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UI Researchers' Genetics Work Essential To Sockeye Restoration

by Bill Loftus
Newswise, September 13, 2002

STANLEY, Idaho -- DNA analysis by University of Idaho researchers is an essential component in a cooperative endangered species rescue program to restore sockeye salmon to central Idaho's Redfish Lake.

Efforts by the Shoshone-Bannock Tribes, Idaho Fish and Game Department, National Marine Fisheries Service and university have brought ocean-going sockeyes back from the brink of extinction.

U.S. Agriculture Secretary Ann M. Veneman and Idaho Gov. Dirk Kempthorne visited Redfish Lake Thursday to celebrate the cooperative program's 10th anniversary. This is the third year the governor has joined the release of adult sockeyes to the lake.

The university's Center for Salmonid and Freshwater Species at Risk near Hagerman, Idaho, supports an unprecedented species rescue program.

"This program involves federal, state and tribal collaboration and has literally saved these unique Idaho fish from extinction," Kempthorne said. "While we are not out of the woods yet, significant strides have been made on all four components of the sockeye program over the past 10 years."

"I can say with relative certainly that without this intervention the Idaho sockeye would now be extinct," the governor said.

"The program as it exists now is essentially a gene-rescue program," said Madison Powell, the center's director and an assistant professor at the UI Hagerman Fish Culture Experiment Station.

The center's sophisticated gene-sequencing equipment allows those running the sockeye program access to what is essentially real-time genetic testing.

The university purchased much of the equipment, which is valued at more than $750,000, through grants and contracts. The Idaho Experimental Program to Stimulate Competitive Research (EPSCoR) project funded by the National Science Foundation played a lead role in the center's development, Powell said.

The genetic testing equipment also helps advance UI efforts to support southern Idaho's diverse aquaculture industry. Idaho raises more than 70 percent of the nation's rainbow trout sold in commercial markets.

For the sockeye program, when an adult fish returns from the ocean it can be tested to determine its genetic background. The genetic heritage of sockeye reared in hatcheries is also known.

The adults in the hatchery are then spawned to ensure the broadest possible gene pool. "We cross them according to their coefficient of kinship. We can do that because we have gene sequencing equipment on site and can do it real-time," Powell said.

The cooperative program to restore the Redfish Lake sockeye started with the offspring of six females, the Eves of the last sockeye run to migrate up the Snake River. The run was classified as an endangered species in 1991 by the National Marine Fisheries Service. It was the first salmon run so listed in the U.S.

Those six maternal lines have since narrowed to three, Powell said, through the simple random chance of survival during their difficult migration to the ocean and the three years they typically spend in saltwater before returning.

Fewer than one in 1,000 young sockeyes that leave Idaho waters will return as an adult.

For sockeyes, like all Pacific salmon, spawning is their final act. The 4- to 5-pound fish return to Redfish Lake nearly depleted from their migration and the rigors of preparing to spawn.

This fall, more than 140 adult sockeyes are expected to cruise the shorelines of Redfish and nearby Alturas and Pettit lakes. That is more than all the sockeyes counted at the lakes during the entire decade of the 1990s.

This year's run includes 11 adults already captured for testing; two of them were spawned in the wild, a first since the program began. Another eight adult sockeyes have been spotted near fish traps. The adults will be released in Redfish Lake and allowed to spawn naturally.

In 1992, only one sockeye, a male dubbed Lonesome Larry, completed the journey. In other years, no adults returned. By freezing sperm, each returning male was tapped to fertilize eggs from several years.

Redfish Lake, perched at 6,500 feet elevation in Idaho's Sawtooth Mountains, was named for the red-bodied, green-headed spawning sockeye that once crowded its waters. The fish were so thick a commercial fishery developed in the late 1800s.

The sockeye run soon dwindled to a few thousand or hundreds of fish. When the species' dire straits became apparent, tribal, state and federal biologists decided the sockeye's last hope lay in a hatchery-based breeding program.

Then, young fish were captured as they left Redfish Lake on a 900-mile river journey to the Pacific Ocean. The handful of adults that returned from the arduous migration were likewise captured and spawned.

Powell and UI researchers have been key to tracking the families and running a "stud book" of sorts for the fish, and doing the genetic testing on the fly.

"This is the only real-time monitoring program of its kind," Powell added.

More information is available at:

Bill Loftus, UI science writer
UI Researchers' Genetics Work Essential To Sockeye Restoration
Newswise, September 13, 2002

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