Thursday, May 28, 2009

Smelt operations a hedge against extinction

By Dylan Darling
Thursday, May 28, 2009
Scientists at the Livingston Stone National Fish Hatchery are studying the Delta smelt, learning how to breed the fish in captivity in case the wild population suffers a crash.

If the fragile Delta smelt winds up going extinct, the species could be restored where the Sacramento and San Joaquin rivers merge using a population being bred in the north state.

Scientists at the Livingston Stone National Fish Hatchery, a small operation nestled on the Sacramento River close to Shasta Dam, have reared the fish since last year. There are now 1,400 of the tiny fish at the hatchery, and the goal is to create a stock of thousands.

The project is expected to continue while the smelt remain in danger of sliding into extinction, said Scott Hamelberg, hatchery manager for the U.S. Fish and Wildlife Service.

"We are all, of course, keeping our fingers crossed, hoping that doesn't happen," Hamelberg said.

Although the hatchery's crew members have mostly worked with winter-run chinook salmon that can be more than 30 inches long and weigh more than 30 pounds, they've learned how to handle the smelt. The small fish usually grows only to 3 inches in length, weighs a couple of grams and usually lives for about a year or two.

"You just do everything smaller," said John Rueth, assistant manager at the hatchery. "They are actually very similar to salmon."

Spawning the smelt requires squeezing eggs out of the females and sperm out of the males. Although, unlike with salmon, Rueth said the work on the smelt requires tweezers.

Also unlike the salmon, the smelt accumulating in the tanks at the hatchery are not for release, he said. Instead, they and another population being bred by University of California at Davis researchers in Byron are being held in case the wild population completely disappears.

Having the smelt living about 200 miles from the Delta at Livingston Stone allows the population here to also serve as a backup for the Byron stock in case there is an earthquake, power failure or other problem that kills the fish, said Bob Clarke, fisheries program manager for the Fish and Wildlife Service's regional office in Sacramento.

"You don't want to put all your fish in one spot," Clarke said.

The agency has two hatcheries in the state, Livingston and Coleman National Fish Hatchery near Anderson. Because of the problems with the smelt, the green sturgeon and Sacramento perch, the agency is considering building a new hatchery in the Delta, Clarke said.

He said a new hatchery could cost as much as $20 million, but it could be years before it's built.

In the meantime, the smelt safety net will stay in the north state.

"For years, they'll be breeding (the Delta smelt) at Livingston Stone," Clarke said.

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