Posts Tagged ‘rock snot’

National Invasive Species Awareness Week – Didymo (Rock Snot)

Posted on: March 1st, 2018 by Leslie_Zucker

Day 4 of National Invasive Species Awareness Week is dedicated to Rock Snot!

What is it?

Didymosphernia geminata a.k.a. Didymo a.k.a. Rock Snot, is an aquatic, invasive, microscopic diatomaceous algae that produces high volumes of stalk material, which is why you may see thick mats on stream bottoms. It is often brown, tan, or white, with the appearance and texture of wet wool that does not fall apart easily.

Didymo in the Esopus Creek. photo courtesy of NYIS

Didymo in the Esopus Creek.
photo courtesy of NYIS

How does this impact streams?

Because Didymo grows on the bottom of streams and still waters, and forms thick mats of material, it can last for months, despite occurring throughout some fast moving streams. When Didymo grows, or blooms, it covers entire stream beds, covering over native organisms, and restricting the availability of food for native fish species. It spreads quickly and easily due to water recreation activities. Fishing, kayaking/canoeing, tubing, and boating allows the microscopic algea to attach onto your boots, waders, and boats, and if not cleaned off properly, it will spread to the next body of water you go to. Currently, there are no control methods available to stop the spread and eradicate Didymo.

Make it stop!

NYS DEC urges the public to use the “Inspect, Clean and Dry” method to decrease the spread of invasive species. If for any reason you can’t get your equipment clean and dry, restrict your equipment to a single water body.

Density Observations of Rock Snot. map courtesy of NYIS

Density Observations of Rock Snot.
map courtesy of NYIS


**Attention Felt-Sole Waders! We encourage you to consider other alternatives, such as rubber studded boots. Because felt-soles absorb Didymo cells and remain absorbent for long periods of time, the spread of Didymo can increase rapidly if special treatments are not conducted.

Check back tomorrow for our final day of National Invasive Species Awareness Week!

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