California's vast network of reservoirs - which destroyed more than 5,000 miles of salmon habitat when their dams were erected decades ago - could turn out to be a savior for a species on the brink of collapse, according to a newstudy. Those dams store cold water, which the study says will be vital to the salmon's survival as climate change is expected to warm California's rivers."Paradoxically, the very thing that is constraining fish now, we could use those to our advantage," said study author David Yates, a project scientist at the National Center for Atmospheric Research in Boulder, Colorado. The peer-reviewed paper will appear in a future issue of the Journal of Climatic Change. It comes at a time when the number of salmon returning to spawn in Central Valley rivers, which are crucial to the West Coast stocks, are at historic lows.

Earlier this month, federal fisheries regulators recommended that fishing along California's coast and most of Oregon be suspended for the year. It was the first time the Pacific Fishery Management Council had 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. Federal authorities declared the West Coast ocean salmon fishery a failure Thursday, a move that opens the way for Congress to appropriate economic disaster assistance for coastal communities in California, Oregon and Washington. 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 Sacramento River. The increase in water temperatures would vary depending on the depth and flows of the river. Higher water temperatures can be offset if federal water managers preserved the cold water stored behind Shasta Dam, near the head of the Sacramento River, and released it when the salmon head upriver. Salmon that once headed far upstream to cooler, mountain streams are now forced to spawn in valley waters because the dam blocks their path.