Scientific Diving Success Story: Sharmila Giri

Sharm Giri is a Ph.D. candidate in Marine Geology and Geophysics at the University of Miami Rosenstiel School of Marine and Atmospheric Science. She is growing corals in elevated concentrations of calcium and magnesium and measuring Mg/Ca in the skeletons, tissues and symbionts. Since the concentration of Mg and Ca in seawater has changed throughout time and Mg/Ca is often used as a paleotemperature proxy in corals, Sharm is testing whether the ratio of these elements is affected by their concentration in seawater at a constant temperature. Sharm’s longer term goal is to use the same corals to test the Mg inhibition hypothesis for the evolution of coral-algal symbiosis using Mg/Ca, Ca isotopes, genetics and organic geochemistry. While her work does not currently involve SCUBA diving, it will soon.

During Sharm’s experiments, corals are kept in these glass jars, in which the chemistry of the seawater is changed by adding more calcium or magnesium.

Sharm changing water in jars that coral is in. Because seawater is not circulating within these jars, water needs to be changed every day.

Replicates of Pocillopora damicornis. This species is used in experiments because of its fast growth rate.