Salmon Numbers Remain Lowby Greg Moore
Idaho Mountain Express, September 5, 2007
Four sockeye swim to Redfish from Pacific
Efforts toward recovery of salmon on their namesake river continue an uphill battle, with 1,549 returning Chinook salmon having been counted at the Sawtooth Hatchery near Stanley by Sept. 4. This Friday, Sept. 6, will be the last day of counting.
As of Aug. 28, only four sockeye salmon had been counted returning from the Pacific Ocean to their namesake Redfish Lake, where they once spawned by the thousands. The sockeye program is primarily a gene-banking program, rather than a recovery program, and far fewer sockeye smolts are released than are Chinook smolts.
The number of returning sockeye in recent years has varied tremendously, from a low of three in 2003 and 2006 to 257 in 2000. Most years, the number is in the 20s.
"These are some of the poorest returns we've seen in recent years," said Mike Peterson, a fisheries biologist with the Idaho Department of Fish and Game. Peterson said sockeye return numbers have been low throughout the Columbia River basin, which includes the upper Columbia and Fraser rivers in British Columbia.
He said biologists suspect that unusually high temperatures in the upper Salmon River, caused by a low snowpack and hot summer weather, contributed to the low survival rate here. He said water temperatures reached 75 degrees, near the survival limit for salmon.
Roger Elmore, assistant manager of the Sawtooth Hatchery near Stanley, said the 1,549 returning Chinook there are about a normal number, though last year only 761 fish returned. He said one anomaly this year is that a large percentage of the returning fish (1,259 of them) are "jacks," fish that have spent only one year, as opposed to two, in the ocean.
"It's a hopeful sign," he said.
Lots of jacks mean good recent conditions for salmon survival in the ocean. That means a likelihood of a good return next year for 4-year-old fish, which will have spent two years in the ocean.
However, it also means that hatchery employees have fewer than the normal number of adult females from which to draw eggs. Elmore said the hatchery will probably spawn about 70 females this year, far fewer than the 325 the facility can handle.
Biologists have placed most of the blame on the dramatic declines in migrating salmon on the four dams built on the lower Columbia River and the four dams built on the lower Snake River. However, they acknowledge that they have little information on how the fish are affected by other factors.
Peterson said that in 2005, the year the currently returning fish were released, about 68,000 sockeye smolts made it downstream to Lower Granite Dam, the first of the eight dams they encounter heading downstream. From there, they are barged around all eight dams.
"We really don't know where the majority of the mortality occurs," he said.
He said survival conditions for salmon in the ocean depend on varying temperatures and current patterns, and that much remains to be studied. Peter Hassemer, anadromous fish manager with the Idaho Department of Fish and Game, said the state's sockeye program is primarily a holding operation until the environmental factors affecting the fish can be changed.
"We're trying to make sure we have this species so that when the opportunity presents itself, we'll have the closest thing to a native population to work with," he said.
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