Checking Fish (IMAGE) Duke University Caption Sarah Diringer, a PhD student at Duke University, examines fish samples from the Madre de Dios River for potential human mercury exposure. Credit Sarah Diringer, Duke University 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.