U.S. District Judge Oliver W. Wanger of Fresno issued an opinion acknowledging the damage to fish populations which appears to be caused by California's water operations, but did not take action. However, the ruling means that regulators will have to take into account the protection of "Central Valley's winter- and spring-run salmon, as well as the remnants of its once-thriving steelhead," when issuing the next permit in March 2009.

The same judge, in April, rejected a study backing increased water exports from Northern California, ruling that water regulators did not properly consider the effects of global warming and other environmental issues that could harm endangered California salmon and steelhead. The judge concluded that the plan was a "total failure to address, adequately explain, and analyze the effects of global climate change on the species."

The study supported increased pumping of water from the Sacramento River Delta to cities and farms situated in Southern California. The delta represents the natural habitat of the Chinook salmon, which provides around 70 percent of Oregon’s salmon catch.

Last year, the numbers of Sacramento salmon dropped dramatically and, even though there is not confirmation yet, scientists say that the delta’s deteriorating conditions cause the salmon to be more vulnerable to poor ocean conditions. The pumping of water from the delta, environmentalists warn, is robbing fish of the water they need to survive.

Last year, a federal court ordered the quantity of water pumped from the delta to be reduced with 30 percent, in order to protect the smelt. In April, federal fishery regulators decided to ban salmon fishing along the California coast to prevent another salmon shortage.