No wonder feds take risks to kill lampreys – stakes are high

Sea lampreys have had an enormous, negative impact on the Great Lakes fishery.

Editing a story about the recent fishkill on Conneaut Creek resulting from a botched application of lampricide by the U.S. Fish and Wildlife Service, I realized that I didn’t know much about the history of the sea lamprey in the Great Lakes.

I was aware that the feds still dump poison into tributaries to control the parasite, but I hadn’t considered the justification.

However, after boning up on the lamprey’s history in the Great Lakes, I understand. It turns out sea lampreys are the mother of all invasive species that have inflicted an unbelievable amount of damage on the fishery. You may be interested in what I learned,

First, in their native Atlantic Ocean, thanks to co-evolution with fish there, sea lampreys are parasites that typically do not kill their host. But in the Great Lakes, sea lampreys act as predators, with each individual capable of killing up to 40 pounds of fish over their 12-18-month juvenile feeding period.

Sea lampreys have had an enormous, negative impact on the Great Lakes fishery. According to the Great Lakes Fishery Commission, before the sea lamprey invasion, Canada and the United States harvested about 15 million pounds of lake trout in the upper Great Lakes each year. By the late 1940s, sea lamprey populations had exploded.

They fed on large numbers of lake trout, lake whitefish and ciscoes — fish that were the mainstays of the Great Lakes fishery. By the 1960s, the catch had dropped dramatically, to about 300,000 pounds — just 2 percent of the previous average.

And during the time of highest sea lamprey abundance, the commission estimates, 85 percent of fish not killed by sea lampreys were marked with gruesome sea lamprey attack wounds.

Successful sea lamprey control has allowed for the rehabilitation of a healthy Great Lakes ecosystem and economy now valued at more than $7 billion annually. These strides have only been made possible through the annual application of the sea lamprey control program – putting lampricide in tributaries. It has reduced sea lamprey populations in the Great Lakes by more than 90 percent from their pre-control abundance.

So, you see why the feds risk fishkills like the one that recently occurred in Conneaut Creek. The stakes are high.

Categories: Blog Content, Pennsylvania – Jeff Mulhollem

Leave a Reply

Your email address will not be published. Required fields are marked *