A federal judge on Wednesday 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, Oliver W. Wanger, of Federal District Court in San Francisco, said the study was scientifically inadequate.

"There is no analysis of adverse effect on critical habitat," Wanger wrote, referring to the chinook salmon.

According to the Mercury News, 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.

Earlier this month, federal fishery regulators decided to ban salmon fishing along the California coast to prevent another salmon shortage.

The agencies that prepared the rejected study said they would prepare another one next year.

Wanger planned a hearing on April 25 to debate how the delta should be managed until the publication of the new study.