Simulating Coral Calcification in the Lab: Impact of Ocean Acidification and Rising Temperature

Ocean Acidification Initiative Project



Coral reefs form some of the most diverse ecosystems on Earth and have tremendous ecological and economic values. As the key process to the health of these ecosystems, coral calcification is affected by the ocean acidification and rising temperature induced by anthropogenic CO2 emission. Most of our current understanding of the impact of these environmental changes on coral reef calcification derives either from laboratory manipulation experiments in which corals are removed from natural habitat and reared under controlled conditions or from in situ measurements of calcification response of selected reef ecosystem. It however remains unclear whether results from these studies can be widely applied to estimate the impact of ocean acidification and rising temperatures on coral reef calcification, because coral calcification responses may differ between lab culture and natural systems and may vary among different species and reefs. Clearly, accurate predictions of the coral calcification responses will depend on a robust understanding of the fundamental processes that are involved in coral calcification.

We herein propose to conduct chemical precipitation experiments to simulate coral calcification process in the laboratory, determine ‘calcification’ rates under different temperature and pCO2/pH conditions, and quantitatively evaluate the effects of several key variables of coral calcification (e.g., enzyme activity, seawater exchange and membrane diffusivity) on its calcification rates. To our best knowledge, this proposed study constitutes the first set of chemical precipitation experiments that are specifically designed to systematically simulate coral biocalcification and to examine the responses of calcification rates to changing seawater conditions. It will open new opportunities not only for studies of coral calcification but also for research in many other fields (e.g. development of oceanographic paleo-proxies based on coral skeleton).