Hatchery destroys diseased Lahontan cutthroats

Sandra Chereb

Thursday, Feb. 3, 2000 | 2:57 a.m.

GARDNERVILLE, Nev. - Hundreds of thousands of Lahontan cutthroat trout were destroyed at a federal fish hatchery Thursday in an attempt to rid the facility of a disease that destroys the endangered game fish's organs.

Biologists at the Lahontan National Fish Hatchery have been struggling since November to treat the fish afflicted with Furunculosis, a bacteria found naturally in northern Nevada watersheds.

"In the wild, the bacteria doesn't generally hurt the fish because it falls off their skin," said Randi Thompson, spokeswoman with the U.S. Fish and Wildlife Service in Reno.

But in the close confines at the hatchery, the disease spread quickly among the dense populations of the threatened species. Some 80,000 fish had died before Thursday's action.

"If left untreated, the bacteria attacks the fish's organs," Thompson said. "You can physically see sores on the skin."

The bacteria dies quickly without a host or when exposed to heat and poses no health threat to humans, she said.

About 300,000 fish were suffocated by an infusion of carbon dioxide pumped into shallow-water holding tanks. The carcasses were taken by Reno Rendering to be turned into fertilizer and feed, officials said.

Bob Williams, field supervisor of the Nevada office of the Fish and Wildlife Service, said efforts to treat the disease through medication failed largely because of the hatchery's recirculated water system.

"The fish are not responding to the medication primarily because we have to re-use about 65 percent of our water," Williams said. "The bacteria that is causing the disease continues to circulate in the system, reinfecting the fish."

Biologists don't know how the fish became infected, but theorize the bacteria was carried by birds from the east fork of the Carson River nearby.

The destroyed fish were supposed to be planted in Pyramid Lake north of Reno.

Hatchery officials hoped to salvage another 200,000 fish earmarked for Walker Lake near Hawthorne by treating them in a freshwater system.

About 100 other fish being studied as part of a Lahontan cutthroat recovery program were held in separate brood ponds and were not affected by the disease, Thompson said.

Elwood Lowery, director of the Pyramid Lake Paiute tribe's fishery in Sutcliffe, said despite the problems at the federal hatchery, anglers shouldn't see a decrease in fish at the popular lake.

"We planted about a million last year and we have 200,000 fish on hand," he said. "There's plenty of fish in Pyramid Lake."

Lahontan cutthroat are listed as a threatened species under the Endangered Species Act. Though protected, they are allowed to be harvested by anglers because of hatchery production programs.