BAYVIEW - Idaho Department of Fish and Game biologists admit they weren't sure if the spawning habitat project on Lake Pend Oreille would draw in kokanee.

But after the first spawning season, the kokanee jury has its verdict.

"They took advantage of it," Andy Dux, Fish and Game's principal research biologist, told the Idaho Lakes Commission on Tuesday.

Dux flashed a photo of scores of spawned-out kokanee collecting along the shoreline onto a projection screen, leading to gasps of delight and approving murmurs by the commission and the audience.

The project at Idlewilde Bay is the result of more than 20 years of research to better understand the spawning requirements of Lake Pend Oreille kokanee, which deposit the eggs in the shoreline gravels.

The project is rooted in the notion that kokanee eggs are three times more likely to survive and hatch out in the spring in areas of the lake where there are "downwelling" currents. Those currents, which charge the Spokane Valley-Rathdrum Prairie Aquifer, can be found at Idlewilde and Scenic bays.

However, those bays have large rocky substrate that's too big in which for kokanee to spawn. To surmount that obstacle, biologists developed a project to distribute smaller gravels atop the rocks.

Fish and Game stockpiled locally-sourced gravel at Idlewilde and used a front-end loader to fill a hopper. A conveyor belt carried gravel from the hopper to a belly dump truck trailer on a barge with a slot in its deck.

Buoys were placed in the water to guide the placement of the gravel.

"We calculated the speeds to get the proper spread rate, trip the gates on the belly dump and that gravel would get spread in the water just like you might see on a highway project. It was a pretty slick way to do it," Dux said.

The result: a 4- to 6-inch layer of gravel in a shoreline area that will stay submerged even if the lake is drawn down to its lowest winter pool elevation. The size of the gravel ranges from a quarter of an inch to three-quarters of an inch, Dux said.

Underwater video footage also confirmed that kokanee are using the project area.

Fish and Game has spread 1,300 cubic yards of gravel and ultimately plans to deposit a total of 3,900 cubic yards by 2016. The deposits will be concentrated at the south end of the lake.

More than nine million eggs were collected from spawning kokanee at Granite Creek this year, according to Fish and Game. An estimated 200,000 spawners were in the fish trap and more were still heading upstream - some of the most robust numbers since the population began crashing in the 1990s.

Lakes Commissioner Brent Baker asked how the current numbers looked in a historical context. Dux said they are comparable to figures from the 1970s.

"You would have to go back to the '50s and '60s to get back to some of those times where you had millions of kokanee," said Dux. "But we're still getting back into a realm where it's not that farfetched."