Anammox Bacteria (IMAGE) University of Southern Denmark Caption Purple area: This ocean water holds less than 10 percent oxygen. Blue area: The Oxygen Free Zone off Peru/Chile, where bacteria produce huge amount of nitrogen. Black Arrow: Ocean current that transports the bacteria through the Oxygen Minimum Zone. (Illustration: Bo Thamdrup/SDU). Credit Bo Thamdrup/SDU Usage Restrictions None 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.