1. Department of Wildlife Fisheries and Conservation Biology, University of Maine, Orono, ME, 04469, USA
2. NOAA National Marine Fisheries Service, Maine Field Station, 17 Godfrey Drive, Orono, ME, 04473, USA
3. Department of Life Sciences, University of Trieste, Edificio M, Via Licio Giorgieri 10, Trieste 34127, Italy
4. U.S. Geological Survey, Maine Cooperative Fish and Wildlife Research Unit, University of Maine, Orono, ME 04469, USA