Diatom biofilms on pebbles (IMAGE) University of Southern Denmark Caption Diatoms are growing on pebbles in pond. They can be seen as brownish biofilms. C Credit Stief et al/University of Southern Denmark Usage Restrictions w credit 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.