Streams are interesting aquatic systems. (IMAGE) University of Helsinki Caption Streams are interesting aquatic systems that harbour diverse life forms, from fishes or insects to microbes. Diatoms are one of the most diverse primary producers in streams and play an important role in ecosystem functioning and oxygen production. This stream from Majorca included in this study. Credit copyright: Bryan Kennedy Usage Restrictions copyright: Bryan Kennedy License Original 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.