Sampling Lakes (IMAGE) University of Washington Caption Study lead Matthew Bogard, a University of Washington postdoctoral researcher, samples water from Canvasback Lake in Yukon Flats National Wildlife Refuge. Credit Matthew Bogard/University of Washington Usage Restrictions Photo credit required. 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.