Demystifying Science’s ‘Forbidden Experiment’: Why Scientists Kill 9 Million Lampreys Every Year in America’s Great Lakes
Six sea lampreys pose for the camera at the Capitol during a meet-and-greet organized by GLFC in June. One even sucked on Rep. Bill Huizenga’s palm, according to CNN. One of the few things the entire Congress agreed on was this: the invasive sea lampreys must be eradicated.For U.S. coasts that thrive on seafood, the invasive species, also known as “vampire” fish or the “vampires” of the Great Lakes, has had a devastating impact on the lakes’ trout, salmon and whitefish populations. Thus, inspiring what scientists often call “forbidden experiments.”
Arrival of sea lampreys
loss of native fish
forbidden experiment
In 1954, Canada and the United States formed a partnership to address the lamprey problem, and the Great Lakes Fisheries Commission (GLFC) came into being. A moonshot attempt at population control succeeded in 1957, when a compound called TFM (3-trifluoromethyl-4-nitrophenol) was developed that killed lamprey larvae but left most native fish unharmed. Since then, “lamprey killers” have been used in the spawning areas of the lake’s tributaries from spring to autumn to kill juvenile lampreys before they enter the lake, which is beyond the capabilities of scientists.Dampicides are effective because the larvae are unable to metabolize the compound, disrupting their energy production and causing death. Nearly 70 years after its introduction, there is no sign that lampreys have developed any resistance to it.Nearly seventy years after the moon landing, all efforts were nearly in vain. During the 2020 and 2021 lockdowns, staff had to maintain social distancing, which resulted in fewer treatments and the council was unable to implement a comprehensive control plan. Greg McClinchley, director of policy and legislative affairs for the Great Lakes Fisheries Commission (GLFC), said lamprey populations have “jumped” by 300 percent in some areas. “It really proves (our) case.”“We call it ‘no experimenting’ in the office,” he added. “We always said that if we didn’t continue to control sea lampreys, they would come back – they were a coiled menace. But we never dared to do that.”To prevent population explosion, approximately 9 million lampreys need to be killed each year. If left unchecked, the GLFC said it estimates lampreys could devastate fish stocks in the Great Lakes in just five years, taking with them a multi-billion-dollar fishery.
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Other species, such as quagga mussels and zebra mussels, are also now plaguing the lake.
Sea lampreys are just one of 186 of 3,000 invasive species in the Great Lakes. Other species, such as quagga mussels and zebra mussels, are also now plaguing the lake. The mussels arrived in the ballast water of commercial ships in the 1980s and have affected fish eggs ever since, causing toxic algae blooms and outcompeting native mussels. Invasive mussels are also suspected of being a factor in an increase in avian botulism deaths in recent decades. They concentrate Clostridium botulinum, while another invasive species, the round goby, feeds on the mussels. Scientists speculate that poisoned gobies become paralyzed and become easy prey for birds, which then succumb to the toxin. There is currently no way to safely eliminate them from the Great Lakes.“They strip the water of nutrients and plankton, disrupting the food web that whitefish and other species depend on. In Lake Huron, the decline in whitefish numbers has almost paralleled the rise in mussel biomass,” said Vito Figliomeni, executive director of the Ontario Commercial Fisheries Association.According to CNN, legislation has been introduced in Congress that would require the commission to find controls. The bipartisan bill, known as the Save the Great Lakes Fish Act of 2025, proposes a $500 million budget over 10 years to find solutions.
