Cohen Lab

Hydrography and Coral Communities

Physical and chemical hydrography, nutrient and carbon dynamics, and the response of coral communities on Dongsha Atoll, South China Sea.

 PI’s: George T.F. Wong, Shih-Ji Kao (Academia Sinica) and Anne L. Cohen (Woods Hole Oceanographic Institution)

 This study is a collaborative, in situ investigation of the responses of the shallow-water tropical coral reef ecosystems to the interactive effects of ocean acidification, ocean warming and dissolved inorganic nutrients. Our study site, Dongsha Atoll, an isolated coral reef atoll in the Northern South China Sea, provides an ideal location to test several hypotheses regarding the response of reef-building coral communities to changes in multiple, co-varying factors that on their own, are known to influence calcification. On Dongsha, the most energetic internal waves in the world’s ocean shoal onto the reef, turbulently mixing deep, cool waters with high pCO2, low pH and nutrients across the pycnocline into the surface mixed layer where the corals live. It is hypothesized that the varied nutrient, pH and temperature- conditions in three sub-regions, namely, the waters north of the Atoll, in the central lagoon and south of the Atoll, may provide a range of combinations of environmental conditions for a comparative study for assessing these effects. The coral reef ecosystems around Green Island in the nearby northwestern Pacific will be used as a reference site. The primary purposes of this sub-project are three fold: (1) to provide the basic physical and chemical hydrographic data for defining the environmental characteristics of the study site; (2) to assess the nutrient and carbon dynamics in the three sub-regions around the Dongsha Atoll; (3) to assess the responses of the corals to the varied suites of environmental conditions in the sub-regions and 4) To quantify net ecosystem calcification rates of communities in the three sub-regions of the atoll.  Fieldwork begins June 2013.

Funding for this research is provided by TheGovernment of Taiwan through a grant to Academia Sinica and subcontract to Woods Hole Oceanographic Institution, The National Science Foundation (NSF OCE-1220529) and an NSF Graduate Research Fellowship to Thomas Mario DeCarlo.

Last updated: June 17, 2013