Filter Closeup (IMAGE) University of Washington Caption The researchers pump water past a filter, shown here, that collects any solid material floating in the stream. Back at the UW, the team did DNA sequencing on the collected material to detect the presence of salmonid species. Credit Elizabeth Andruszkiewicz Allan/University of Washington Usage Restrictions With credit License Original 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.