UC Santa Cruz
End of the line: using behavior and movement to inform conservation and management of terrestrial salmon consumers in the north Pacific
- Author(s): Wheat, Rachel E.
- Advisor(s): Wilmers, Christopher C
- et al.
The inherent conflict between the economic value of Pacific salmon (Oncorhynchus spp.) to fisheries and their importance to ecological systems has influenced the development of ecosystem-based fisheries management (EBFM), a new management paradigm that addresses the effects of fisheries on non-target species. However, poor understanding of the impacts of human competition with wildlife consumers of fish has hampered implementation of EBFM. While myriad processes may or may not be included in EBFM, no management endeavors will be achievable without a broader scientific knowledge base regarding cross-boundary salmon ecosystem impacts. This dissertation extends the concept of EBFM in Pacific salmon ecosystems to include consideration of ecosystem components in terrestrial habitats. First, I evaluate the extent of regulatory noncompliance with harvest regulations among subsistence fishers. I find that overharvest is correlated with fishers with low incomes and those providing for large households, as well as Alaska Natives adhering to traditional cultural practices. Second, I examine human disturbance and accessibility of salmon to wildlife by exploring how both habituation to and fear of human activity drive the foraging ecology of brown bears. During a study at a heavily used recreational and ecotourism site, non-habituated bears were active almost exclusively at night in human-dominated areas, likely leading to suboptimal foraging. Additionally, I test a novel method for microsatellite genotyping via collection of residual bear saliva on partially consumed salmon carcasses, finding it to be an efficient and effective method for monitoring brown bear populations. Finally, I assess the influence of the heterogeneity of anadromous fish systems on the behavior of bald eagles. Using data from 28 individual eagles tracked with GPS transmitters between May 2010 and January 2016, I find evidence of four distinct movement strategies among eagles in the north Pacific. The highly variable anadromous fish system of the north Pacific coast likely contributes to behavioral plasticity in bald eagles in this region and results in a range of movement strategies in the population.