The small population of sockeye salmon struggling to survive in the Columbia River has declined even further this season, raising worries about sustaining the wild run.
So far, more than 37,000 sockeye - out of a projected run of 40,000 - have passed Bonneville Dam. The run still is far below the 75,000 viewed as a relatively healthy return.
Sockeye, or red salmon, normally are associated with Canada’s Fraser River or Alaska’s Bristol Bay. Yet the Columbia has a small run that peaks in early July.
At the Columbia Inter-Tribal Fish Commission engineering and research lab, researchers divert fish swimming up the fish ladder on the Washington side of Bonneville Dam.
Chinook, steelhead and sockeye salmon are routed through a small building, where they are captured, measured and checked for signs of gas bubble disease, a potentially fatal disorder triggered by heavy water spills at the dams.
“We see more symptoms of gas bubble disease in sockeye than any other fish,” says Glen Szerlong, a technician with the commission.
Szerlong says 65 percent of the sockeye have had symptoms of the disease, which is similar to a diver getting the bends. He says sockeye may swim higher in the water, making them more vulnerable.
This spring’s record runoff prompted Columbia River dams to spill enormous volumes of water. Higher flows help salmon and steelhead smolts migrate to sea, but foaming rapids below dams pump high levels of nitrogen into the water.
Most of the sockeye are bound for two lakes in Washington state and British Columbia. A handful may be headed to the Snake River, where sockeye have been protected as an endangered species since 1991.
“These are resilient fish,” says Paul Hirose, a biologist with the Oregon Department of Fish and Wildlife.
Historically, the Columbia had millions of sockeye in eight sub-basins, including Wallowa Lake in northeast Oregon and Suttle Lake in the Metolius River drainage of central Oregon.
Today, the lake-loving salmon survive in just three areas: Lake Wenatchee in Eastern Washington; Osoyoos Lake in the Okanogan River drainage on the Washington-British Columbia border and Redfish Lake in Idaho.
The Redfish Lake sockeye are listed as endangered under the Endangered Species Act. So far this year, just one sockeye has passed Lower Granite Dam, the first dam on the Snake. Only 3 three sockeye returned to the Snake River last year, and only 48 fish since 1989.
Lake Wenatchee, a cold, relatively sterile lake, was never a big source of sockeye, but it produces the most stable part of the Columbia run. The fish spawn in lake tributaries, the White, Napeequa and Little Wenatchee rivers.
Nez Perce Indians once dried sockeye on the shores of Wallowa Lake in northeast Oregon. In the 1890s, about 30,000 sockeye returned each year, and two canneries operated on the lake shore.
But in the 1900s, the Oregon Department of Fisheries launched a disastrous program to breed Wallowa sockeye. The department seined adults downstream and effectively doomed the run. A dam rubbed out what was left in 1929. A federal effort to restore sockeye to the Yakima basin has been unproductive, and the last fishery for Lake Wenatchee sockeye was in 1992.
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