1. Department of Fisheries and Wildlife Michigan State University East Lansing MI 48824‐1222 U.S.A.
2. Department of Integrative Biology Michigan State University East Lansing MI 48824‐1222 U.S.A.
3. Glacier Bay National Park and Preserve, P. O. Box 140 Gustavus AK 99826 U.S.A.
4. U. S. Geological Survey Alaska Science Center, 4210 University Drive Anchorage AK 99508 U.S.A.
5. Alaska Region U. S. Geological Survey, 250 Egan Drive Juneau AK 99801 U.S.A.