Lake Erie is being invaded by jellyfish. But is it a problem?

Photo by Michael Wende/shutterstock

By Jessica Faulds

Ontarians are used to hearing tales of invasive zebra mussels and Asian carp in the Great Lakes, but lately, a new species has been making headlines for its unexpected presence. Freshwater jellyfish have been spotted in Lake Erie (and other lakes) recently, and they’re generally believed to be invasive.

Posted by Darien Donnelly on Saturday, July 8, 2017

The jellyfish aren’t actually new — they were spotted in the Great Lakes as early as the 1950s, and were probably there long before that. However, new sightings have brought the jellyfish into the spotlight, and the scientific community’s reaction to them has been mixed. There’s one thing most people agree on, though: they will likely be impossible to get rid of.

“There’s no known way to remove freshwater jellyfish from a lake ecosystem once it is there,” Jeff Brinsmead, an invasive species biologist with the Ministry of Natural Resources and Forestry, told the National Post.

It’s thought that the jellyfish originated in Europe and were brought to Canada on aquatic plants in the 1800s. However, some scientists think the jellyfish may have always been here — and even if they weren’t, they may not be harmful.

Ted Peard, a biologist who studies the jellyfish and runs a website where people can report sightings, told the Toronto Star that the question of whether the jellyfish are invasive or not is “debatable.”

“I haven’t been given a definitive answer by any agency, anybody I’ve talked to, that leads me to believe that they couldn’t have always been here,” he said. “I just don’t know.”

The Ministry of Natural Resources and Forestry has also said the jellyfish are unlikely to harm the ecosystem. They may compete with fish for food, but they can also be eaten by turtles and crayfish, and they do not sting people.

Map of jellyfish sightings
A map showing the distribution of reported freshwater jellyfish sightings. [Credit: eddmaps.org]

Though the jellyfish have been around for years, their appearance still catches people by surprise. A recent video posted by Darien Donnelly showing a jellyfish she and her boyfriend had caught recently went viral. They caught the jellyfish at a bridge in Port Dover, Ontario.

The Ministry of Natural Resources and Forestry has encouraged lake users to report jellyfish sightings, and to take photos if possible.