Rock Snot Algae Found in the Northeast

A type of invasive algae with the graphic nickname of "rock snot" has been found in the Connecticut River in Vermont, alarming officials and fishermen in New England and the Mid-Atlantic.

The VT Agency of Natural Resources confirmed that Didymosphenia geminata, or "didymo," has invaded the northern reaches of the Connecticut River. It's the first official report of the invasive algae in the Northeast. In other rivers invaded by didymo, there have been reports of massive blooms forming thick mats of cottony material on stream and river bottoms. The mats can smother aquatic plants and destroy fish habitat. Didymo is believed to be native to the far northern regions of Europe and Asia, although it has recently begun adapting to warmer waters. It is expanding its range in the western part of the United States and has infested rivers in several southeastern states, including Virginia, West Virginia, Tennessee and North Carolina.

Currently, no way is known to control or eradicate didymo once it infests a river or stream. The only defense is preventing its spread. Anglers, kayakers and canoeists, boaters and jet skiers can all unknowingly spread didymo. The microscopic algae cling to fishing gear, waders, boots and boats, and can survive for weeks in even slightly moist conditions. Even if didymo isn't visible, it can cling to clothes and equipment. 

The agency is urging people using Vermont's waters to:

  • Check: Before leaving a river or stream, remove all visible clumps of algae and look for hidden clumps. Leave them at the site. If you find any later, don't wash them down drains. Put all material in the trash.

  • Clean: Soak and scrub all items for at least one minute in either hot (140 degrees F) water, a 2 percent bleach solution or a 5 percent solution of salt, antiseptic hand cleaner or dishwashing detergent.

  • Dry: If cleaning is not practical, after the item is completely dry to the touch, wait an additional 48 hours before letting it contact any other waterway.

Barre-Montpelier Times Argus, July 8, 2007 http://www.timesargus.com/apps/pbcs.dll/article?AID=/20070708/NEWS02/707080426