Species conservation is typically founded upon a range of management strategies, which integrate both biological and socioeconomic data. In this thesis, population genetics, acoustic telemetry, spawning aggregation surveys and stakeholder assessments were used to address key knowledge gaps limiting effective conservation management for critically endangered Nassau grouper (Epinephelus striatus) stocks in The Bahamas. A panel of polymorphic microsatellite markers was optimised to assess the genetic population dynamics of more than 400 Nassau grouper sampled throughout the country. Microsatellite data indicate that contemporary Nassau grouper populations in The Bahamas are predominantly genetically diverse and weakly differentiated, but lack geographic population structure. Assessments of changes in effective population size (Ne) show substantive reductions in Ne within The Bahamas compared to historic values that are likely due to natural disturbances. Evidence for recent bottlenecks occurring in three islands as well as an active spawning site, along with higher inbreeding coefficients in two islands were also found, and can be attributed to more recent anthropogenic activities. Collapse of a historically important Nassau grouper fish spawning aggregation (FSA) was supported by both acoustic telemetry and spawning aggregation survey dives. Restriction-site-associated DNA sequencing (RAD-seq) of 94 Nassau grouper was used to explore intraspecific population dynamics, loci under selection and patterns of gene flow in The Bahamas. Genomic assessments of diversity were in accord with microsatellite data and examinations of gene flow support higher levels of connectivity in The Bahamas than was previously suggested. The increased resolution gained from assessments of genomic data support intraspecific population structuring that may be driven by differences in gene flow and putative loci under divergent selection. Telemetry data were successfully used to identify the origins of spawning adults, and support demographic connectivity through migrations between an active FSA in the central Bahamas and home reef habitats within the Exumas and a no-take marine protected area. Stakeholder assessments highlight the complexities of fisheries management within The Bahamas, with key stakeholders often exhibiting conflicting opinions regarding the status of Nassau grouper and the efficacy of management options. However, these groups mutually agree upon the need to better manage remaining Nassau grouper stocks within The Bahamas through science-grounded policies. Synthesis of these studies along with a review of fisheries governance in The Bahamas was used to develop a comprehensive national management plan for Nassau grouper to facilitate better conservation for remaining populations of this ecologically important marine species.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:744052 |
| Date | January 2018 |
| Creators | Sherman, Krista Danielle |
| Contributors | Tyler, Charles ; Stevens, Jamie ; Simpson, Stephen D. |
| Publisher | University of Exeter |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10871/33061 |
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