Sources and Sinks of Methyl Halides in the Florida Everglades and Coastal Waters

Portland State University, Portland OR

Investigators

Abstract

Recent studies have shown that methyl halides (methyl chloride-CH3Cl and methyl bromide-CH3Br) are produced in significant quantities by phytoplankton and by photochemical oxidation of dissolved organic matter (DOM). However, little is known about the mechanisms responsible for the photochemical production of methyl halides and the factors which affect the microbial formation and consumption in the surface waters. Scientists from Portland State University will carry out laboratory experiments to determine the mechanisms responsible for the photochemical and microbial formation and consumption of CH3Cl and CH3Br in the Everglades, a coastal wetland. Specifically, the study will focus on (1) quantifying and characterizing the temporal and spatial variability of methyl halide fluxes from a coastal wetland; (2) identifying the mechanisms responsible for the photochemical production of methyl halides; (3) examining the role of algal mats on the formation and consumption of methyl halides; (4) using stable isotopes to identify the sources and sinks for methyl halides within various ecotones of the Everglades and coastal waters; and (5) delineating sources and sinks using stable isotope analysis. This research will yield new insights on the biological and photochemical production of methyl chloride and methyl bromide in a coastal wetland which may bring this science community one step closer to balancing the budget for these two methyl halides. One graduate and one undergraduate student will be supported and trained as part of this project.