Research in the Cohen Lab focuses on climate change and its impact on ocean life. We are particularly interested in marine calcification, the biological production of calcium carbonate that produces both the tiniest seashells, and coral reef ecosystems so big they can be seen from space. Calcification is sensitive to changes in the biological, physical and biogeochemical environment in which it occurs and is therefore a valuable index of organism and ecosystem responses to change in the ocean. Importantly, calcified structures such as coral skeletons record that information as they grow, archiving events that occurred yesterday or many thousands of years ago. We develop and apply biological, oceanographic, geochemical and modeling tools and approaches in both laboratory-based and field experiments to gain an understanding of the fundamental processes of calcification, to identify the primary biological, physical and biogeochemical drivers of calcification and their interactions, and to develop new climate proxies that allow us to build records of ocean climate change spanning the past millenium.