Salmon Gene Bank Urged to Save Species : Preservation: Zoologist sees it as an inexpensive way to complement other efforts to rescue the threatened Northwest fish.

One key to saving threatened Northwest salmon species is in the freezer, a researcher says.

Creating a gene bank of frozen sperm from wild salmon does not substitute for reservoir draw-downs and other steps to improve salmon habitat in the Columbia River Basin, said Gary Thorgaard, an associate professor of zoology at the University of Washington. But it is an inexpensive way to at least prevent extinction if those measures fall short, he said.

His proposal comes as fishery managers around the world increasingly are turning to gene banks to save rare species.

In the Northwest, the National Marine Fisheries Service recently declared the Snake River sockeye endangered, forcing the government to act to save it from extinction.

Proposed remedies have raised the ire of everyone from electricity customers to river barge operators who fear the economic costs.

Thorgaard’s proposal may be simpler than others, but it is not easy to collect sperm from rare male salmon as they swim upstream from the ocean to freshwater spawning areas hundreds of miles inland. On top of that, the males produce sperm only once during their life cycle.

Freezing and storing sperm without ruining reproductive viability is another challenge--fertilization with frozen sperm is about half as successful as with fresh sperm.

But Thorgaard, who is a recreational fisherman, is convinced that a salmon gene bank can complement steps to improve habitat. Such a program could also unlock many secrets of fish genetics and pave the way for efforts to save other endangered fish.

“I think we should be looking at this now with the wild fish that aren’t right at the brink (of extinction),” he said.

A few decades ago, thousands of sockeye spawned annually in Redfish and surrounding lakes, about 900 miles from the Pacific Ocean. This year, only four sockeye made it, three males and one female. Last year, none came.

But fisheries managers now are more hopeful. With funding from the Bonneville Power Administration and assistance from Thorgaard and his colleagues, the Idaho Department of Fish and Game has frozen sperm from this year’s three males.

The sperm may be needed as soon as next year, said Keith Johnson, the department’s sockeye program manager.

“We’re buying time . . . until the river conditions improve,” Johnson said. “We need to be able to have fish in the meantime.”

Thorgaard envisions a larger regional program to save threatened salmon species and increase spawning runs.

Collecting sperm would be the most difficult part of the program, he said. Scientists could locate males, anesthetize the fish and collect the sperm, ideally without harming the salmon’s ability to naturally spawn later.

The sperm would be frozen in solution through a process called cryo-preservation and stored.

Scientists rely on sperm because efforts to preserve female eggs have so far been unsuccessful.

Cryo-preservation, which is used for cattle and other species, has been tested for salmon since the 1970s and is in use in Iceland and Norway. In Alaska, similar techniques are being used to save a threatened chinook salmon run.

Thorgaard tailored the technique to Northwest salmon runs with colleagues at the university and with Joseph Cloud, a zoology professor at the University of Idaho.

They have produced hundreds of fish through cryo-preservation at a Washington State hatchery.

“As far as we can tell, the offspring that we make using this procedure are totally normal,” he said. “It’s a well-established sort of approach but it’s just a little bit newer applying it to a fish.”

The cost is cheap, he says. Mixing up solution to preserve the sperm is easy and the liquid nitrogen and storage equipment used during freezing is widely available.

Thorgaard said the costs of a large-scale regional program would probably run a few hundred thousand dollars.

Michael Schiewe, director of the National Marine Fisheries Service’s regional science center in Seattle, said a gene bank program could be invaluable.