Environment DEC
From the June 2009 issue
DEC Confirms Presence of Didymo in Esopus Creek
DEC recently announced that didymo, a destructive invasive species of aquatic algae, has been confirmed in the Esopus Creek in Ulster County. This is the first known presence of this algae, also called "rock snot," in the Esopus and the third confirmed location in New York State. The Esopus is a popular recreational waterway for fishing, kayaking and tubing, and is a drinking water source for New York City.
Didymo has been found in the Esopus below the Shandaken Tunnel in Ulster County.
DEC collected samples and confirmed the presence of didymo in the vicinity of several public access sites along a 12-mile stretch of the Esopus from the "Shandaken Portal" (which transfers water to the Esopus from Schoharie Reservoir) to New York City's Ashokan Reservoir.
Didymo's Impact
Unlike many other aquatic invasive plants, didymo (Didymosphenia geminata) grows on the bottom of both flowing and still waters. It is characterized by the development of thick, gooey mat-like growths, which can last for months, even in fastflowing streams. In addition to making footing difficult, didymo can impede fishing by limiting the abundance of bottom-dwelling organisms that trout and other fish species feed on. No methods for controlling or eradicating didymo once it infests a water body are currently known.
Spotting Didymo and Preventing its Spread
Didymo mats look like brown or white fiberglass insulation or tissue paper (see Common Aquatic Invasive Species). While didymo appears slimy and stringy, it feels rough and fibrous-similar to wet wool-and does not fall apart when handled. Previously, didymo had been confirmed in the Batten Kill in Washington County near the Vermont border and in the East and West branches of the Delaware River.
Didymo forms thick mats on stream bottoms and smothers bottom-dwelling organisms.
"The presence of didymo in another popular New York waterway highlights the crucial need for people to be diligent in preventing the spread of invasive species," Commissioner Grannis said. "Invasives can have a devastating impact not only on the environment but also the economy. I urge all outdoor enthusiasts to help out by adopting the 'Check, Clean and Dry' method for limiting the accidental transport of didymo and other invasive species from infected waterways to uninfected water bodies."
See DEC's Preventing the Introduction and Spread of Aquatic Invasive Species web page for information on stopping the spread of aquatic invasive species of all kinds, including didymo.
