1. U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201, United States
2. U.S. Geological Survey, Western Fisheries Research Center, 6505 NE 65th Street, Seattle, Washington 98115, United States
3. U.S. Geological Survey, Eastern Ecological Science Center, 11649 Leetown Road, Kearneysville, West Virginia 25430, United States