It's ooey. It's gooey. It's heading for a rock near you.
IT'S ROCK SNOT!
You don't believe me? Check out this photo from the West Virginia Department of Natural Resources:
Scientifically know as Didymosphenia geminata and often called "didymo," this diatom, which is a kind of single-celled algae, can form large mats on the bottom of lakes, streams, and rivers. It's not dangerous to humans, but can kill fish and threaten rivers and streams by smothering native algae and and aquatic insects.
It's easy to transport and can multiply rapidly. In fact, it can multiple in a single drop of water. Apparently, it's on the march again, clinging to the bottoms of felt-soled fishing boots. Maryland has banned such boots, and other states plan to follow in short order.
Here are a few more randoms about this little menace:
1. Didymo are unique for their silica (SiO2) cell walls.
2. They live primarily in cool temperate regions of the Northern Hemisphere.
3. If you knowingly transport didymo in New Zealand, you could face up to 5 years in prison.
So, get out your gigantic hankies, and avoid that goo on the rocks.