Killer whales threatened by California's thirst

California's thirst is helping drive an endangered population of West Coast killer whales toward extinction, federal biologists have concluded.

The southern resident killer whale population, which numbers 83, spends much of its time in Puget Sound but since 2000 many of them have been spotted off the California coast as far south as Monterey Bay.

In a draft scientific report, biologists conclude the damage that water operations are doing to California's salmon populations is enough to threaten the orcas' existence since they depend on salmon for food. Federal officials confirmed to MediaNews on Friday the conclusions of the report, which has not been released.

"It does point to the interconnected nature (of problems in the Delta)," said Maria Rea, the Sacramento area office supervisor for the National Marine Fisheries Service.

The findings, contained in a draft report by the agency's scientists, could elevate public support for environmental protection in the Delta, where the conflict between environmental advocates and water users has centered on Delta smelt, a nondescript fish that grows a couple of inches long and smells like cucumbers.

"People have a hard time looking at the Delta smelt for its own sake," said Zeke Grader, executive director of the Pacific Coast Federation of Fishermen's Associations. "If it's Shamu, that's a different thing."

Biologists last month reported tentatively that pumping water out of the Delta threatens to drive spring-run chinook salmon and winter-run chinook salmon extinct.

The orca study found the loss of those fish could leave whales at times with patches of ocean that lack food, Rea said.

In addition, the reliance on hatchery-raised salmon in other salmon runs makes that food source vulnerable to disruption, she said. Hatchery fish lose the natural genetic diversity that is helpful in recovering from attacks of disease or changes in environmental conditions.

As a result, the regulatory hammer of the Endangered Species Act could be used much more aggressively to fix problems plaguing the state's most valuable salmon run, according to Grader.

The Sacramento River fall-run chinook salmon, the backbone of the commercial salmon fishery, collapsed last year. Although the run is not endangered, its collapse led to the unprecedented closure of the fishing season. Grader said regulators could use the tough law to protect fall-run salmon, not because it merits the law's protection by itself but because it provides food for the endangered orcas.

Orcas are the most widely distributed whale in the world and live in all kinds of ocean habitat. Some populations roam the oceans but resident populations, like the southern resident whales in Puget Sound, tend to stay closer to home.

The southern resident orcas' diet is almost entirely salmon and about 80 percent is chinook salmon, said Ken Balcomb, executive director of the Center for Whale Research in Friday Harbor, Washington.

The 83 Puget Sound orcas eat about 500,000 salmon a year, he said.

In winter, the whales move out into the ocean and swim up and down the coast in search of food, a search that in the last seven years has brought two of the three pods as far south as Monterey. Balcomb said that in recent years California's salmon has been an important food source for the whales for six to eight weeks a year.

This year, however, the orcas swam about halfway down the coast of Oregon before giving up the hunt, Balcomb said.

"They got down there and said California is not worth it this year and turned around," Balcomb said.