Sockeye Sighted on Their Way Back to IdahoBy N.S. Nokkentved, Times-News - July 25, 1999
TWIN FALLS -- Sockeye salmon, which turn bright red when they are ready to spawn, gave their name to Redfish Lake. They have been returning from the Pacific Ocean for untold thousands of years, and this year they are on their way as usual.
Biologists reported last week that seven sockeye had been sighted above Lower Granite Dam on the Snake River on their way to Redfish Lake. But the seven fish still have 430 miles to go.
But that's still more fish than biologists expected, said Paul Kline, principal fishery research biologist at the Idaho Department of Fish and Game's hatchery in Eagle. Seven fish so far this year are the most since 1993, when 12 were counted at Lower Granite, he said.
Last year three sockeye were sighted at Lower Granite. Only one returned to the lake.
They once returned in runs of tens of thousands to spawn in the shallow waters along the shores of the lakes of the Sawtooth Valley. The runs were blocked in 1910, but somehow the fish survived.
Eleven miles east of Lower Stanley, below the shoulder of state Highway 75, the remains of the Sunbeam Dam, the only dam ever built on the Salmon River, still are visible.
The dam was built in 1910 about 20 miles downstream from the mouth of Redfish Lake Creek. A wooden fish ladder was added in 1912, but it washed out during the first high water. It was replaced by a concrete fish ladder in 1920.
Without effective fish ladders, the dam all but blocked the passage of the returning sockeye. But early eyewitness accounts tell of sockeye upstream of the dam and in Redfish Lake in the 1920s and 1930s.
In 1934, sport fishermen took the matter into their own hands and breached the dam with a charge of dynamite. Fish and Game officials enlarged the opening.
The fish began to recover, Kline said. The most likely explanation is that some sockeye spend their entire lives in the lake. The offspring of this "residual" population may head for the ocean.
The surviving sockeye population in Redfish Lake most likely are the offspring of these residual sockeye. The sockeye share the lake with resident kokanee salmon.
In 1942, 200 adult sockeye were counted in the lake. In 1954, the number was about 1,000. The following year, more than 4,000 adult sockeye were counted returning to the lake. Biologists thought the run was starting to rebuild from the effects of the Sunbeam Dam, Kline said.
The returning fish show that salmon have the ability to rebound when conditions in the ocean or the river turn in their favor, he said.
But in recent decades the fish numbers have gone into a new downward slide.
It is not clear what led to the bad years, but probably it was a combination of factors, Kline said.
In 1991, the National Marine Fisheries Service listed the Snake River sockeye as endangered under the Endangered Species Act.
Chinook were listed as threatened in May 1992, and Snake River Basin steelhead were added on Aug. 18, 1997.
The residual sockeye in Redfish Lake may be the hope for perpetuation of the species, but the numbers are shrinking, Kline said.
Last year, the lone male that returned to Redfish Lake was trapped before it entered the lake for use in the captive brood program at the Eagle Hatchery. The sockeye normally spawn in September or October, and they once returned to Redfish, Alturas, Stanley, Pettit and Yellow Belly lakes in the Sawtooth Valley.
The fish on their way to Redfish Lake this year most likely left Idaho in 1997, when an estimated 300 naturally produced smolts and roughly 400 six-month-old hatchery fish were released. The sockeye normally spend two years in the ocean before returning to spawn.
But all the returning fish are small, and some think they may returned after spending only one winter in the Pacific Ocean. That's unusual for sockeye, Kline said.
From 700 smolts, Kline would expect less than one fish to return. Return rates in recent years have been just under one adult per 1,000 smolts.
In 1998 about 1,000 wild sockeye and 13,000 hatchery fish emerged from Redfish. That was the first year that the brood stock program adults and eggs were planted in the lake, boosting the hatchery smolt component.
The wild smolts are produced by a combination of ocean-going sockeye and lake resident sockeye. Both spawn at the same time.
Studies done with the help of the Shoshone-Bannock tribes on nutrients in the lake bottoms of Redfish, Alturas and Pettit lakes show that in ancient times, sockeye came back in tens of thousands.
Mountain lakes typically are quite sterile, but the sockeye made a difference. After spawning in shallow lakeshore gravel, they died, leaving their decomposing carcasses to fertilize the lakes.
The decomposing fish feed plankton on which young salmon and other wild fish feed in turn. Since sockeye no longer return to these lakes, the lakes may not be getting enough fertilizer to support young, growing salmon.
Once hatched the young sockeye stayed in the lakes for one or two years. The amount of plankton available determined how big and strong they were. The bigger they are, however, the better they would survive their lengthy sojourn to the ocean, where they mature and then return to their native lake to spawn and die.
One of the programs the Shoshone-Bannocks are working on with the state is studying the effects of adding fertilizer to the lake. The Indians also are working on several other projects to get the sockeye back in the streams, said Chad Colter, a fisheries biologist with the tribes.
The fish -- as all fish and wildlife -- are important to the tribes as a natural resource that once helped feed some bands of the tribes' nomadic ancestors.
But the runs are dwindling, Colter said. The species is sensitive and among the first to feel the effects of barriers in the migration route.
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