Light Intensity, Nutrient, and pCO2 Controls on Boron Isotope Fractionation in Laboratory Cultured Corals

Columbia University, New York NY

Investigators

Abstract

ABSTRACT OCE-0083061 Boron isotopes, sensitive to the carbonate system, may be an important tool in understanding coral chemistry and has the intriguing possibility of tracking changes in pCO2, whether it be global changes over long time scales or a record of internal 'carbon pool' conditions mediated by the coral itself. For this reason, the PI will determine the boron isotopic composition for two separate sets of cultured coral samples to increase our knowledge on the uptake and fractionation of boron isotopes. One suite of coral samples cultured under controlled light intensity and nutrient conditions will address whether the interpretation of observed seasonal variation in the boron isotopic composition of a natural coral is correct. The second set of corals grown under specified temperature and pCO2 levels, will address the influence of these two parameters on the boron isotopic composition, as well as specifically answer the question as to whether boron isotopes in corals can be used as a paleo-pH proxy. The potential application of boron isotopes as a proxy for pH may provide further insights into our understanding of global changes in pCO2 over glacial/interglacial time scales, and thus ocean-atmosphere interactions and global climate change.