More Carp Could Mean Less Ducks

From the story on Oregonlive.com: _Biologist Linda Beck stands in water halfway to her knees, gazing out on a lake … Continued

From the story on Oregonlive.com:

_Biologist Linda Beck stands in water halfway to her knees, gazing out on a lake strangely empty of waterfowl. Cormorants, pelicans, gulls and terns by the millions once wheeled and shrieked above Malheur Lake while ducks bobbed and dove for insects. Now, the lake and sky are eerily empty. “I mean, there are no birds,” said the 35-year-old fish biologist for the U.S. Fish and Wildlife Service , splashing to dry ground on the north shore on a recent afternoon. “We still should be seeing some birds.” There’s a one-word explanation for the dramatic downturn in waterfowl on the shallow 50,000-acre lake 30 miles south of Burns: carp.

Their ranks have exploded over the course of decades — and nothing, not even a succession of wholesale poisonings, has beaten them back for long. Carp out-compete the waterfowl for Sago Pondweed, aquatic invertebrates, insects and other food. They also root on the lake bottom, stirring up sediment and diminishing the sunlight necessary for the growth of lake grasses. “It’s a giant carp pond,” said Bob Sallinger , spokesman for the Audubon Society of Portland . “That lake is basically a dead lake.” Migratory waterfowl, shore birds and colonial waterbirds used to darken the sky above Malheur Lake and the 187,000-acre refuge during their annual stop on the Pacific flyway. Duck production alone averaged more than 101,000 annually with a peak of 139,000 in 1946.

No more. Waterfowl production is down 75 percent at the refuge and visiting bird numbers have fallen by several million a year, according to the Fish and Wildlife Service. The fish invaders have caused problems on the refuge since the 1940s. The federal agency has poisoned the lake and tributaries with an odorless chemical poison called rotenone multiple times in unsuccessful efforts to kill them off, the last time 1992.

Maybe intense fishing could help reduce carp numbers, right? No, because fishing isn’t allowed in the lake…

One solution — fishing — isn’t a possibility for now. The refuge doesn’t allow the public to angle for carp in Malheur Lake. And winning approval would likely be an unwieldy process involving insertion of a proposal in the Federal Register in Washington, D.C., and probably would take two years._

Thoughts? Have you seen a correlation between ducks and carp on your local waterfowling waters?