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OGALLALA, Neb. – Less than two years after its fish population was completely eradicated, Lake Ogallala, once known as the state^s best trout water, looks to be on the way back.
"We^re seeing some pretty positive results at this point," Monte Madsen, Nebraska Game and Parks Commission fisheries biologist, said of the renovation.
The result can easily be seen on the stringers of fishermen returning to the cold-water fishery nestled below Kingsley Dam and Lake McConaughy. Rainbow trout from 1 to 4 pounds are being caught, some even bigger. The 4-pound fish, Madsen said, are the result the first stocking of three-quarter-pound trout following the renovation.
"They^ve been in there for over a year, but that^s still good growth," he said. "We^re very happy with that. And the fishermen are happy."
Biologists applied more than 12,000 pounds of rotenone, a chemical that kills gill-breathing fish, to the lake in October 1997. The move was necessary to remove rough fish and alewife, which at the time comprised about 80 percent of the lakes fish population by numbers and 90 percent by weight. Alewife compete with trout for zooplankton, which was one factor in the decline of the fishery.
Another factor in the decline was the installation of a hydroelectric plant at Kingsley Dam in 1985. During the summer months, the water drawn from Lake McConaughy through the power plant is virtually devoid of oxygen, something trout need plenty of to survive.
Wide fluctuations of water levels in Lake Ogallala also inhibited the growth of aquatic vegetation necessary for zooplankton production.
Following the renovation, rapidly growing strains of rainbow trout were stocked in the lake. Ten thousand rainbows are stocked each month from March through June and in September and October. Brown trout and chinook salmon, two species that prey heavily on alewife, were also added to keep the population of the alewife that reenter the lake from Lake McConaughy in check.
The Game and Parks Commission also installed an aeration system in the north end of the lake to improve water quality and provide more oxygen for the fish. A second system will start pumping oxygen into the lake^s south end this week.
"We^re seeing a resurgence in aquatic vegetation, which is very important as a carrier of invertebrate and insect life, an important trout food," Madsen said.
Ongoing studies will tell the true story of the project^s success by determining if fish are staying in the lake or leaving through the North Platte River or irrigation canal outlets. The study includes the use of radiotelemetry to track fish and specially-tagged fish that could earn anglers reporting their catch $5 to $100.
The project is being funded through the sale of Aquatic Habitat Stamps, required by all anglers 18 and older, the Federal Sport Fish Restoration Program and the Nebraska Environmental Trust.
Uploaded: 7/29/1999
Uploaded: 7/29/1999