Seminar: Effects of temperature and CO2-induced ocean acidification on calcification and extension rates of the tropical zooxanthellate scleractinian coral Siderastrea siderea

 Wednesday, November 30, 2011

3:00-4:00 p.m.

Venable Hall, Room G201

Anthropogenic elevation of atmospheric carbon dioxide (CO2) has led to an increase in the temperature and acidity of the oceans. Future increases in atmospheric CO2 are predicted to increase seawater temperatures by an additional 2 to 3°C and to reduce seawater pH by 0.3 to 0.4 units over this century. These global scale changes in ocean temperature and chemistry are predicted to have increasingly negative impacts on the health of coral reefs and may lead to increasing rates of coral mortality. We show that over approximately the last three decades on the Mesoamerican Barrier Reef System in the western Caribbean Sea, coral skeletal extension rates within forereef colonies of the reef-building coral Siderastrea siderea declined with increasing seawater temperature, while extension rates of backreef and nearshore colonies were not impacted. In addition, we explored the effects of temperature and CO2-incuded ocean acidification on the calcification of S. siderea reared for 60 days across a range of temperatures and acidities. Our results indicate that although calcification rates of S. siderea coral colonies were suppressed under elevated seawater temperature, these corals are able to calcify at a faster rate under CO2-acidified conditions projected for the next century. These findings reveal how corals have responded thus far to recent anthropogenic warming, offer insights into how they are likely to respond to future warming and acidification, and suggest that rising seawater temperature, rather than ocean acidification, is the more immediate threat to coral reefs.


Karl D. Castillo
Postdoctoral Fellow
UNC-CH Dept. of Marine Sciences

Reception follows immediately after the seminar.
Held in the Lobby on the 3rd floor of Venable Hall


The University of NC @ Chapel Hill, Poster.

  • Reset


OA-ICC Highlights

%d bloggers like this: