Mon, 09/18/2023 - 12:40pm Skidaway Leanne Powers Chemistry SUNY College of Environmental Science and Forestry Dr. Leanne Powers Faculty Page Seminars Thinking beyond carbon to better understand marine organic matter reactivity: Sources and distribution of non-volatile halogenated organic matter in the ocean Marine dissolved organic matter (DOM) is one of Earth’s major carbon reservoirs and is arguably its most dynamic. On the other hand, radiocarbon measurements suggest that majority of marine DOM is stored for millennia in the deep ocean as refractory dissolved organic carbon (RDOC). Thus, it is often assumed that RDOC, and marine DOM more generally, can persist for thousands of years, but this generalization ignores differences in marine DOM sources, complexity, and reactivity throughout different ocean regions. In fact, despite years of intensive study, pathways and rates of DOM production and removal are still poorly constrained. In this talk, we will discuss why RDOC may not be as stable as we currently assume, and explore a largely ignored component of the marine DOM pool – nonvolatile halogenated DOM. While the focus on carbon sequestration is justified, the links between carbon cycling and halogen biogeochemistry have not been established in terms of DOM research even though it is well known that abiotic and biological processes can convert halides into reactive halogen species. We will therefore discuss why halogenated DOM may be a large and reactive component of the overall DOM pool, which could provide new insights into DOM reactivity.
