Coral calcification : insights from inorganic experiments and coral responses to environmental variables
MetadataShow full item record
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, similar to centers of calcification and dark bands in corals. Abiogenic aragonite formed fibrous crystals at lower saturation states, similar to crystals which radiate out from centers of calcification. These similarities suggest the calcifying environment of the coral experiences a range of saturation states. To estimate when high or low saturation states occur within the coral, living corals were stained, staining patterns suggest dark bands form between dusk and dawn. A model is proposed in which daytime saturation state is limited by the availability of CO2. To test the potential for photosynthesis to limit CO2 availability to calcification, corals were grown under altered CO2 and nutrient levels. Elevated CO2 levels decreased calcification in zooxanthellate corals, however addition of nutrients reduced the negative impact of CO2. This suggests nutrient availability may limit photosynthesis under elevated pCO2 conditions. The effects of nutrients, CO2, and temperature were further tested on both zooxanthellate and azooxanthellate coral colonies. Unexpectedly, a gender difference was found in the effect of CO2 on calcification.
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 2010
Suggested CitationThesis: Holcomb, Michael, "Coral calcification : insights from inorganic experiments and coral responses to environmental variables", 2010-02, DOI:10.1575/1912/3197, https://hdl.handle.net/1912/3197
Showing items related by title, author, creator and subject.
Variations in coral reef net community calcification and aragonite saturation state on local and global scales Bernstein, Whitney N. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2013-09)Predicting the response of net community calcification (NCC) to ocean acidification (OA) and declining aragonite saturation state (Ωa) requires a thorough understanding of controls on NCC. The diurnal control of light ...
Porites coral calcification responses to declining Ωar in a CO2 manipulation experiment in Palau versus the calcification responses observed in ten other studies of massive Porites corals Cohen, Anne L (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-08-02)Porites coral calcification responses to declining Ωar in a CO2 manipulation experiment in Palau versus the calcification responses observed in ten other studies of massive Porites corals. For a complete list of measurements, ...
The origin and role of organic matrix in coral calcification: insights from comparing coral skeleton and abiogenic aragonite DeCarlo, Thomas M.; Ren, Haojia; Farfan, Gabriela A. (Frontiers Media, 2018-05-15)Understanding the mechanisms of coral calcification is critical for accurately projecting coral reef futures under ocean acidification and warming. Recent suggestions that calcification is primarily controlled by organic ...