Anyone smelling death would probably crinkle up their nose and say "Ew." But nothing compares to the adverse reaction these sea lampreys have when the repellant odor is poured into their tank.
This experiment wasn't just done for the gross factor of sea lampreys spewing out of the water. Sea lampreys are one of the most destructive invasive species in the Great Lakes. Researchers that Michigan State University are looking into the use of such repellants to prevent the ever growing sea lamprey population from entering certain areas.
New Scientist has more:
“Sea lampreys are one of the most costly and destructive Great Lakes’ invaders,” said Wagner, who published his results in the current issue of the Canadian Journal of Fisheries and Aquatic Sciences. “The effectiveness of the odor combined with the ease in which it’s obtained suggests that it will prove quite useful in controlling sea lampreys in the Great Lakes.”
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“It’s kind of like a stop light, a noxious odor that causes them to run away from its source,” he said. “By blocking certain streams with these chemical dams, sea lampreys can be steered away from environmentally sensitive areas and into waterways where pesticides could be used more effectively to eliminate a larger, more concentrated population of sea lampreys.”
This approach would allow agencies that control invasive species to save money, use less pesticide and manage other resources more efficiently to have a bigger impact on controlling the invasive species, Wagner added.
Currently, pheromones are used to lure sea lampreys into traps, where they are then killed or sterilized. The researchers said that pheromones are not always as effective in waterways with many other chemical signals, but hope repellants will do the trick.