1. Department of Fish, Wildlife, and Conservation Biology; Colorado State University; Fort Collins Colorado 80523 USA
2. U.S. Geological Survey; Colorado Cooperative Fish and Wildlife Unit; Fort Collins Colorado 80523 USA
3. Department of Statistics; Colorado State University; Fort Collins Colorado 80523 USA
4. National Marine Mammal Laboratory; Alaska Fisheries Science Center; NOAA; 7600 Sand Point Way NE Seattle Washington 98115-6349 USA
5. Statistics in Ecology, Environment and Conservation; Department of Statistical Sciences; University of Cape Town; Rondebosch 7701 Cape Town South Africa
6. African Climate and Development Initiative; University of Cape Town; Rondebosch 7701 South Africa
7. School of Aquatic and Fishery Sciences; University of Washington; Box 355020 Seattle Washington 98161-2182 USA