Production and Fate of Acrylate in Seawater

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For more than thirty years, oceanographers and atmospheric scientists have studied dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) because they form the basis of a biogeochemical system that transfers sulfur from the oceans to the atmosphere, affecting the Earth?s radiation balance and climate. Through these studies, we have learned that DMS and DMSP also significantly impact the ecology and chemistry of the oceans. The intensive effort to understand the marine biogeochemistry of DMS(P) has revealed that their cycling is much more complex than first imagined, but it has also caused us to largely overlook a highly interesting and important component of the DMS(P) cycle, namely acrylate, a product formed from the degradation of DMSP via DMSP lyase. Surprisingly little is known about acrylate concentrations, fluxes, or impacts in the oceans, even though concentrations and fluxes should at times be substantial, especially during blooms of DMSP-rich algae that are common throughout the world?s oceans and often harmful or toxic. In this study, researchers at the SUNY College of Environmental Science and Forestry will conduct a three-year laboratory and field study to examine several fundamental aspects of the marine acrylate cycle. The main objectives of the proposed research are: (1) to determine the kinetics and wavelength dependence for the photolysis of acrylate in contrasting oceanic waters; (2) to determine cellular and dissolved acrylate concentrations in axenic algal cultures and evaluate how these concentrations change in response to nutrient or light stress and growth stage; and (3) to determine dissolved and particulate acrylate concentrations, photolysis rates, and biological loss rates in contrasting oceanic water through participation in two Gulf of Mexico research cruises. Broader Impacts: Results from this study are expected to significantly improve our fundamental understanding of the marine acrylate cycle and its impact on the biogeochemistry of the upper oceans. The project will establish and foster research and educational collaborations for these students, especially the graduate students, through several avenues including participation at national and local meetings, mentoring, preparing for and delivering college-level lectures, and presentations made to the general public at forums such as Syracuse?s Milton J. Rubenstein Museum of Science. Two graduate students and a visiting Chinese scholar will be trained as part of this project, along with several undergraduates. Finally, the PI will participate in several activities to promote and foster education including serving as an NSF STEM mentor, co-coordinating Chemistry Day at the NY State Fair, giving oral presentations at local K-12 schools, and mentoring SUNY ESF Environmental Science and Chemistry students.