Researchers in Boat in Front of Dam (IMAGE) Cary Institute of Ecosystem Studies Caption Researchers collect fish samples in the tailwaters of the Glen Canyon Dam, Grand Canyon National Park. Credit Credit: US Geological Survey/Freshwaters Illustrated-Dave Herasimtschuk Usage Restrictions May be used to promote this press release. 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.