Gwynns Run Tributary in Baltimore, Md. (image) Cary Institute of Ecosystem Studies Caption Researchers collect water samples for chemical analysis from the Gwynns Run tributary. Credit Steward T.A. Pickett, Baltimore Ecosystem Study LTER Usage Restrictions Can be used to promote this press release. 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.