Thursday, August 11, 2011

How to Terrify a Lamprey Eel: Applying Breakthrough Lamprey Control Methods this...this is what happens when sea lamprey smell the scent of a dead lamprey:

They have a dramatic flight response. They just want to get the hell out of there. This is one of the theoretical breakthrough lamprey control methods that scientists have been exploring.

Scientists believe this discovery can help them herd lamprey to specific areas where they can then whack them with lampricide. And by "whack" I mean, of course, "kill". It would require a lot less lampricide than if you're hitting an entire river, and would do a much more thorough job of eliminating a breeding population from a body of water.

Put simply when sea lampreys smell the scent of their dead brethren, they panic and flee. (To see the reaction, go here.)

That response could be used to help redirect the critters into a contained area where they could be killed with pesticide, said Michael Wagner, a marine biologist and professor at the Michigan State University’s department of Fisheries and Wildlife.

“If we can control their behaviour, we can pick the stream where they reproduce and protect other species in the rivers,” said Wagner, who also works for PERM, the Partnership for Ecosystem Research and Management, a joint program between Michigan State University and the Great Lakes Fishery Commission.

Sea Lamprey are an invasive species to the Great Lakes that nearly wiped out Great Lakes fish in the 1940s through 1960s. It was only after a massive effort and expense that we figured out how to control the animals and developed a toxin that specifically affects the Sea Lamprey. Control continues on an annual basis at an expense of 20 million dollars per year. Unfortunately, as it stands now we can't kill all the lamprey, we can just keep the breeding populations down. If we let up on the annual attempts to control the species, it would rapidly take over again. New methods of control are constantly being studied to reduce the cost and increase the effectiveness of lamprey control.

It bears repeating:

Sea lampreys feasted on lake trout...

Lake trout were the staple of the great Lakes commercial fishery before sea lamprey invaded. Anglers harvested some 15 million pounds of lake trout each year in Lakes Michigan, Huron, and Superior. By the early 1960s, the lake trout catch dropped to 300,000 pounds. The lake trout harvest in Lake Huron dropped from 3.5 million pounds in 1935 to 1000 pounds in 1949. The catch in Lake Michigan dropped from 5.5 million pounds in 1946 to 402 pounds in 1953. In Lake Superior, the catch dropped from an average of 4.5 million pounds annually to 368,000 pounds in 1961. An unsightly fish with no commercial value was making quick work of the most valuable sector of the Great Lakes commercial fishery, lake trout.

-- Jeff Alexander, Pandora's Locks

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