Drought devastates salmon fry countgreenspun.com : LUSENET : Grassroots Information Coordination Center (GICC) : One Thread
>Drought devastates salmon fry count
Dams also to blame as millions of fish die in Columbia River
Wednesday, August 22, 2001
By LISA STIFFLER
SEATTLE POST-INTELLIGENCER REPORTER
Trapped in evaporating puddles and among drying cobblestones, more than 1.6 million baby wild salmon died in the middle Columbia River this spring as they tried to migrate downstream.
And that's only on the 17-mile stretch surveyed by the state. The number of dead fall chinook could be more than 3 million throughout the entire 51-mile run of the fish, the state Department of Fish and Wildlife estimated yesterday.
The department blamed a combination of drought and dam operations for the unusual devastation. And it warned that fishing restrictions are possible as a result.
At issue is the healthiest run of wild fall chinook in the state. The fish, which are not listed as threatened or endangered, are an important source of salmon for sport, tribal and commercial fisheries.
"They mean so much to salmon advocates," said Charles Hudson, spokesman for the Columbia River Inter-Tribal Fish Commission. "The Hanford Reach fall chinook are the backbone of the tribal fishery."
When they hatch, the salmon are weak swimmers and move to the edges of the river, where currents are slower. Along the riverbanks, the fry find food and shallow water that protects them from larger, hungry fish. But the shallows can also leave them trapped when water levels fluctuate because of drought and flow regulation by dams.
The state surveyed the 17-mile stretch of river below the Priest Rapids Dam, where the fish spawn each year between April and June. The dam is operated by the Grant County Public Utility District.
This year, water fluctuations caused by dam operations were less than in previous years, but low water due to the drought exacerbated their impact, said Rod Woodin, Columbia River policy coordinator for Fish and Wildlife.
As the river ebbed and flowed, shrinking pools trapped the fish and suffocated or cooked them as Eastern Washington temperatures soared. They also were easy picking for airborne predators.
"This is the biggest fish kill that I'm aware of this year," said Craig Bartlett, spokesman for the Department of Fish and Wildlife.
It's also the largest loss of fry tabulated in the fall chinook run since monitoring began three years ago. The number of dead baby fish along the surveyed stretch of river increased more than 2000 percent since last year, when 72,000 fry were killed. Nearly 126,000 fry perished in 1999.
Luckily more fry hatched this year than in recent seasons. Approximately 23.8 million fall chinook were born in 2001, up from an estimated 17.9 million fry in 2000. The average number of fry since 1998 has been approximately 20.9 million.
Hudson said this run is the last successful naturally spawning population and deserves protection.
"We don't see the sense in taking a healthy run and making it a listed run," he said.
Grant PUD has worked with state and federal agencies as well as tribal representatives to determine how water flow should be regulated during spawning and hatching.
Joe Lukas, fisheries scientist with the PUD, said during the winter its dams were forced to release more water to help downstream chum salmon, so when spring came along, their options were few.
"We felt like we got dealt a really tough hand," Lukas said. "We didn't have the water to work with. We're going to work hard to learn how to manage flows in a drought year."
Earlier this month an Eastern Washington Indian nation and a giant utility company announced they would try to win control of the Priest Rapids Dam and neighboring Wanapum Dam, which generate power for the region. Grant PUD's license for the dams runs out in 2005. Flow levels can be addressed in the licensing process.
Because of the huge loss of fry, fluctuations in flow will need to be more stringently regulated, and the agency will carefully monitor the number of juveniles that hatched this year that return to the river in coming years, Woodin said. The number of wild fall Chinook caught by fishermen may need to be curtailed.
"Obviously we didn't do nearly as good a job as we had hoped to this year," Woodin said. "We'll take this information and try to learn from it and try to do better."
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