Fish invaders causing dramatic downturn in birds at eastern Oregon refuge

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Dan Morris , a U.S. Fish and Wildlife Service worker on the Malheur National Wildlife Refuge in Harney County, holds a 6 1/2 pound carp. "He put up a good fight," said Morris, who snagged it using a spinning outfit with corn for bait. A population explosion of carp in the refuge's 50,000-acre Malheur Lake is driving off the millions of waterfowl the refuge is famous for.
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BURNS -- 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."

...The federal agency has a new working group of experts to weigh other possibilities. They include commercial harvesting and processing the carp for a variety of uses:

-- Consumption by Russian Orthodox Church believers, for whom carp is a traditional food. U.S. anglers often regard carp as a "trash fish," complaining the meat is bony and oily, but "I had some that was smoked and I loved it," Beck said.

-- Organic fertilizer.

-- Feed for chickens, cows, swine and fish.

-- Alternative energy fuel.

-- Removal of carp pituitary glands for injection into other fish species to accelerate sexual maturity and aid spawning. One gram of diluted carp pituitary can bring $350, Beck said.

Still, it may be years before the refuge can gain control over the carp. "There are some really tough issues to grapple with," said Sallinger, a working group member who suspects the battle against carp will guide refuge polices for 15 years.

Carp are native to Europe and Asia and were artificially introduced into the Silvies River in about 1920, probably to keep nearby irrigation canals open on the premise that carp would eat aquatic plants and algae, Beck said.

Their numbers in Malheur Lake -- which averages 18 inches deep -- verges on the unbelievable. Biologists estimate 1.5 million carp inhabit the lake, although nobody knows for sure. Collectively, they could weigh 7 million pounds.

More: http://www.oregonlive.com/news/index.ssf/2010/05/fish_invaders_are_eating_birds.html