A repellant for sea lampreys could be the key to better controlling
one of the most destructive invasive species in the Great Lakes,
says a Michigan State University researcher.
Scientists have seen the effect alarm cues have on lampreys. When
scents from dead sea lampreys are poured into a tank of live ones,
the lampreys' efforts to escape are dramatic. In the past, these
reactions were simply dismissed as novel. But Michael Wagner, MSU
assistant professor of fisheries and wildlife, sees this reaction
as a potential game changer.
"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."
Discovering an effective repellant puts research to control sea
lampreys on a new path.
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
said.
"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.
"Thanks to this exciting new research on alarm substances, we
believe we are on track to bring sea lamprey control to a whole new
level," said Robert Lambe, chairperson of the Great Lakes Fishery
Commission.
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Thanks to Michigan State University for this article.