These are the same eels that collapsed the fish populations in the Great Lakes in the space of just 9 years.
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
We're way beyond the point that the Great Lakes are going to have a naturally ocurring ecological balance resembling what it originally was. It's too late for that. In the past 100 years we've let in hudreds of invasive species, we've created locks and channels and joined the Great Lakes watershed with the Mississippi watershed.
There's no going back to what things were once.
All we can hope for now is to make it something that we like, and something that gives native species a good sporting change of surviving. As it happens, we have managed to achieve something resembling a balance through hard work and constant investment, and it yields a 7 billion dollar fishing industry.
Reducing funding for lamprey control is a huge mistake, and will cost the region and the nation far more than the cuts save.