Pressure on Locallyby Lisa Stiffler
Millions of dollars are being spent to save Northwest salmon and the pressure is on local scientists to determine the most effective ways to accomplish this.
Ten years ago, research focused on dams and hatchery fish, but with 25 West Coast salmon and trout in peril of extinction, the science has grown to include detailed examinations of stream habitat and the impact of the entire watershed.
"We're simply trying to understand what are good areas for salmon," said Dr. Bob Bilby, the Watershed Processes program manager at the National Marine Fisheries Service office in Seattle. It might sound easy, he added, but it isn't.
Salmon are born in streams, travel through estuaries, spend time growing in the ocean and return to their native waterways. The needs of the fish change as they grow and migrate, and different salmon species have unique requirements.
"It's difficult," Bilby said. "It's all connected. You've got to look at it as a continuum."
At the National Marine Fisheries Service in Seattle, about two-thirds of the 250 researchers are devoted to salmon.
"That's how important it's become," said Dr. Michael Schiewe, director of the fish ecology division for the NMFS in Seattle.
There are studies tracking returning salmon by planting devices under their skin so they can be "scanned" by detectors as they pass through dams.
Scientists are trying to improve the health of hatchery fish by raising them in tanks with a more natural habitat including rocks and live food. Healthier hatchery fish are less likely to spread disease to wild salmon.
Scientists are tracking nutrients from the dead salmon as it travels in the food chain. Fish carcasses provide food for insects, which in turn feed the salmon's offspring.
"It's kind of a feedback loop," Bilby said.
George Pess, a stream ecologist, has studied the effect of large logs in salmon habitat. Placing the logs in waterways creates pools that some species of salmon like to linger in, provides cover from predators and controls the flow of sediment.
Pess has also studied the areas adjacent to salmon streams.
In 1998, he found that wetlands -- like those created by ponds and beaver dams -- had a positive effect on nearby salmon streams. In response to his findings, officials in a Puget Sound-area county considered limiting trapping to encourage the return of beavers, but a measure to study the idea was defeated by the county council.
The issue was too politically and socially sensitive, Pess said.
"I can give you information, but I can't make it happen," Pess said.
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