A scientific framework for evaluating coral reef resilience to climate change
Barkley, Hannah C.
MetadataShow full item record
The 21𝑠𝑡 century warming and acidification of tropical oceans will impact the structure and function of coral reef ecosystems. Consequently, conservation efforts are increasingly focused on identifying and protecting reef communities that demonstrate resilience to these changes. In this thesis, I develop a scientific framework for identifying climate change resilience in coral communities and, using Palau’s coral reefs as a case study, demonstrate the application of this approach. First, I use coral skeletal records to evaluate the sensitivity of coral communities to episodes of severe thermal stress. This information reveals coral reef communities that consistently exhibit weak responses to multiple high temperature events. Second, I evaluate coral reef community structure across a strong, natural pH gradient using metrics informed by laboratory ocean acidification studies. The coral communities of Palau’s Rock Island reefs show a level of pH tolerance that is unique amongst reefs studied to date. Third, I conduct laboratory and field experiments to constrain the pH thresholds of these resilient corals and investigate potential mechanisms for pH tolerance. Finally, I combine archipelago-wide coral temperature and pH sensitivity data to construct climate change resilience indices. My study succeeds in identifying a small number of coral communities that have the potential to withstand 21𝑠𝑡 century climate change and highlights the spatial variability in community responses to ocean warming and acidification. Critically, I present a set of scientific tools and approaches for identifying resilient coral reef communities that has applicability to coral reefs worldwide.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2016
Suggested CitationThesis: Barkley, Hannah C., "A scientific framework for evaluating coral reef resilience to climate change", 2016-09, DOI:10.1575/1912/8427, https://hdl.handle.net/1912/8427
Showing items related by title, author, creator and subject.
Coral calcification : insights from inorganic experiments and coral responses to environmental variables Holcomb, Michael (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-02)Coral calcification is examined using a laboratory model and living corals. In the laboratory model, abiogenic aragonite formed at high saturation state (Ω>~20) had a granular appearance and was enriched in trace elements, ...
Coral biomineralization, climate proxies and the sensitivity of coral reefs to CO2-driven climate change DeCarlo, Thomas M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2017-02)Scleractinian corals extract calcium (Ca2+) and carbonate (CO2−3) ions from seawater to construct their calcium carbonate (CaCO3) skeletons. Key to the coral biomineralization process is the active elevation of the CO2−3 ...
Drenkard, Elizabeth J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2015-02)Global climate models project a 21st century strengthening of the Pacific Equatorial Undercurrent (EUC). The consequent increase in topographic upwelling of cool waters onto equatorial coral reef islands would mitigate ...