1. Department of Resource and Environmental Management, Simon Fraser University, 622 Strand Hall Annex 8888 University Dr. Burnaby, B.C. Canada V5A 1S6
2. Hakai Institute, PO Box 309, Heriot Bay, B.C. Canada V0P 1H0
3. Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, B.C. Canada V6T 1Z4
4. Department of Biology and Friday Harbor Laboratories, University of Washington, 620 University Road. Friday Harbor, WA USA 98250