Salmon Runs Forecast to Be Stronger
By ERIK ROBINSON
Ocean conditions are shaping up for a big salmon return to the Columbia River and its tributaries beginning next year, according to federal scientists.
Rebounding from abysmal conditions in 2005, scientists with the National Oceanic and Atmospheric Administration say they’re finding “very productive” conditions in the ocean north of Newport, Ore. It begins with an upwelling of cold water pulling nutrients up from the ocean depths.
“There’s lots of food, lots of juvenile salmon,” said John Ferguson, a NOAA senior biologist in Seattle. “The water’s cold and it’s productive.”
Conditions are helped by a relatively strong current flowing down the coast from the Gulf of Alaska.
“If it’s flowing strongly from the north – as it is this year – it’s bringing cold water down, and it’s bringing a lot of food for salmon,” Ferguson said.
Scientists are able to take a slew of measurements using government research vessels and data collected from fishermen along the coast. Ferguson said the number of juvenile salmon sampled in the ocean is among the highest in recent years.
Meanwhile, federal dam managers credited improvements in fish passage around Columbia basin dams for playing a role in boosting salmon returns.
Federal officials have reduced mortality substantially since the 1970s. Newer turbines feature smaller gaps where fish are less likely to get pinched; new spillway weirs scoop up fish before they shoot through the turbines; and various bypass systems propel smolts around the dams more safely.
Still, the dams kill plenty of fish.
The Bush administration earlier this year released its latest plan to balance federal dams against the survival of imperiled salmon. In it, federal managers want to limit the number of ocean- bound juveniles killed to between 4 percent and 7 percent at each dam along the river.
Wild salmon emerging from streams in the central Idaho wilderness, for example, must pass eight major dams on their way to the ocean. That means federal dams will kill between 32 percent and 56 percent of the those runs before they ever reach the ocean.
“Juvenile fish-passage survival at main-stem dams has improved and will improve even more,” Rock Peters, a senior fish biologist for the U.S. Army Corps of Engineers, said in a prepared statement .
Erik Robinson covers the environment. Call him at 360-735-4551 or e-mail
erik.robinson@columbian.com
.
Originally published by ERIK ROBINSON Columbian staff writer.
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