1. Department of Environmental Science and Technology, University of Maryland, College Park, Maryland 20742, United States
2. U.S. Geological Survey California Water Science Center, Sacramento, California 95819, United States
3. U.S. Geological Survey Patuxent, Wildlife Research Center, Beltsville, Maryland 20705, United States
4. U.S. Geological Survey Oregon Water Science Center, Portland, Oregon 97201, United States