Figure 1 (IMAGE) University of California - San Diego Caption Mean dissolved oxygen concentrations in the world's oceans at a depth of 400 meters (1,312 feet) with blue contours representing the lowest concentrations. Boxed areas represent ocean regions analyzed in the study. Credit AAAS/Science 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.