Now jellyfish are on the move

ecological balance. We’re not seeing rapid spread or rapid numbers.”

Native to China’s Yangtze River, it is believed the invertebrates were transported to the United States with ornamental aquatic plants and fish stocks. U.S. Fish and Wildlife Service reports it was first documented outside of China in water lily tanks at London’s Regents Park in 1880. Today the jellyfish is commonly found throughout Europe, Asia, North and South America and Australia. Its spread around the globe is linked to the stocking of fish, like tilapia, the movement of aquatic plants, like water hyacinth, and the migration of birds, all of which can inadvertently carry the polyp and podocyst forms of the animal.

In the U.S., freshwater jellyfish were discovered in the Huron River near Ann Arbor, Mich., in 1933, according to the U.S. Geological Survey. They have since been recorded in lakes Huron, Ontario, St. Clair and Erie, and in dozens of inland lakes and streams in Illinois, Indiana, Michigan, Wisconsin, Minnesota, New York and Ohio.

Freshwater jellyfish in Canada have been recorded in Quebec since 1955 and in portions of Ontario since 1980, according to the U.S. Geological Survey.

Even though the tiny invertebrates do not appear to pose a threat to people, Stahlman urges the public to report jellyfish sightings to authorities.

“It’s very important to be diligent, and if you see something that doesn’t look right, report it, she said.