WATERBURY, Vt. – A species of invasive algae with an unusual nickname has been found in the northern stretches of the Connecticut River, the first time it ever has been spotted in the Northeast. Didymosphenia geminata, sometimes referred to as “rock snot,” has been seen growing on rocks near Bloomfield, which concerns state biologists.

The algae can smother aquatic plants and destroy fish habitats.

On June 25, a fishing guide spotted it on rocks in the river near Bloomfield and reported it.

Dr. Sarah Spaulding of the U.S. Geological Survey, an expert about it, confirmed that the plants are indeed didymo, which has no known control. The only defense against it is preventing the spread, said Angela Shambaugh, an algae expert at the Department of Environmental Conservation.

Outdoor sports enthusiasts – fishermen, kayakers, canoeists, boaters – can spread didymo accidentally when its microscopic algae cling to fishing gear, waders, boots and boats.