Berkeley Scientific Journal

Methyl halides are found in all of Earth’s biomes, produced naturally or through manmade means. Their presence in the atmosphere is problematic, as they catalyze depletion of stratospheric ozone. To understand the full environmental impact of these compounds, it is important to identify their chemical cycling processes. Iron increases methyl halide production in soils and oceans, yet copper’s influence remains unknown despite its similar chemical oxidation properties to iron. I experimentally tested the effect of copper sulfate and sunlight on methyl halide fluxes in San Francisco Bay seawater. Samples exposed to copper sulfate and sunlight averaged higher positive flux rates than other treatments. Copper sulfate also increased carbon dioxide production and acidification of the water. The interaction of copper sulfate and sunlight in seawater suggests a new mechanism for methyl halide production, most likely via a photochemical reaction or through suppression of normal uptake processes causing overabundant concentrations.