Rock snot (Didymosphenia geminata) is an aquatic invasive alga common in hundreds of North American rivers and streams. Rock snot grows dense mats that cover the bottom of the stream floor and hinders water activities like boating and fishing. The potential habitat distribution in the US for rock snot is the subject of Sunil Kumar and colleagues’ research study, which is funded by EPA Region 8, the Natural Resource Ecology Laboratory at Colorado State University, and the USGS Fort Collins Science Center. Kumar et al. used prediction models (GARP, CART and the Maxent) to determine the areas in the US most likely to successfully support rock snot. Environmental variables characterizing climate, topography, bedrock geology and hydrology were considered in the Maxent model, which proved to be the most successful in predicting host sites for rock snot. Researchers learned that environmental conditions like elevation and temperature varied greatly where rock snot was discovered. Additionally, Kumar et al. noted that the potential control of a stream’s water flow could be the foundation for a rock snot management method.

Frontiers in Ecology and the Environment 7: 415-420 (2009).