From the Boulder Daily Camera (Laura Snider):

“Diatoms pretty much grow everywhere, whether it’s really clean water or waters that are relatively impacted,” said Sarah Spaulding, a researcher at the University of Colorado’s Institute of Arctic and Alpine Research. “Generally, the more nutrients you get in the water, the more biomass you get. “What’s different about this diatom is that we found it would make a large amount of biomass where there weren’t many nutrients in the water.”

This has allowed rock snot, an invasive species in North America, to explode in streams that have not historically supported large algae blooms. In a study published in the journal Geophysical Research Letters, the scientists explain how Didymo does it. The key is Didymo’s stalks, which keep the algae attached to the rocks. The stalks are able to collect the limited phosphorous nutrients available in the stream on their surfaces along with iron. Then, bacteria that live in the rock snot mats interact with the accumulated iron to make the phosphorous easier for the algae to use.