BONNERS FERRY – Four-inch long sturgeon frolicked in a hatchery tank – comically flipping onto their backs to feed, then wriggling right side up.
Barely a year old, they looked ancient. Long snouts, sharklike tails and the sturgeon’s bony armor hinted at the species’ prehistoric origins, which date back 150 million years.
“They’re mysterious, beautiful creatures,” said Sue Ireland, fish and wildlife director for the Kootenai Tribe of Idaho, the hatchery’s operator. “It’s important that we do everything in our power to help them survive.”
As part of aggressive plans to keep the Kootenai River’s white sturgeon population from sliding into extinction, the tribe has crafted a habitat restoration plan for 55 miles of the river. The habitat work will help young hatchery sturgeon survive after they’re released into their native waters, and also benefit the remaining wild sturgeon population.
In the 1970s, an estimated 7,000 white sturgeon lurked in the river’s cool, green depths. Only 800 to 1,000 adults remain – and that figure’s shrinking by about 9 percent each year, according to the U.S. Fish and Wildlife Service.
Scientists believe the next few years will be critical for the Kootenai sturgeon. More than three decades have passed since the fish reproduced successfully in the river. If the trend isn’t reversed soon, only a handful of wild female sturgeon will be left to spawn.
Kootenai sturgeon are a distinct stock, evolving after the last ice age isolated them from Columbia River sturgeon. The freshwater giants can reach 8 feet in length, but they’re slow to mature. The fish don’t spawn until they’re 30. Although females can live into their 70s, they lay eggs only every four to six years.
Dwindling numbers of Kootenai sturgeon were first documented in the mid-1960s. Then came Libby Dam. Sixty-five million years ago, sturgeon survived the mass extinction that killed off the dinosaurs, but they were no match for modern engineering.
Built in 1974 for flood control and power generation, Libby Dam tamed the spring torrents that once triggered the upstream journey of the sturgeon from British Columbia’s Kootenay Lake to spawning grounds near Bonners Ferry.
In recent years, the U.S. Army Corps of Engineers has released water from the dam to mimic the spring freshets. Although the sturgeon are spawning again, the fry don’t survive. In an effort to reverse the trend, the tribe’s habitat plan calls for creating deeper pools in the main river and restoring side sloughs for rearing areas.
“We’re trying to unlock the mystery of what’s keeping them from thriving in the wild,” Ireland said.
The restored habitat will also help five other native fish species, including kokanee, which are part of the sturgeon’s diet.
Ireland said the habitat plan is a practical document. It recognizes that the river won’t return to a pristine state. But by working closely with local landowners, she said, the tribe hopes to mitigate some of the damage caused by a century of diking, farming and other development.
“Society has put constraints on the river,” said Greg Hoffman, a fish biologist who works at Libby Dam. Bonners Ferry would flood if the Army Corps of Engineers released the same volume of spring flow that historically swept down the valley, he said.
“We want to see the system restored, but we’ll do it in a way that’s sensitive to the local community and the culture of the area,” said Patty Perry, the tribe’s administrative director.
The tribe has gathered a policy team that includes representatives from Idaho, Washington, Montana and British Columbia’s Ministry of the Environment. Tribal members will work cooperatively with other governments to secure funding for the habitat work, Perry said.
Sturgeon are culturally significant to the 141-member Kootenai Tribe.
“The tribe is connected to sturgeon just like the Columbia River tribes are connected to salmon,” Ireland said. “They’re a spiritual messenger, revered for their longevity.”
Ireland, who isn’t Native, began working for the tribe in 1996. She, too, fell under the sturgeon’s spell.
“They get to you,” she said, cradling a hatchery sturgeon in her palm.
Everyone who works on the restoration effort develops an intense desire to see the Kootenai sturgeon survive, she said.