Detroit River could become hotbed of sea lamprey activity

In their search to figure out what is causing an increase of sea lampreys in Lake Erie, scientists are studying connecting rivers, streams and bodies of water. While the Detroit River was deemed not to be causing the issue, it has been flagged as an area of future concern.

Scientists trying to figure out what is causing increase of the species in Lake Erie

Sea lamprey numbers are on the rise in Lake Erie. (Fort Folly Habitat Recovery)

The Detroit River has the ingredients necessary to become a breeding ground for sea lampreys.

That's the finding of a recent study of the river by the Great Lakes Fishery Commission (GLFC), a joint Canada-United States organization that has been fighting the toothy, eel-like invasive species for decades.

While sea lamprey reduction efforts have been widely considered a success, a recent increase in the number found in Lake Erie has officials concerned.

"They're about three or four times higher than they should be," said Marc Gaden, communications director and legislative liaison for the GLFC. "We're doing well in our other lakes, but Lake Erie is kind of ground zero for lamprey abundance."

Streams connected to Lake Erie have been treated with lampricide, but Gaden said numbers in the lake are still too high. As a result, scientists have been studying connecting rivers and bodies of water in the hopes of finding where the lampreys come from.

While studying the Detroit River, crews determined that the river is a suitable habitat for lamprey, and that a small number are present — but mainly of the less destructive native variety.

"We ... think that because of the small number that they found, [the Detroit River] is a future threat as opposed to what's causing the problem in Lake Erie right now," Gaden said.

The GLFC believes that Lake St. Clair, specifically, the area near Walpole Island, contains the habitat producing the lamprey that eventually make it down to Lake Erie.

A collaboration with the Walpole Island First Nation has been established to pinpoint the exact breeding ground.


Jonathan Pinto is the host of Up North, CBC Radio One's regional afternoon show for Northern Ontario and is based in Sudbury. He was formerly a reporter/editor and an associate producer at CBC Windsor. Email


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.

Become a CBC Member

Join the conversation  Create account

Already have an account?