The worst invasive species in the Great Lakes, Sea Lamprey, are showing significant declines across the region.
Since the parasitic fish first arrived in the Great Lakes in the 1920’s it has devastated the fishery.
At their height, before a suitable lampricide was discovered, the invasive fish was destroying 103 million pounds of fish every year. Now, that number is closer to 10 million pounds.
The Great Lakes Fishery Commission, which oversees control and research of lamprey, is reporting lamprey populations are either declining or holding steady across the Great Lakes.
Marc Gaden is with the Commission.
“Certainly the fish of the Great Lakes have good reason to be comforted by these numbers because there are fewer, far fewer of these lampreys out there after their blood,” he said.
Gaden said in Lakes Michigan and Ontario lamprey are at near historic lows. Lakes Superior and Erie were above targets but have seen significant declines since near record highs in 2017.
But, he said, there’s no way to completely eliminate the fish from the ecosystem.
“There’s no possibility of getting that last mating pair. If there was it was astronomically expensive, far more costly than the value of the fishery,” Gaden said.
Another commission member, Doug Stang, noted in a statement that the lamprey control program is “the most successful aquatic vertebrate pest control program at the ecosystem scale in the world.”