[env-trinity] Salmon count down;
Low tally reels in the attention of scientists
tstokely at trinityalps.net
Thu Jan 26 16:09:38 PST 2006
Salmon count down; Low tally reels in the attention of scientists
Redding Record-Searchlight - 1/26/06
By Dylan Darling, staff writer
Fall salmon spawning numbers on the Salmon River, about three hours northwest of Redding, could set a new low for the second consecutive year, according to calculations by the California Department of Fish and Game.
The numbers won't be final until March, but early estimates are that only 320 fall-run chinook made it to the spawning beds of the Salmon, a tributary of the Klamath River, last fall.
In comparison, 6,000 salmon returned to the Salmon River in 1997 - the highest number recorded since 1978, the first year records were kept. The fall 2004 run on the tributary, which originates in the Trinity Alps and empties into the Klamath north of Orleans in Humboldt County, saw only 333 salmon.
What's causing the low numbers?
"We're not exactly sure," said Sara Borok, a fisheries biologist with Fish and Game who heads up the Salmon River count.
Possibilities include adult and juvenile fish kills in recent years, warm river water and poor ocean conditions. In addition, inclement weather that rained out some salmon surveys could have contributed to the low tally.
Although fall 2005 numbers for waterways that feed the Klamath other than the Salmon were higher than they were in 2004, they look to be low enough that there will be a limited sport and commercial harvest in the Klamath watershed this year, Borok said.
The Klamath River has averaged 107,000 fall-run chinook in the more than 20 years records have been kept.
The numbers are higher in the upper Sacramento River basin. According to Doug Killam, a fisheries biologist in Red Bluff, about 272,000 chinook came back to spawn in the fall, about 100,000 more than the average from 1996 and 2004.
Twice weekly, from October into December, scientists from Fish and Game, the U.S. Fish and Wildlife Service and members of tribes living in the vicinity wade through the chilly waters of the Salmon River looking for salmon carcasses. Last fall, about 20 volunteers joined them, including students from Yreka, Mount Shasta and Forks of Salmon schools.
"It's rather labor intensive," Borok said.
To get the estimates, scientists and volunteers mark carcasses of spawned out salmon found along the river during each sweep. A combination of those numbers and counts of salmon egg beds goes into the formula that leads to the run estimate.
The diminished run numbers on the Salmon came as a disappointment to Nat Pennington, fisheries program coordinator for the Salmon River Restoration Council, a nonprofit group that has been working to improve the river for salmon since 1992.
"We can fix our river all we want, but if they don't do something about the Klamath," then the numbers will continue to drop, he said.
Federal and state officials have been in talks with stakeholders for years trying to find ways to make the Klamath River more hospitable to salmon.
Talk of salmon on the Klamath River inevitably brings up images of September 2002's fish kill, when an estimated 33,000 adult salmon went belly up on the lower portion of the river after freshwater pathogens bred in warm, crowded waters.
Of late, scientists have been focusing on a different culprit, Ceratomyxa shasta, or C shasta, a parasite that causes infections in salmons' intestines. It has been killing young salmon headed through the Klamath River system and out to sea the past several years. Millions of small salmon make the swim and mortality estimates have been in the hundred of thousands, but it is hard to be exact.
"There is no good way to get a handle on them because they are so small," Borok said.
The C shasta parasite spends part of its life cycle in tiny worms that nestle in algae and sand along the river. With the wet winter so far, the same high water that vexed surveyors on the Salmon River could help flush the parasite out of the system and lead to a boost in salmon numbers in coming years.
If the weather turns dry, C shasta could be as thick as it has been over the past several years.
"We don't know the effects of the water conditions until later this year when the fish start migrating out," said Jerri Bartholomew, an assistant professor at Oregon State University's Center for Fish Disease Research. "A lot depends on what we have from now until then." #
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