1. Vermont Cooperative Fish and Wildlife Research Unit, Rubenstein School of Environment and Natural Resources University of Vermont 81 Carrigan Drive, 302 Aiken Center Burlington Vermont 05405 USA
2. School of Marine Sciences University of Maine 5741 Libby Hall Orono Maine 04469 USA
3. Rubenstein School of Environment and Natural Resources University of Vermont 81 Carrigan Drive, 308D Aiken Center Burlington Vermont 05405 USA
4. U.S. Geological Survey, Vermont Cooperative Fish and Wildlife Research Unit, Rubenstein School of Environment and Natural Resources University of Vermont 81 Carrigan Drive, 302 Aiken Center Burlington Vermont 05405 USA