Climate-related shifts in phytoplankton assemblages may have profound implications for oceanic feedbacks on the atmosphere, and for human use of marine resources. Particular algal groups are largely responsible for crucial processes like vertical carbon export, biogenic calcification and silicification, production of climatically active gases like dimethylsulfide (DMS), and for sustaining food webs that lead to economically valuable higher trophic levels. The Drs. Hutchins and DiTullio will investigate potential climate change impacts on algal community structure and biogeochemistry during the North Atlantic Spring Bloom, a regime that is ideal for determining how changing ocean conditions may affect both calcareous and siliceous algae. The PIs will work closely with CarboOcean a major European Union funded activity led by investigators from the Alfred Wegener Institute. This will include exchanges of cruises between the two groups, collaborative shipboard experiments, and modeling efforts using joint results. Graduate student and post-doctoral training will be included as part of the interdisciplinary and international activities.