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dc.contributor.authorRaymond, Wendel W.
dc.date.accessioned2021-10-22T18:06:26Z
dc.date.available2021-10-22T18:06:26Z
dc.date.issued2020-08
dc.identifier.urihttp://hdl.handle.net/11122/12320
dc.descriptionThesis (Ph.D.) University of Alaska Fairbanks, 2020en_US
dc.description.abstractThe recovery of sea otters (Enhydra lutris) to Southeast Alaska is a conservation success story, but their increasing population raises questions about sea otter population dynamics and the ecological role of this top-level predator. In Chapter 1, we addressed these questions by investigating patterns and population effects of subsistence sea otter harvest. Subsistence harvest reduced populations at a small scale, with potential to slow or stop population growth, but across Southeast Alaska the population continues to grow, even with an average 3% subsistence harvest rate. In Chapters 2 and 3 we investigated the ecological role of sea otters in seagrass (Zostera marina) communities. When we tested for generality in a sea otter - seagrass trophic cascade across a large spatial scale in Southeast Alaska, we found a positive relationship between sea otters and seagrass. However, we found no evidence of a relationship between crabs and epifauna, suggesting that the ecological mechanisms in Southeast Alaska may differ from other regions. Our comparison of carbon and nitrogen stable isotopes (SI) to assess the role of sea otters on trophic structure and energetic pathways of seagrass beds found little effect of sea otters in overall community trophic niche space, suggesting similar carbon sources and food chain length in seagrass meadows regardless of sea otters. Conversely, the FA profiles of diverse consumer suggest variation in dietary sources with and without sea otters. This result suggests that the trophic cascade may not be the only or primary energetic pathway in Southeast Alaska seagrass communities. In all, our studies have revealed that sea otters in Southeast Alaska are linked to both people and a common Southeast Alaska nearshore habitat, seagrass. These results describe the varied interactions of a recovering top predator and highlight a need to consider these diverse interactions in resource management, conservation, and ecological research.en_US
dc.description.sponsorshipAlaska Sea Grant (project R/111-03), National Oceanic and Atmospheric Administration (grant NA14OAR4170079), National Science Foundation Biological Oceanography grant (#1635716), Coastal Science, Engineering and Education for Sustainability (SEES) grant (#1600230), National Science Foundation Graduate Research Fellowship, North Pacific Research Board Graduate Student Research Award, American Fisheries Society Steven Berkeley Marine Conservation Fellowship, Lerner-Grey Fund for Marine Researchen_US
dc.description.tableofcontentsGeneral Introduction -- Chapter 1: Location specific factors influence patterns and effects of subsistence sea otter harvest in Southeast Alaska -- Chapter 2: Testing the generality of apex predator-mediated trophic cascades in seagrass meadows -- Chapter 3: Sea otter effects on trophic structure of seagrass communities in Southeast Alaska -- General Conclusion -- Appendices.en_US
dc.language.isoen_USen_US
dc.subjectSea otteren_US
dc.subjectEcologyen_US
dc.subjectSoutheast Alaskaen_US
dc.subjectHabitaten_US
dc.subjectSeagrassesen_US
dc.subjectFood chainsen_US
dc.subject.otherDoctor of Philosophy in Fisheriesen_US
dc.titleSea otters in Southeast Alaska: subsistence harvest and ecological effects in seagrass communitiesen_US
dc.typeThesisen_US
dc.type.degreephden_US
dc.identifier.departmentDepartment of Fisheriesen_US
dc.contributor.chairEckert, Ginny L.
dc.contributor.committeeBeaudreau, Anne H.
dc.contributor.committeeGalloway, Aaron W.E.
dc.contributor.committeeMueter, Franz J.
refterms.dateFOA2021-10-22T18:06:27Z


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