Trout surviving drought — barely

By Perry Backus of The Montana Standard - 03/11/2005

DILLON — For years, Clark Canyon Reservoir has been known among anglers as a place where you could catch big trout.

Even after years of drought, the reservoir still holds some big fish n only these days anglers have to really work to catch one.

Trout numbers have plummeted to record lows in the reservoir that once attracted anglers from all over the country. Just a few years back, anglers put in nearly 50,000 days plying its waters in search of rainbow and brown trout that could top the scales at 10 to 11 pounds.

Since then, angler pressure has plummeted at about the same rate as the reservoir's shoreline.

Fishermen numbers dropped last year to an all-time record low of 15,000 angler days, said state fisheries biologist Dick Oswald.

Back in its heyday, nearly half the fishing pressure came from out-of-state anglers. Nowadays, non-residents only amount to about 10 percent of the fishing pressure, Oswald said.

The drought has made it difficult to access the reservoir. By June 1, the pool is low enough that the only place to put a boat in is a steep emergency ramp near the dam. The marina has been closed for years. The campgrounds scattered around the reservoir are left high and dry.

And anglers are spending more time to catch the fish. Last year, on average, it took fishermen more than an hour to land every fish they took from the reservoir.

The good news, "if there is any," is the size of the trout that anglers are catching is still relatively large, said Oswald. During a recent ice fishing derby, fishermen had to bring in trout in the six and a half pound category to be in the running for top prizes, he said.

"We're clearly aging out of those," he said.

The bad news is that there may not be many left in the reservoir to replace those older fish. The last plant of rainbow trout that took hold was in 2001 and that is "what's carrying the fishery to date," Oswald said.

The last three years' attempts failed.

Oswald samples the reservoir each year using gill nets. In 1998-99, when the water levels were good in the reservoir, he was catching about 14 rainbow and nine brown trout in the nets.

This year, those numbers plummeted to 1.2 rainbows per net set and two brown trout.

"The wild recruitment of brown has been horrible as well," he said.

The crash at Clark Canyon has impacted the state's hatchery system, which at one time depended heavily on eggs harvested from the large rainbow trout spawning in the Red Rock River.

"It's been a very significant loss to the hatchery system," Oswald said. "The reservoir used to produce a half million eggs that were used to plant fish in reservoirs all over the state." Oswald plans to stock the reservoir with about 150,000 Eagle Lake Rainbow fingerlings sometime in May or June. As the older fish start to die off, the resulting reduction in competition and predation may help the smaller fish survive, he said.

The one bright spot may be found upstream in the Centennial Valley. The Lima Water Users chose to store their water in Lima Reservoir last summer. That part of the county has also been the most fortunate in getting precipitation last fall and through the winter months.

"Right now, it's the only good spot in this part of the state," said Oswald. "The snow pack in the Centennial Mountains is above 100 percent. It may be the place where the recovery at least gets started." Clark Canyon still has a long ways to go to get back to the good old days. Last fall, the reservoir started with 10,000 more acre feet of water than it did the year before. Over this long dry winter, it's lost half of that advantage.

And downstream irrigators typically depend on runoff from Grasshopper Creek to supply much of their early needs. This year officials aren't expecting much of a runoff at all from that area.

"Whatever happens this spring and summer will dictate on what kind of gains we might see in Clark Canyon," Oswald said. "It certainly doesn't look good right now."