FWP presents walleye plans for Fresno lake
The fishery at Fresno Reservoir could rebound to a very healthy status in a few years if the water level remains high enough, a state fisheries biologist said Monday night.
"We've gone through an absolutely devastating series of droughts," said Kent Gilge, Havre fisheries biologist for the state Department of Fish, Wildlife and Parks. "You don't have an instant walleye fishery. You don't have an instant northern pike fishery. It takes a few years to build the forage back."
Gilge spoke at a public meeting co-sponsored by FWP and the Fresno Chapter of Walleyes Unlimited at the Holiday Village Shopping Center community room. Gilge and Bill Wiedenheft, FWP regional fisheries manager at Glasgow, talked to about 30 people at the meeting.
Mike Barthel, president of the Fresno Chapter, said FWP needs to stock walleye in the reservoir. At a tournament last year, 1,872 hours of fishing resulted in 378 fish being caught, he said.
"To get that catch rate up, we're going to need some fish," he said.
FWP has not stocked Fresno with walleye since 1998.
Barthel said that after heavy rainfall in early June, the forage for walleye seems to have increased enough to support adding walleye to the lake.
Gilge said the studies FWP has done to evaluate forage for walleye say otherwise.
"If we put fish on top of what we have now, we're in trouble," he said. "There is not a good situation out there. It is insane to add more fish to a population that is starving to death and declining."
The low water level in the reservoir, caused by several years of drought, has stymied the reproduction of yellow perch, the main food source for walleye from June through March, Gilge said. A secondary source is spotted shiners. From April to June, walleye mostly feed on a mayfly that lives in the mud, he said.
The mayfly population also has been hurt severely by the drought, but insect populations usually recover by themselves in a few years, Gilge said.
When the reservoir is drawn down to supply water to cities and irrigators on the Milk River east of Fresno, it also washes millions of forage fish out of the reservoir, he said.
The drought has had an effect on the number of forage fish, he said. The water level in the winter of 2001-2002 was "probably the lowest it's ever been since we started stocking walleye in the '50s," he said.
Last year, the seines used to catch and analyze the number of forage fish caught only "a handful of perch," Gilge said.
Fresno's water level dropped to 6 percent of its average level on April 3 last year. In the previous year and a half, the levels ranged from 84 percent to 12 percent of the average.
The water level jumped to 117 percent of average within a few days of the rainstorm in early June. It's now 147 percent of the average for this date.
Gilge warned that the level may not stay that high, depending on this year's weather and the low water table caused by the drought.
FWP has stocked prespawn adult perch in Fresno for the last two years, he said, but the water level didn't rise enough by spawning time to allow the population to expand. Perch spawn in April.
FWP's plan for the next few years is to transplant prespawn perch to the reservoir, to do "everything possible to get that perch population up and running," Gilge said.
The plan includes transplanting available rainbow trout to the reservoir to take advantage of the low number of predatory walleye and northern pike, he said. FWP planted trout and kokanee salmon in the reservoir last year.
Then the department will assess the number of forage fish, the walleye reproduction rate and the water level in late July and August. If those numbers are right, FWP plans to stock up to 10,000 walleye fingerlings, Gilge said. The plan, probably without the trout stocking, would be repeated for the next few years.
Members of the Fresno Chapter expressed concern that the trout FWP is putting in the reservoir will compete with the walleye and keep their numbers low.
Gilge and Wiedenheft said the trout and walleye don't compete for the same food source. Trout feed mainly on plankton and insects, they said.
Gilge said the trout don't eat the mayflies when they're in the mud. He isn't sure how the walleye manage to get the insects out of the mud and eat them, he said.
Barthel referred to several FWP documents that he said show FWP planned to stock Fresno with walleye over the past several years. He asked why FWP didn't implement the plans.
Gilge said FWP has followed the management plan for Fresno set in 1997 after the state implemented a warm-water fishing stamp fee. That plan is to stock walleye fingerlings in alternating years depending on an evaluation of the reservoir's conditions. The conditions haven't been right, he added.
Gilge said a certain water level is required to keep the walleye healthy. He said he has urged the U.S. Bureau of Reclamation to maintain a high enough water level, without success, for most of his 27 years in Havre.
Fresno Dam was built in 1939 as part of the Milk River Irrigation Project. The dam is still managed to store water for irrigation and flood control.
Opportunities are arising that could require a minimum level be kept at the reservoir, Gilge said. The Fort Belknap Water Compact, detailing the water rights of residents of the Fort Belknap Reservation, could be used to require a minimum level in the reservoir, he said.
The plan to rebuild the St. Mary diversion, which diverts water to the Milk River, also could require minimum levels, he said. When federal money is used for water projects, the money usually comes with requirements set by the U.S. Fish and Wildlife Service, he said.