodies is a temporary measure to help restore wild populations.
Fishing clubs, high schools help Barry McPherson, fish restoration program manager for the state Fish and Wildlife Department, said he's excited by the program and pleased with all the help from volunteers who include members of fishing clubs and high school students.
But hatchery carcasses can never replace wild salmon, McPherson said. For one thing, wild salmon also improve streams by digging up and moving gravel when they build their redds, or nests. That aerates the gravel and helps feed young salmon and other fish by knocking aquatic insects loose.
Dead salmon are full of nutrients that at high levels can overwhelm streams and cause oxygen levels to plummet. The Oregon Department of Environmental Quality considers the bodies a pollutant. Nonetheless, the agency supports the salmon carcass program and has issued the needed permits.
"We agree that, if distributed properly, the carcasses provide nutrients that help juvenile salmonids," said Bob Baumgartner, water quality manager for the agency's Northwest Region. "The literature shows this translates into larger, healthier juveniles."
Dick Caldwell, a biologist in the Fish and Wildlife Department's Clackamas office, coordinates the placement of carcasses in three Portland-area streams: Still Creek, a tributary of the Salmon River in the Sandy River watershed; the North Fork Eagle Creek in the Clackamas River watershed; and Bear Creek, a tributary of North Fork Eagle Creek.
Caldwell praises volunteers from David Douglas High School and Central Catholic High School and from the Sandy River chapter of the Northwest Steelheaders Association. "They're going out there in adverse weather, toting around these dead frozen fish," he said. "It's pretty darned good."
Washington and British Columbia have experimented with boosting the productivity of streams using fertilizer or pellets made of fish meal. But Oregon is skeptical about such programs and wants to use methods that are as natural as possible, McPherson said.
He rejected a proposal to anchor the dead salmon in place with wooden stakes to keep them from washing downstream. "We'd get phone calls from people saying there's a cult out there driving stakes though the hearts of salmon," he said.
Headwater Nutrient Loss Idaho's Fish: Status & Recovery, Idaho Fish & Game
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