October 27, 2007 in Idaho

Lakebed will be ready just in time for spawning

By The Spokesman-Review
 
Jesse Tinsley photo

Diver Mark Cobb waits for others to turn on pumps Friday in Bayview. Associated Underwater Services will vacuum silt off the lake’s bottom, leaving exposed gravel, the preferred surface for kokanee spawning.
(Full-size photo)

Fast fact

Kokanee form the backbone of a $17 million sport fishery on Lake Pend Oreille.

BAYVIEW, Idaho – Just in the nick of time, Lake Pend Oreille’s kokanee salmon should again have a clean bed of gravel for fall egg-laying.

The gravel beds and tens of thousands of fertilized eggs were smothered by silt in April as a result of an expansion project at the Harborview Marina in Bayview. The work was illegal, officials say, and likely wiped out a large portion of this year’s class of native kokanee on Lake Pend Oreille.

After weeks of delay, work began Friday to vacuum the silt off the spawning gravels. Associated Underwater Services of Spokane has been hired by the marina owner, Bob Holland, to conduct the cleanup.

Pressure was building on Holland to complete the work. He had already missed a deadline of Oct. 1, and the first spawning kokanee are expected to return to the site in less than two weeks, according to officials with Idaho Fish and Game.

“The window is closing fairly rapidly,” said Fish and Game’s regional director, Chip Corsi.

The first kokanee was spotted on the spawning beds last year on Nov. 7. That’s the new deadline for the work to be finished. Corsi said losing another year-class of the already imperiled fish is unacceptable. “We can’t afford that.”

Divers will use a vacuum-like device to suck silt and sand off about 16,000 square feet of spawning beds, said Dennis Scott, who works for Holland’s company, Waterford Park Homes. The divers will be working up to 12-hour shifts and over the weekend to accomplish the task. The company expects to spend at least $150,000 to address the problem.

Although the work is moving forward, officials with Waterford Park Homes have disputed whether Harborview Marina is any more covered in silt than other marinas in the area, Scott said.

The company has surveyed spawning sites in front of two other marinas and found more silt covering these places than what has settled onto the gravels at Harborview, Scott said.

Once the silt and sand is vacuumed from the lake bed, the slurry will be pumped to a settling basin about 100 feet from the shore.

The water is expected to leach back into the lake, leaving the fine particles in the basin, Scott said.

Kokanee form the backbone of a $17 million sport fishery on Lake Pend Oreille, but the fish numbers have been plummeting in recent years because of spawning habitat loss and predation by exotic rainbow and lake trout.

Although the spawning site near Bayview covers only a tiny fraction of the lake bottom, it’s one of the last kokanee spawning strongholds in the lake, Corsi said.

The area is believed to be a good spawning site because it’s where water from the lake flows through the gravel into the Spokane Valley-Rathdrum Prairie Aquifer. The flow of water nourishes the eggs with oxygen and keeps them free of silt.

In April, just as tens of thousands of kokanee eggs were beginning to hatch at the site, they were crushed and smothered.

Holland did not have a permit to have the work conducted, officials said. Not only were steel pilings pounded through the spawning beds, but the propeller wash from a construction barge turned the area in a stew of mud and fish eggs.

Idaho Fish and Game estimated the loss of the eggs and fry to be worth $1.4 million. Holland has since been fined $2,500, which is the maximum under state law.

The U.S. Army Corps of Engineers and the Idaho Department of Lands have also suspended pending construction permits for the marina.

Brad Daly, regional regulatory chief for the Corps of Engineers, said his agency is reviewing a new construction permit for the marina.

Any work that’s done will have to be friendly to the kokanee, Daly said.


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