Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.746192
Title: The role of marine protected areas in conserving highly mobile pelagic species
Author: Curnick, D. J.
ISNI:       0000 0004 7230 3174
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2016
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Abstract:
In this thesis I assess the efficacy of large no-take marine protected areas (MPAs), known as marine reserves, in safeguarding mobile pelagic predators. The creation of reserves excludes fisheries, so while removing a pressure, it also removes a key source of data on pelagic predators. Therefore, I also evaluate two fisheries-independent monitoring techniques: telemetry and camera trapping. I use the British Indian Ocean Territory (BIOT) marine reserve as a case study. In Chapter 2 I assess trends in tuna populations, showing that yellowfin tuna (Thunnus albacares) were declining in BIOT prior to the reserve’s creation. While there is no discernible signal of overall species recovery four years after reserve establishment, BIOT may house resident tuna populations. In Chapter 3 I evaluate environmental correlates of tuna distribution, identifying sea surface temperature and depth as drivers, and show that yellowfin and bigeye tuna (Thunnus obesus) occupy different spatial and thermal habitats. In Chapter 4 I investigate the reserve’s role in conserving silky sharks (Carcharhinus falciformis). From fisheries records I infer that BIOT may be an important nursery ground, and telemetry data show they have clear habitat preferences within BIOT. In Chapter 5 I examine the potential of using remote camera-traps to monitor populations of pelagic sharks and demonstrate that significant investment would be required to develop an effective array. Overall, I conclude that BIOT may have more conservation value to species like the silky shark than it does to pelagic tunas. I show that spatial-temporal distributions of pelagic predators are predictable, meaning that enforcement could be better directed in order to improve efficiency. I suggest actively removing drifting fish aggregation devices (FADs) in BIOT to improve its conservation value for silky sharks. Lastly, I recommend that managers wishing to monitor pelagic populations undertake full cost-benefit analyses of camera-trap techniques prior to implementation.
Supervisor: Collen, B. ; Jones, K. J. ; Koldewey, H. ; Kemp, K. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.746192  DOI: Not available
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