Battle brewing over sturgeon.

Byline: From The Register-Guard and news service reports

Another legal battle is shaping up between environmentalists and the federal government over a species in trouble. This time the fight is over green sturgeon, one of 25 species of sturgeon found worldwide.

Environmentalists last week served formal notice on the federal government that they plan to ask the courts to reverse last month's denial of Endangered Species Act protection for green sturgeon, a species that is down to only three known spawning populations - in Oregon's Rogue River and in the Klamath and Sacramento rivers of California.

The lawsuit threat was prompted by last month's announcement by NOAA Fisheries - the agency previously known as the National Marine Fisheries Service - that it would not list the green sturgeon as a threatened or endangered species.

NOAA Fisheries said it could find nothing to indicate the green sturgeon are in decline.

``There is no evidence the population is collapsing, the big fish are being fished out or the size of the stock is declining,'' said biologist Craig Wingert. ``Admittedly, this isn't the best information in the world. But we didn't feel it was enough scientific evidence to show the populations are declining in the face of any risk factors.''

The agency agreed to categorize green sturgeon as a ``candidate species'' and continue to consider new information as it comes in.

Environmentalists say the "living dinosaurs," so called because they are one of the oldest known species on earth, are vulnerable to a catastrophic event.

``All evidence shows that we are at great risk of losing this majestic ancient fish forever,'' said Cynthia Elks of the Environmental Protection Information Center. ``The agency's findings are incomprehensible and will not withstand legal challenge.''

At least three other green sturgeon spawning populations died out, environmentalists say.

``What we do know is the sturgeon has disappeared from as many or more rivers as it persists in as far as spawning populations,'' said Jeff Miller of the Center for Biological Diversity. ``Abundance is not the same as spawning pop- ulations.''

A coalition of conservation groups gave NOAA Fisheries the 60-day notice required before a lawsuit can be filed seeking to reverse the agency's earlier decision on the sturgeon's status.

Coalition members say green sturgeon are threatened by the loss of habitat to dams, logging, agriculture, mining and urban development, and being taken inadvertently by fisheries focused on white sturgeon.

The lawsuit is part of a larger strategy to pressure the government to devote more water to fish in the Klamath River, instead of diverting it for agricultural irrigation. A long-running battle over Klamath River flows came to a head in 2001, when drought conditions led the U.S. Bureau of Reclamation to severely reduce water to farmers on a federal irrigation project to leave more water for federally protected suckers and salmon.

"These fish need big, deep rivers, and our concern is the way the Klamath River has been managed, that has not been good for sturgeon,'' said Wendell Wood of Oregon Natural Resources Council.

Some green sturgeon and an estimated 33,000 salmon died in the Klamath last year when flows were reduced to provide irrigation water.

The threat of a lawsuit comes on the heels of a new study published by a researchers from the Bronx Zoo-based Wildlife Conservation Society.

Using radio-tracking techniques, the researchers found that once green sturgeon enter freshwater rivers to spawn, they spend long periods of time in extremely small home ranges.

Sometimes a number of individual sturgeon share a pool measuring only 50 yards by 50 yards.

This concentration of spawners makes the green sturgeon particularly vulnerable, the researchers said.

"This study shows that green sturgeon can easily become the victims of human exploitation and habitat loss," said the study's author, Wildlife Conservation Society biologist Dan Erickson.

Like salmon, green sturgeon are born in freshwater rivers and range around the Pacific before returning to their home rivers to spawn.

They go as far south as Mexico and as far north as the Bering Sea, and congregate in summer in Grays Harbor and Willapa Bay in Washington and the Columbia River estuary between Oregon and Washington.

They no longer spawn in California's Eel and South Fork Trinity rivers and are believed to be gone from Oregon's Umpqua River. There is debate over whether they ever spawned in California's San Joaquin River.

Mature fish can reach 7 feet long and live more than 40 years, spawning every three to five years between March and July, when females deposit up to 140,000 eggs each in deep pools in large rivers. They feed on small shrimp, shellfish and fish.

CAPTION(S):

Matt Howell, a biologist with the Oregon Department of Fish and Wildlife, holds a captured green sturgeon, which the federal government has refused to list as threatened or endangered.