Efforts to save endangered Snake River salmon appear to be pulling the plug on some upstream trout and kokanee fisheries.
Lake Roosevelt was drawn down more than 10 feet last week, putting fish off the bite and worrying biologists who think kokanee and rainbows are being flushed over Grand Coulee Dam.
Idaho Fish and Game Department biologists have fewer doubts.
On Wednesday, the department authorized emergency rules allowing people to salvage kokanee being flushed through Dworshak Dam.
Biologists say the kokanee population in Dworshak is at an all-time high. But once the fish go through the dam’s spillways or turbines, they’re virtually dead meat.
To prevent wasting the dying fish, people can scoop them up by hand or with hand-held dip nets in the North Fork of the Clearwater from the Ahsahka highway bridge upstream to Dworshak Dam.
Fishers still must have a state fishing license and must adhere to the 25-fish daily limit. The salvage rule is valid until Aug. 31.
Dworshak and Grand Coulee dams are being flushed to boost flows in the Lower Columbia where Snake River salmon are trying to make their way to the ocean.
“I have major concerns that the current drawdown to boost passage of endangered salmon will do serious damage to fish in upstream storage reservoirs,” said Al Scholz, Eastern Washington University fisheries prof and consultant to the Spokane Tribe.
Although small numbers of kokanee have been stocked in Roosevelt for eight years, this is the fourth year since the tribal kokanee hatcheries went on line. Since 1991, the hatcheries have been releasing two million kokanee fry a year.
Kokanee generally take four years to mature. The first major spawning returns were expected this fall.
“We know our tagged fish have been showing up downstream in past years,” Scholz said. “This year it could be much worse. Once they go over the dam, they can’t return.”
Dumping water out of Lake Roosevelt also has consequences for the fish that stay in the lake.
On the average, water that enters the top end of the reservoir moves through the pool and out the dam in about 40 days, Scholz said. That compares to an average water retention of 100 days at Libby Dam.
Under current drawdown rates, water may be retained in Lake Roosevelt for only 15 days, Scholz said.
“That affects productivity,” he said. “The reservoir doesn’t maintain nutrients.”
The rush of water through Lake Roosevelt is especially detrimental to plankton eaters such as kokanee and perch, not to mention the fish that feed on these fish, such as walleye and smallmouth bass.
Right now, kokanee are having trouble finding enough to eat.
Kokanee and rainbows are underrated in the piscatorial pecking order to save Snake River salmon because of outdated information, Scholz said.
The U.S. Fish and Wildlife Service is basing its perception of Lake Roosevelt fisheries on a creel census conducted in the early 1980s. At that time, anglers were catching about 1,000 rainbows and only 300 kokanee a year.
Since then, new hatcheries and volunteer net-pen production has boosted the fisheries significantly.
“The kokanee harvest runs from 7,500 to 31,000 a year,” Scholz said. “The harvest of rainbows ranges from 80,000 to 140,000.”
Lake Roosevelt no longer is a local secret.
With salmon seasons closed or curtailed in much of Western Washington, more West Side anglers are heading inland.
Last week, at least two guides who normally would be fishing for spring chinook salmon on the Cowlitz River were launching out of Spring Canyon near Grand Coulee Dam.
The irony and timing of events is discouraging to anglers looking for a silver lining to the salmon woes.
Just when the fisheries are maturing and the demand is increasing for Lake Roosevelt kokanee….
You can contact Rich Landers by voice mail at 459-5577, extension 5508.