This story was originally Appears on Yale environment 360 and is part of Climate table cooperation.
“Thousands of lampreys swim upstream [on the Connecticut River] each year. This is the predator that wiped out the Great Lakes trout fishery. [Lampreys] literally sucking life out of their hosts, specifically small-scale fish like trout and trout. Fish ladders should be used to shrink lampreys.” So editor Eagle-Tribune by Lawrence, Massachusetts, on December 15, 2002.
If that’s true, why this spring Trout Unlimited—the nation’s leading salmon and trout advocate—supported the Town of Wilton, Connecticut, and an environmental group called Save the Sound in a project Will the project restore 10 miles of sea lamprey breeding habitat on the Norwalk River that flows into Long Island Sound?
Why this summer will be the first big profit from stocked Pacific lampreys—a species similar to sea lampreys—climbing specially designed lamprey ramps at dams on the Columbia River and spilling into historic breeding habitats in Oregon, Washington, and Idaho?
And why, when the canal at Turners Falls on the Connecticut River is drained in September, the Connecticut Rivers Conservancy, Fort River Watershed and Biocitizen Environment will rescue stranded sea lamprey larvae?
The answer is ecological awakening—the gradual realization that, if all of nature is good, no part is bad. In their natural habitat, sea lampreys are the “key species” that support extensive terrestrial and aquatic ecosystems. They provide food for insects, crayfish, fish, turtles, weasels, otters, vultures, herons, loons, ospreys, eagles, and hundreds of other predators and scavengers. Lamprey larvae, located in stream beds, maintain water quality by filtering food; and they attract breeding adults from the sea by releasing pheromones. Because the adults die after spawning, they transfer nutrients from the sea into sterile watersheds. As lampreys build their nests, they clear silt from the riverbed, providing a spawning environment for a multitude of native fish, especially trout and trout.
Environmental consultant Stephen Gephard, formerly head of Connecticut’s anadromous fish group, calls lampreys “environmental engineers” just as important to native ecosystems as beavers.
Sea lampreys, which are about 340 million years older than us, depend on cold, free-flowing freshwater to reproduce. They are boneless, jawless, eel-like fish with fleshy fins. They suck the body fluids of other fishes through toothed suckers. Both the sea lamprey and the Pacific lamprey are widely denigrated because they are considered “ugly” and because the lampreys slaughtered native fish species upstream of the Great Lakes as they approached the Great Lakes. access to that body of water through man-made canals, most likely the Welland Canal bypassing Niagara Falls. Once there, they nearly wiped out the valuable commercial and sport fisheries of lake trout (the largest, non-true trout such as rainbow trout, cutthroat trout, and trout. brown).
By the 1960s, non-native sea lampreys had reduced the annual commercial production of lake trout upstream of the Great Lakes from about 15 million pounds to half a million pounds. In 1955, Canada and the United States established the Great Lakes Fisheries Commission, which controls lampreys with barriers, traps, and a specially selected larval poison called TFM. Lampfish control costs $15 to $20 million a year; and without it, the ongoing lake trout restoration would not be possible and the populations of all other sportfish would be in decline.
