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Current Research and Research Interests

M.S. Thesis:

Effects of Increasing Carbon Dioxide on the Calcification rate of  Scleractinan Coral

Biomineralization, the biological formation of a mineral based skeleton, by scleractinian corals provides the foundation for one of the most diverse ecosystems: the tropical coral reefs.  As atmospheric CO2 rises and dissolves in the ocean, it increases the acidity of the water and lowers the available levels of carbonate needed for corals to create their skeletal framework.  Conservative CO2 emission models show the pH of oceans worldwide is predicted to decrease by 0.2 to 0.3 by the year 2100 which translates to an approximate doubling of the acidity of oceanic waters.  Although it now is well established that the effect of rising atmospheric CO2 results in a decrease in the mass deposition of the calcium carbonate skeleton made by reef corals (Langdon, 2001), virtually nothing is known regarding the effects on coral morphology or the microstructure of the underlying skeleton. 
Skeletal microstructure has also been shown to act as a phenotypically plastic trait (sensu Bruno & Edmunds, 1997).  Therefore, mass deposition (g cm-3) rates in corals could be traded against skeletal structure in response to rising CO2, through the simultaneous altering of both porosity and linear extension.  My research aims to test whether linear extension rates are maintained at the expense of the skeletal structure or alternatively, if linear extension rates are reduced enough to result in an increase in skeletal density.  Either outcomes would have serious implications regarding the competitive ability of coral and their resistance to physical degradation.

Research interests:

Ecology

• climate change effects on tropical coral reefs
• coral reef ecology
• marine symbioses

Physiology

• calcification and growth rates of marine organisms
• morphological plasticity

Expected Graduation : Winter 2007/2008

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