A daily compilation of significant news articles and comment
May 20, 2008
3. Watersheds –
75,000 smolts die in transit
Almost half the salmon haul didn't make it to the coast
Redding Record Searchlight – 5/20/08
By
About 75,000 of 180,000 young fall-run Chinook salmon being hauled in tanker trucks from
Coleman National Fish Hatchery in
"We are kind of in the stages of trying to figure out what went wrong," Scott Hamelberg, the hatchery's manager, said early Monday afternoon. "It's part of the risk of trucking fish."
About 41 percent of the smolts being trucked Monday died.
Scientists plan to perform necropsies -- animal autopsies -- on some of the dead smolts to determine their cause of death, said Alexandra Pitts, spokeswoman for the U.S. Fish and Wildlife Service in
"They are going to see what they can see in them, which can tell them a lot more of what happened," she said.
It was likely a problem with the oxygen level in the fish's water that caused their deaths, Hamelberg said. The 2,500-gallon truck carried about 100,000 fish.
A second, smaller tanker truck got its load of the 6-month old fish to the bay unscathed, he taken such a drastic step, one that is jeopardizing the $150 million West Coast salmon industry.
Unfavorable ocean conditions, habitat destruction, dam operations, agricultural pollution and climate change are among the potential causes.
Historically, 1 million to 3 million chinook salmon spawned annually in the streams that tumbled out of the western
Yates' research projects that an increase in air temperature of 3.6 degrees to 7.2 degrees Fahrenheit could be lethal for the young winter-run and spring-run salmon in the
Studies have shown that high water temperatures have wide-ranging and potentially fatal consequences for salmon, who generally need water temperatures lower than 68 degrees when they return to fresh water. It reduces their swimming ability, increases their vulnerability to disease and leads to lower growth rates. Spawning females require even colder water of 57 degrees for their eggs to live and juvenile salmon migrate back to the ocean more successfully when the river is no more than 64 degrees.
Higher water temperatures can be offset if federal water managers preserved the cold water stored behind Shasta Dam, near the head of the
Thanks to an $80 million temperature control device installed in 1997, the managers of Shasta Dam at the U.S. Bureau of Reclamation already are tweaking flows down the river to keep them cooler, said Larry Ball, operations chief for the Bureau's Northern California Area Office.
"We try to optimize the use of the cold water pool of
The giant metal device bolted to the dam allows flows to be drawn from the lake's deep, cold water, he said.
Such management of cold water is not an option on rivers that aren't dammed.
"Very pristine places are probably more vulnerable to climate change because we don't have the knobs to turn to manage them," Yates said in an interview with the AP.
Releasing cold reservoir water for salmon at certain times of the year would require a shift in strategy regarding how the state's water is apportioned for farmers and some 23 million Californians.
Reassessing how
"We need to take a step back and look at how we're going to manage water in a more comprehensive manner and save salmon," said Mindy McIntyre, a water specialist at the Planning and Conservation League.
State scientists say climate change could lead to more winter flooding, summer droughts, warmer rivers and streams, and rising seas that will push salt water farther upstream from
Temperature spikes are particularly worrisome for cold water fish, such as salmon, steelhead and the state fish, the
The state and federal governments operate 40 dams and reservoirs that were built primarily between the 1930s and the 1970s to tame
Construction of Friant Dam north of
"Fish are the ones that don't have a voice," said Amanda Staudt, a climate scientist at the National Wildlife Federation. "We're not saying those other uses aren't important, we just need to ensure fish are in the mix."
Farmers and cities that depend on
That's in part because of a federal judge's directive last year that state and federal water managers restrict pumping out of the Sacramento-San Joaquin Delta by as much as 30 percent. The cutback was ordered to protect the threatened delta smelt.
Those pumping restrictions, coupled with last year's drought and dry conditions in March and April, have left the state's reservoirs lower than normal. As a result, water deliveries have been reduced significantly.
The cutbacks have increased calls by Central Valley farmers, the Los Angeles Metropolitan Water District and water managers in the San Francisco Bay area to build more dams and consider sending fresh water around the delta by canal or underground pipe.#
http://www.redding.com/news/2008/may/20/75000-smolts-die-in-transit/
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