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Genetic Connectivity and Phenotypic Plasticity of Shallow and Mesophotic Coral Ecosystems in the Gulf of Mexico

Coral reef ecosystems worldwide are facing increasing degradation due to
disease, anthropogenic damage, and climate change, particularly in the Tropical Western
Atlantic. Mesophotic coral ecosystems (MCEs) have been recently gaining attention
through increased characterization as continuations of shallow reefs below traditional
SCUBA depths (>30 m). As MCEs appear to be sheltered from many stressors affecting
shallow reefs, MCEs may act as a coral refuge and provide larvae to nearby shallow
reefs. The Deep Reef Refugia Hypothesis (DRRH) posits that shallow and mesophotic
reefs may be genetically connected and that some coral species are equally compatible in
both habitats. The research presented here addresses key questions that underlie this
theory and advances our knowledge of coral connectivity and MCE ecology using the
depth-generalist coral Montastraea cavernosa. Chapter 1 presents an overview of the
DRRH, a description of MCEs in the Gulf of Mexico (GOM), and the framework of
research questions within existing reef management infrastructure in the GOM. Through microsatellite genotyping, Chapter 2 identifies high connectivity among shallow and
mesophotic reefs in the northwest GOM and evidence for relative isolation between depth
zones in Belize and the southeast GOM. Historical migration and vertical connectivity
models estimate Gulf-wide population panmixia. Chapter 3 focuses on population
structure within the northwest GOM, identifying a lack of significant population
structure. Dominant migration patterns estimate population panmixia, suggesting
mesophotic populations currently considered for National Marine Sanctuary protection
benefit the Flower Garden Banks. Chapter 4 quantifies the level of morphological
variation between shallow and mesophotic M. cavernosa, revealing two distinct
morphotypes possibly representing adaptive tradeoffs. Chapter 5 examines the
transcriptomic mechanisms behind coral plasticity between depth zones, discovering a
consistent response to mesophotic conditions across regions. Additionally, variable
plasticity of mesophotic corals resulting from transplantation to shallow depths and
potential differences in bleaching resilience between shallow and mesophotic corals are
identified. The dissertation concludes with a synthesis of the results as they pertain to
connectivity of shallow and mesophotic corals in the Gulf of Mexico and suggests future
research that will aid in further understanding of MCE ecology and connectivity. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Identiferoai:union.ndltd.org:fau.edu/oai:fau.digital.flvc.org:fau_40861
ContributorsStudivan, Michael (author), Voss, Joshua (Thesis advisor), Florida Atlantic University (Degree grantor), Charles E. Schmidt College of Science, Department of Biological Sciences
PublisherFlorida Atlantic University
Source SetsFlorida Atlantic University
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation, Text
Format256 p., application/pdf
RightsCopyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder., http://rightsstatements.org/vocab/InC/1.0/

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