1. U.S. Geological Survey Utah Cooperative Fish and Wildlife Research Unit Logan Utah USA
2. Department of Watershed Sciences Utah State University Logan Utah USA
3. The Ecology Center Utah State University Logan Utah USA
4. The Ecosystems Center Marine Biological Laboratory Woods Hole Massachusetts USA
5. Current Address Barnstable County Health Department Barnstable Massachusetts USA
6. Department of Ecology and Evolutionary Biology University of Michigan Ann Arbor Michigan USA