Publication Date:
2022-05-25
Description:
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 February 2015
Description:
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 warming locally and modulate the intensity of coral bleaching. However, EUC water is potentially more acidic and richer in dissolved inorganic nutrients (DIN), both widely considered detrimental to coral reef health.
My analysis of the Simple Ocean Data Assimilation product indicates that the EUC has indeed strengthened over the past 130 years. This result provides an historical baseline and dynamical reference for future intensification. Additionally, I reared corals in laboratory experiments, co-manipulating food, light and CO2 (acidity) to test the role of nutrition in coral response to elevate CO2 conditions: Heterotrophy yields larger corals but CO2 sensitivity is independent of feeding. Conversely, factors that enhance zooxanthellate photosynthesis (light and DIN) reduce CO2 sensitivity. Corals under higher light also store more lipid but these reserves are not utilized to maintain calcification under elevated CO2. My results suggest that while mitigation of CO2 effects on calcification is not linked to energetic reserve, EUC fueled increases in DIN and productivity could reduce effects of elevated CO2 on coral calcification.
Description:
NSF grants OCE-1220529, OCE-1041106,
OCE-1031971, OCE-1233282, and OCE-1041052; the MIT Bermuda Biological Research
Station Fund, the WHOI Oceans Venture Fund, and the EAPS Student Research Fund.
Keywords:
Coral bleaching
;
Coral reef ecology
Repository Name:
Woods Hole Open Access Server
Type:
Thesis
Format:
application/pdf
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