Tribal hatchery raises sturgeon in bid to stave off extinction

BOISE — Each year, endangered white sturgeon lay millions of fertilized eggs on the silty bed of the Kootenai River in Northern Idaho — in vain.

The white sturgeon, the largest freshwater fish in North America, has not reproduced in the Kootenai since Libby Dam was completed in Montana in 1974, reducing the river velocity and trapping critical nutrients upstream.

Downstream, however, pools at a hatchery run by the Kootenai Tribe teem with thousands of year-old sturgeon, inchlong miniatures of the two armor-plated wild adults in another tank that measure 6 to 7 feet long. Another tank holds the medium-size fish raised at the hatchery since birth.

Bred from captured wild sturgeon, the young sturgeon may be the last hope of saving the species from extinction.

Over the past decade, the hatchery has released 80,000 juvenile sturgeon into the river. But since the fish don't reach sexual maturity until about age 30, the oldest of those hatchery-raised sturgeon are not expected to begin spawning until 2025.

And the number of fish that will survive until that time will be significantly less than 80,000, said Bob Hallock, Kootenai white sturgeon recovery-team leader for the U.S. Fish and Wildlife Service.

"The first year the fish are released, about 60 percent survive," he said. "After that, the rate is about 90 percent annually. So you play that out over 30 years and that's not a lot of fish."

Researchers are unsure whether the hatchery fish will return to the place they were put into the river or spawn elsewhere along the 167-mile stretch of river between Kootenai Falls in Montana across Idaho to Corra Linn Dam at the end of British Columbia's Kootenay Lake, said Sue Ireland, the fish-and-wildlife program manager for the Kootenai Tribe.

An 18-mile section of the river was designated critical habitat for the white sturgeon by the federal wildlife agency. The means federal and state agencies must consult with the agency before undertaking projects in that section of the river that might affect the sturgeon, which was declared endangered by the federal government in 1994.

The habitat designation also means that Libby Dam operations must be modified to better replicate the higher, faster flows of the Kootenai before the dam. It's estimated that will cost $360 million to $780 million between now and 2025 for modifications to the dam and in lost hydropower revenue.

Meanwhile, planners with the Bonneville Power Administration and the Army Corps of Engineers have until April 14 to devise a strategy to stop the steady demise of the estimated 500 remaining wild sturgeon, a number expected to dwindle to 50 by 2030, barring successful spawning by the hatchery sturgeon.