The U.S. and Canadian governments have cooperated since the 1950s on reducing the population of lampreys, eel-like creatures that slithered into the lakes from the Atlantic Ocean through shipping canals. A combination of trapping, sterilization and application of poisons in streams where they spawn has dropped their numbers by about 90 percent, enabling fish such as lake trout to begin recovering.
But funding reductions over the next two years proposed by members of Congress and the Obama administration could force the Great Lakes Fishery Commission, the binational agency that runs the lamprey control program, to scale back operations in crucial locations, spokesman Marc Gaden said.
“Even a short-term relaxation of lamprey control sets us back a decade or more in fishery restoration,” Gaden said. “You’re talking about the potential for significant numbers of lampreys to survive and go out into the lakes to kill fish.”
Lampreys use their round, disklike mouths filled with sharp teeth to attach themselves to fish and suck their blood, weakening and often killing the hosts. With no natural predators in the Great Lakes and a wealth of tributary waters providing ideal spawning grounds, it’s considered impossible to eliminate them. Scientists continue developing new methods of keeping them in check, such as using pheromones — sex scents emitted by male lampreys — to lure females into traps.
Controlling lampreys is labor-intensive. Crews head into the field each spring to set traps and look for streams where lampreys have laid eggs, enabling the commission to decide which should be treated with a liquid chemical that kill lamprey larvae but are believed to spare other fish.
About 480 tributaries have been treated since the program began, with 167 hot spots getting doses of the chemical every few years. In the typical year, about 100 are treated.
A granular biocide is used in the St. Marys River, which forms a 60-mile-long link between Lakes Superior and Huron and is the biggest lamprey spawning area. Its size and swift currents make the liquid ineffective.
The U.S. share of the Great Lakes Fishery Commission budget, 90 percent of which goes to lamprey control, was $21.7 million in 2010. Its fate in the current fiscal year depends on whether it takes a hit as Congress works out details of an agreement reached Friday to cut $38 billion in federal spending.
A package of cuts approved earlier by the House and rejected by the Senate would slash the commission’s budget by 20 percent in 2011. Supporters in the Senate hope to keep the funding at last year’s level, “which would allow us to deliver pretty much a complete program,” Gaden said.
After 2011 spending is determined, Congress will begin work on the 2012 budget submitted by Obama, which would allocate $18.7 million for the commission — about 15 percent less than last year.
Such cuts would require the commission to choose between across-the-board reductions in stream treatment or continuing full treatment in some areas while doing nothing in others. Either option would boost lamprey numbers, Gaden said. They are prolific, with each spawning female capable of laying up to 100,000 eggs.
His agency has calculated that a 20 percent funding cut would allow the population to rise from the estimated 320,000 at present to about 550,000, causing a loss of about 9 million additional pounds of fish. Many victims would die before they are mature enough to reproduce, further hampering efforts to restore trout, salmon and other species.
Sen. Carl Levin, a Michigan Democrat and co-chairman of the Senate’s Great Lakes Task Force, told The Associated Press last week he would “fight hard against any reductions in funding” for lamprey control.
John Atwell, a Lake Huron charter boat captain based in Port Austin, said a lamprey population explosion could ruin his business, already badly damaged by the collapse of the lake’s salmon fishery in the past decade because of overpopulation and loss of prey fish. The likely culprit is the invasive quagga mussel, which vacuumed up plankton that formed a vital link in the food chain.
About three dozen charter boats operated in his area seven years ago, Atwell said. Perhaps 10 are left.
“With the salmon being gone, the charter captains are looking for lake trout and steelhead and walleye,” he said. “If they let the sea lamprey get out of control again it will decimate probably 50 percent of the fish ... one more crushing blow.”
— By John Flesher/Associated Press