Database Analyisis Of Coral Population Distibutions In The Caribbean Region, 200 Ka To Present
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Concern for the future of coral reef ecosystems has motivated scientists to examine the fossil record to predict changes in coral distribution and population health. Specifically, in regions of concern, such as the Caribbean,a compilation oflong-term records of coral reef health and biogeographic change during climate perturbations are can provide usefuldata for conservation efforts. The Caribbean coral reef record through the last 200,000 years (Pleistocene and Holocene) provides a good indicator of general reef construction. For this thesis, Ihavecompiled a database of dominant reef corals across the Caribbean from 200 ka to present, which documents how species have been distributed over the last four sea level highs and their associated climatic changes. The presence and habitat of different coral species around the Caribbean and their changes over time can indicate both dominant morphological preferences and environmental controls on species distribution. Here, we found that the three main reef builders, Acropora palmata, Acropora cervicornis, and Montastraea “annularis”, have distinct reef zonation and distribution throughout the Pleistocene and Holocene. Changes from these typical distributions, like a contraction of the A. palmataduring the marine isotopic stage 5e(125,000 ka), show an influence of a cold, northern sea surface temperature and rapid sea level rise on A. palmata production. A species turnover from Montastraea nanycito M. “annularis” reflects replacement during an extinction of M. nanyci around 82,000 ka. These changes in species ranges and reef location show the susceptibility of these Monstastraeato niche absences and morphological changes. The recent history of coral responses to sea-level and climatic change provides the best understanding for how reefs will adapt to future alterations in temperature and carbon dioxide levelsand anthropogenic activity. Knowing what changes to expect in the composition and structure of reef ecosystems will be a critical tool to help prevent, or mitigate large-scale ecosystem collapse of coral reefs in the future.