Oversized minnow continues to pose problems at Spooner

RENO - It's a member of the minnow family, but it's a hefty minnow averaging 8 inches. And it's competing with trophy trout in scenic Spooner Lake east of Lake Tahoe.

Three years after the lake was partially drained in a failed attempt to kill off a stubborn population of Lahontan tui chubs, the Nevada Division of Wildlife is trying to figure out what to try next.

Spooner, located off U.S. 50, is supposed to be a catch-and-release lake for trophy trout. But the lake's trout are constantly at odds with the tui chub, which gobble up the same aquatic invertebrates, plankton and flies that trout need.

The result is a trout population that is something less than trophy size. Cutthroat and rainbow trout are stocked in the lake in large numbers but the adult fish being pulled from the water are generally 10-12 inches long, said Pat Sollberger, a fisheries biologist for the state.

Anglers are also saying the fish are rather skinny.

''What is trophy for most people? For many it's 20 inches and we've never come close to that. The chub is the obvious problem,'' Sollberger said. ''They're just way too abundant.''

The problem has been recognized for years but the most dramatic attempt to correct it occurred in 1997, when biologists took advantage of plans by Nevada State Parks to lower the lake level to repair the lake's retention dam.

As the water level lowered, biologists figured, most of the lake's fish chubs and trout alike would swim out the outflow stream and into Lake Tahoe. Those left behind would die in an oxygen-starved environment beneath the lake's winter ice cap.

After water levels rose the following spring, Spooner could be restocked with trout, which would flourish in a lake free of grub-robbing minnows.

It didn't work. When biologists returned in 1998, they found a healthy population of chub, many of them quite large. The fish may have survived by hanging out near oxygen-rich springs bubbling at the lakes bottom.

The options being studied now are lowering the lake even further than in 1997, draining it completely or treating it chemically.

The latter could be a public relations nightmare. Because Spooner Lake is located in the Lake Tahoe Basin, use of chemicals could generate significant concern due to the basin's environmental sensitivity.

And, controversy over California's 1997 poisoning of Lake Davis in Plumas County to rid the lake of predatory pike remains an issue that won't go away.