Collaborative Research: Understanding Environmental and Ecological Controls on Carbon Export and Flux Attenuation near Bermuda

The research supported by this award will quantify transport of Carbon into, and Carbon’s fate within, the mesopelagic zone (200 – 1000m depth) at the Bermuda Atlantic Time Series Site (BATS). Chemical, biological, and physical measurements at BATS will be combined with a mechanistic model designed to identify key controls on the export of organic carbon into these intermediate depths. The over-arching goal of the model-data synthesis is to identify and understand controls on the C-flux pathways . In this project, a data-guided model will be used to compare the relative importance of particle sinking, mixing of dissolved organic carbon, and active transport by organisms. Broader impacts include a video game, visits to/from a charter school which serves students from communities underrepresented in Geosciences, supervision of undergraduates via the Woods Hole Partnership Education Program, advising of one graduate student, and of one postdoc. Both PIs are female early-career scientists, one from a group underrepresented in Oceanography. A mechanistic biogeochemical model capable of assimilating key metabolic and physiological rates and stocks of zooplankton and heterotrophic bacteria in the mesopelagic zone (200-1000 m) will be constructed, evaluated, and utilized with the goal of quantifying and comparing fluxes of particle sinking, mixing of dissolved organic carbon (DOC), and active export, by diel vertical migration of zooplankton, of respiratory CO2, particles and DOC. In addition, the fate of organic carbon in the mesopelagic will be characterized by comparing bacterial versus zooplankton respiration. Characterization of the relative magnitudes of these fluxes will provide a view of environmental and ecological controls on export pathways and on the ultimate fate of organic carbon exported from the euphotic to the mesopelagic zone at this location. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.