Seabirds, Plankton and Climate Change (image) University of California - Davis Caption Seabirds like this Antarctic prion are the top predators of the Southern Ocean, feeding on krill that themselves feed on phytoplankton. New research shows that a chemical signal released by plankton, dimethyl sulfide or DMS, attracts seabirds that eat krill. DMS also plays a role in regulating the planet's temperature by influencing cloud formation. Credit Copyright Kevin Shafer, 2007. Usage Restrictions May be used with acknowledgement of the copyright owner. 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.