Dolphin Mercury (IMAGE) Johns Hopkins University Caption Sue Hunter, the National Aquarium's director of animal programs and marine mammals, examines a resident dolphin. Credit George Graul/National Aquarium 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.