1. Department of Civil and Environmental Engineering Tufts University 200 College Avenue Medford Massachusetts 02155 USA
2. U.S. Geological Survey 12201 Sunrise Valley Drive Reston Virginia 20192 USA
3. Department of Fish, Wildlife, and Conservation Biology, and Graduate Degree Program in Ecology Colorado State University Fort Collins Colorado 80523 USA
4. Leetown Science Center S. O. Conte Anadromous Fish Research Center U.S. Geological Survey One Migratory Way, Turners Falls Massachusetts 01376 USA