Project: Chemical and Biological Characterizations of Phosphonate and Polyphosphate Dynamics in Marine Phytoplankton

Phosphorus (P) is a recognized essential nutrient for marine primary production and its inorganic chemistry has been well studied. However, the dissolved organic phosphorus pool (DOP) has been little studied even given its importance as a phosphorus source to microorganisms. This project will identify biogenic sources of P compounds to DOP using controlled culture studies focused on phosphonate and polyphosphate. These compound classes exert important controls over P cycling, carbon fixation and community structure and export from the upper ocean, and long-term sequestration. The study will employ innovative methods, including molecular tools and novel chemical analyses, to examine specific phosphonate and polyphosphate compound production by key phytoplankton taxa under different environmental conditions. Four hypotheses are driving the proposed research and focus the study on the primary research questions. The study will improve our understanding of the production of specific P compounds, and provide insight into the bioavailability of DOP and the influence of P on biological production.