Life in Biofilm (image) Cary Institute of Ecosystem Studies Share Print E-Mail Caption Microorganisms like bacteria and algae grow in complex assemblages called biofilms -- the slimy coatings found on rocks in streambeds. These taxonomically diverse communities are essential to maintaining freshwater health. Credit Sylvia Lee Usage Restrictions To promote this press release. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.