Dead smell freaks out pool of lampreys

MICHIGAN STATE (US) — The scent of their deceased brethren sends sea lampreys into a self-preservation tizzy as their alarm cues go into overdrive in an attempt to escape.

The findings could be a game changer in controlling one of the most destructive invasive species in the Great Lakes.

“Sea lampreys are one of the most costly and destructive Great Lakes’ invaders,” says Michael Wagner, assistant professor of fisheries and wildlife at Michigan State University.




“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.”

The research is published in the Canadian Journal of Fisheries and Aquatic Sciences.

Scientists had proven that the destructive species rely on the odor emitted by past generations of larvae to navigate into streams with suitable spawning grounds. Upon arrival, another odor emitted by mature males lures females onto nests to complete spawning.

Based on these observations, existing research has fully focused on using pheromones to attract sea lampreys into traps. Once caged, they are destroyed or sterilized and released back into the wild so they can be tracked but cannot reproduce.

But with many scent and environmental cues in natural waterways, using pheromones to attract sea lampreys doesn’t always work. On the other hand, repellants—even in miniscule amounts—may prove to be much more effective in diverting and corralling them, Wagner says.

“It’s kind of like a stop light, a noxious odor that causes them to run away from its source,” he says. “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.”

The 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.

The research was funded by Michigan State’s AgBioResearch and the Great Lakes Fishery Commission.

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