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“Movers and Stayers” Movement Ecology of Yellowtail Snapper Ocyurus chrysurus and Horse-eye Jack Caranx latus Around Buck Island Reef National Monument, U.S. Virgin IslandsNovak, Ashleigh 09 July 2018 (has links)
When movement ecology of target species is coupled with spatial management approaches, such as marine protected areas (MPAs), the results can establish effective conservation outcomes. Nevertheless, a knowledge gap persists regarding how many marine organisms use specific environments over long, continuous periods of time. Acoustic telemetry arrays and fine-scale positioning systems are quickly pervading the marine environment as they can monitor animal movements on a near continuous basis, filling in many previous unknowns on spatial use patterns. Further, coupling fine-scale movement patterns and benthic habitat data provides a spatial framework foundation essential to understanding the intricacies of how habitats can drive movement ecology, and how organisms might link adjacent habitats and resources through movement. The first chapter of this thesis quantified both the broad- and fine-scale movement patterns of yellowtail snapper Ocyurus chrysurus (n = 8) around Buck Island Reef National Monument (BIRNM), St. Croix, U.S. Virgin Islands, an MPA managed by the National Park Service. High site fidelity and a clear affinity to the western shelf break characterized common broad-scale movements observed for this species. Two distinct contingents were detected by the positioning system suggesting individuals were using habitats in two unique, highly structured ways, however, this result requires further validation through an increased sample size. For the second chapter, I characterized the broad-scale movement ecology of horse-eye jack Caranx latus (n = 7), an understudied, but common predatory reef fish. Horse-eye jack are wide ranging, with most individuals visiting almost all receivers (n = 78) in the BIRNM array network. Comparatively, horse-eye jack made more frequent BIRNM boundary crossings into adjacent MPAs harboring various levels of protection. Taken together, these two case studies highlight how sympatric reef species differentially use space within BIRNM and highlight the necessity of evaluating MPA efficacy across species and over longer time scales. Constructing single species movement assessments is essential information, yet there is now a demonstrated need for community movement studies. The final chapter of this thesis highlights promising next steps for this project, including the proposal of a new hourly or sub hourly movement trajectory analysis, potentially capable of elucidating species interactions in near real-time. Together, this thesis not only fills data gaps on species deficient in ecological studies (horse-eye jack) but illuminates individuality in habitat and space use (yellowtail snapper), and how these analyses can be tied back in to developing stronger holistic community population assessments. With continued exploitation of marine environments and increasing anthropogenic demand of marine resources, the need for understanding processes driving species movements is essential in developing successful spatial management plans.
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