Hydrilla closes in on the Great Lakes

The first collection of Hydrilla verticillata from
Tonawanda Creek. Credit: USFWS

You don’t necessarily need to be looking for an aquatic invasive species to find it. Sometimes it appears when you least expect it.

That’s exactly what happened in early September, when Lower Great Lakes Fish and Wildlife Conservation Office staff discovered Hydrilla verticillata, a highly invasive aquatic plant, in the New York State Canal System in Tonawanda, N.Y. The location was literally at the base of a boat ramp, a highly visible area that should lend itself to early discovery.

Nonetheless, it apparently went unnoticed for some time, hiding within the abundant native plants, particularly Canadian/common waterweed, a native aquatic plant similar in appearance. The distinction between the two is important, as hydrilla crowds out waterweeds and other essential plants. It slows water flow and can clog lakes and rivers enough to even eliminate swimming or boating.