The New York State Department of Environmental Conservation (DEC) has confirmed that didymo is present in a section of the Batten Kill in Washington County. It is the first known presence of this aquatic nuisance algae--also called "rock snot"--in New York State.Read the entire article, including tips for prevention and control at http://www.dec.ny.gov/environmentdec/36890.html
Unlike many other aquatic nuisance plants, Didymosphenia geminata grows on the bottom of flowing and still waters. It can develop thick mats even in fast-flowing trout streams. In its presence, fishing becomes difficult, the abundance of bottom-dwelling organisms declines, and trout and other fish that feed on those organisms also decline.
Meandering for 29 miles from Vermont to the Hudson River, the Batten Kill is a celebrated trout stream, as well as a popular watercourse for kayaking, canoeing and tubing. Didymo, which resembles rotting cardboard when exposed and dried, was observed in a section around and downstream of Route 22 where it crosses near the Village of Salem. Vermont also has confirmed the presence of didymo in a section just upstream of the border with New York State.
The microscopic algae cling unseen to waders, boots, boats, lures, hooks, sinkers, fishing line, and other fishing gear, and remain viable for several weeks under even slightly moist conditions. Absorbent items--for example, the felt-soled waders and wading boots commonly used by stream anglers--require thorough attention as discussed below. Anglers, kayakers and canoeists, boaters and jet skiers can unknowingly spread didymo.
Source: Environment DEC, NYS DEC's online newsletter