A plea to wipe away rock snot
Officials try to halt slimy-looking algae's slide into N.E.
It looks like brown slime and feels like wet wool, and it may be harming aquatic life in rivers and streams in northern New England.
Rock snot is in the region, and the single-cell organisms - which can live up to three months out of water in dark, cool damp places - are silently spreading.
Officials in Massachusetts and other New England states, worried that the goopy mats could scare off anglers and swimmers, are launching an intensive public outreach effort to find rock snot outbreaks and contain them.
"Rock snot certainly has that gross factor," said Amy P. Smagula, exotic species program coordinator for New Hampshire.
The algae were first discovered last year in a 43-mile length of the upper Connecticut River on the Vermont and New Hampshire border. Soon after, rock snot was seen in the White River in Vermont and then in the Batten Kill River, which flows from New York into Vermont and is renowned for its trout fishing. There have been no sightings yet in Massachusetts.
State environmental officials believe that people are inadvertently spreading the algae on boat hulls, fishing waders, and clothing. Vermont and New Hampshire have posted signs along waterways to warn boaters and fishermen to wash gear carefully.
Brochures and fact sheets are being printed to help fishermen and boaters identify the invasive algae. Some environmental workers in Massachusetts, New Hampshire, and Vermont have switched from felt-soled to rubber-soled waders, because they are easier to disinfect.
Officials are focusing on stopping the spread of the algae, because "we don't know how to get rid of it," Smagula said. Gear should be scrubbed with hot water or a bleach solution. If that isn't practical, people are urged to dry out gear or boat hulls and wait 48 hours before going in a new waterway.
Didymosphenia geminata, or didymo for short, is a freshwater diatom that attaches to rocks in streams or other bodies of water with stalks. The stalks accumulate and form a mass that can look like raw sewage on the rocks and trail 2 to 3 feet in the current. The algae eventually die and decompose, but the stalks persist for months on the river or stream bottom, and some research suggests it can choke out native vegetation and harm habitat for some aquatic life such as snails. It is not harmful to humans.
Scientists are puzzled by the invasion because, unlike zebra mussels or green crabs, rock snot may be native to North America and the Northeast, although spotty records suggest that if it was here, it was never in any great abundance. A 1988 book on freshwater and marine plants in Rhode Island identified the species, and historical records reported it in the Delaware River in the early part of the 20th century.
But starting about a decade ago, the species seemed to go haywire. It spread across freshwater bodies on Vancouver Island in Canada and began proliferating in Alberta and then Quebec. Four years ago, it appeared for the first time on New Zealand's South Island, where it is now considered a major ecological and tourism threat, because people don't like going in streams and rivers where it blooms. Officials are so worried about it there that anyone caught intentionally spreading it faces up to five years in prison and a fine of 100,000 New Zealand dollars, about $80,000 in US funds.
New England was considered safe until last year, when a fisherman found the algae on the Connecticut River. Rock snot was later found in isolated locations along 43 miles of the Connecticut, covering the river bottom from bank to bank in some places with the goopy-looking mats.
Scientists know little about rock snot. It was long thought that the species thrives in cold, clear, low-nutrient streams, but rock snot is now being found in warmer, turbid waterways with more nutrients. Scientists want to know whether the species has adapted to these different conditions.
"We have a lot to learn," said Sarah Spaulding, an ecologist with the US Geological Survey in Colorado who is studying the algae. There currently are no studies of the organism funded in the United States, but there needs to be, she said. "We need to be able to answer the crucial questions."
Environmental officials are asking the public to report any possible sightings of the algae, note the exact location and, if possible, collect a dime-sized sample in a plastic bag or folded in a business card and send it to state environmental officials.
"This can spread by a single cell or drop of water," said Adrienne Pappal, aquatic invasive species coordinator for Massachusetts.
Officials fear that it is only a matter of time before rock snot turns up in the state. "If everyone cleaned their gear, that is the best hope we have," Pappal said.
Beth Daley can be reached at bdaley@globe.com. 