Michigan State University has several laboratories dedicated to the study and control of lampreys, which are special disciplines. Lamprey skeletons are made of cartilage rather than bone, and they can regenerate a fully functional spinal cord even when they are cut in half. According to Michigan State University professor Anne Scott, they have incredible olfactory abilities, capable of detecting odors in extremely low concentrations — the equivalent of finding a few grains of salt in an Olympic-sized swimming pool. Aboriginal people lived in brackish water and then swam to inland tributaries like parasitic salmon to breed and die. Lamprey species have lived on Earth for hundreds of millions of years; they predate dinosaurs and have survived at least four mass extinctions.
These unique adaptations have earned sea lampreys the grudging admiration of the conservationists tasked with eradicating them. “There’s no denying that invasive species can wreak havoc on the environment,” Griffin said. “But you have to respect an animal that has held on for so long.”
sometimes in 19th century, Petromyzon Marinus It first winds from the North Atlantic into Lake Ontario. On its southeastern edge, the 3,100-foot span of Niagara Falls provides a natural barrier against further westward expansion of the species, but the deepening of the man-made Welland Canal provides an alternative pathway. Once in the larger Great Lakes, sea lampreys encounter a buffet of trout, sturgeon, whitefish, walleye, catfish and other native aquatic species. Lampreys continue to bite, burrow and suck out the blood and bodily fluids of millions of fish – causing massive fish casualties. Few, if any, predators stop their spread.
As the problem worsened, humans began to feel their presence. By the mid-1940s, in northern Lakes Huron and Michigan, about four-fifths of commercially caught fish were so wounded by lampreys that they could not be sold. In the Lake Michigan portion of Michigan alone, 6.5 million pounds of lake trout were caught in 1944, but less than five years later, only 11,000 pounds were caught for the entire lake. Battered by lampreys, overfishing and pollution, regional fisheries were losing tens of millions of dollars a year by the 1960s. In 1949, commercial fishermen testified to Congress that their industry was “doomed.” Fishermen and residents alike cringe at the blood-sucking parasite. “People thought they were like horrible creatures from the bottom of the earth,” said a woman whose family owns a fishing resort near Duluth Great Lakes Sea Lampreys: The 70-Year War Against Biological Invaders.
In the early days of the invasion, wildlife managers and local residents fought sea lampreys with everything they could think of. From dip nets to spears, few weapons go untested. Conservationists have built rudimentary metal barriers to keep migrating adults from reaching their spawning grounds, and have used newly invented electric fishing equipment to kill the larvae. At one dam, operators built a booby trap with metal ramps to guide lampreys over the edge of the dam and into a barrel of oil. A conservation officer named Marvin Norton led a pitchfork-wielding sports club on excursions to hunt lampreys. Every effort has failed. “I suspect lampreys will be with us from now on like fleas on dogs,” Gerald Cooper of the Michigan Department of Conservation said in 1954.
At the current U.S. Geological Survey’s Hammond Bay Biological Station, scientists diligently search for chemical solutions. In 1956, they finally got lucky with the 5,209th formula they tested: 3-trifluoromethyl-4-nitrophenol, or TFM. The researchers were excited that TFM could eliminate lamprey larvae while preserving most of the protist biota. Two years later, the new lampkiller was injected into Michigan’s Mosquito River.
In 20 years, TFM proved to be a powerful weapon. It is especially effective when combined with the region’s abundance of dams, which block more than half of the sea lamprey’s potential spawning habitat. By 1978, the number of sea lampreys spawning in Lake Superior had dropped by 92 percent. Across the Great Lakes, lamprey populations have fallen from a peak of 2 million in the 1950s to hundreds of thousands today.
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