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.

Freshwater mussel conservation in western New York

This post is part of a series running all month on freshwater mussels, highlighting their importance to the Northeast landscape and the concerted efforts underway to ensure their future in our waters.

Nestled between Lake Ontario and Lake Erie in western New York, the Service's Lower Great Lakes Fish and Wildlife Conservation Office is located in an incredibly unique area. Part of the reason this area is so interesting is the high number of streams with freshwater mussels.

A native freshwater mussel found in the stream during a road-crossing survey. Credit: USFWS

Freshwater mussel populations are in decline all over the country. Pollution and habitat loss are two of the leading causes of the population decline. As the human population grows and cities spread out, more roads are built, many of which cross streams. When those road crossings are installed correctly, they cause no problems.

However, due to budget constraints and lack of training for the installers, many crossings are under-sized or incorrectly installed. This causes a major problem for fish and other critters that live in the stream. The road crossing becomes a barrier to fish migration, as well as the migration of other species, including freshwater mussels.