Biofilm Community (IMAGE) Cary Institute of Ecosystem Studies Caption Biofilms are complex communities composed of algae, fungi, and bacteria all living and working together. In streams, biofilms contribute to water quality by recycling nutrients and organic matter. They are also a major food source for invertebrates, which, in turn, feed larger animals like fish. Credit Photo credit: Sylvia Lee Usage Restrictions To promote this press release License Licensed content 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.