Rock Snot
 

TCT,

Although this topic is hotter in the fishing community, it affects all folks who enjoy our lakes and streams. Note that Maryland has just banned the use of felt-soled waders in its waters in an effort to keep Didymo out of its waters that are not already infected with it.

http://www.dnr.maryland.gov/dnrnews/...011/031711.asp

http://en.wikipedia.org/wiki/Didymosphenia_geminata