Efforts to help endangered wild Kootenai River white sturgeon reproduce by spilling water over Montana’s Libby Dam in June to entice the fish to spawn in Idaho haven’t been as successful as hoped due to low water conditions, a federal official said.
Jason Flory of the U.S. Fish and Wildlife Service said the river at its maximum level didn’t exceed some past years when water wasn’t spilled over the dam.
“It made some difference, but we didn’t get the river stages that we have seen in past years without spill,” said Flory, the agency’s Kootenai sturgeon recovery team leader. “It’s not surprising we didn’t get a big change in sturgeon behavior in the river. That’s unfortunate, but that’s the way it goes. We worked with what we had.”
Pete Rust of the Idaho Department of Fish and Game said seven adult sturgeon — five females and two males — tagged with sonic transmitters made it to a cobble-and-gravel riverbed spawning area upstream of Bonners Ferry, Idaho, in June.
Rust said four of the sturgeon were in the area before the spill started on June 10 and that lasted seven days, and all seven fish moved downstream of Bonners Ferry by June 30.
“Overall, the test and the planning and execution of it went pretty well for the first year,” Flory said. “The management among the various agencies went very well.”
He said spills are planned again the next two years to try and help the sturgeon.
Before Libby Dam, there were an estimated 10,000 Kootenai sturgeon. Fewer than 500 mature adults of spawning age remain.
The wild Kootenai River white sturgeon, a toothless beast from the days of dinosaurs, has a large head, armor-like scales, can reach 19 feet long and top 1,000 pounds. It takes 20 or 30 years for white sturgeon to mature and reproduce.
An isolated population of the bottom-feeding behemoths lives along a stretch of the Kootenai that passes through Montana, Idaho and British Columbia, Canada. The construction of Libby Dam in 1974 stopped the river from flooding Bonners Ferry, Idaho, but also prevented the high water flows that triggered the sturgeon to move upriver and spawn.