School of herring (IMAGE) University of Oldenburg Caption Herring are known for forming huge schools. Here, a shaol near Heligoland in the North Sea is shown. However, stocks in the western Baltic Sea are declining sharply. Credit Ture Tempelmann Usage Restrictions Only to be used in connection with press release and with appropriate credit. 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.