Potential for Microbial Consumption of Marine Hydrocarbons

Coal Oil Point, an active marine seep in the Santa Barbara Basin, contributes a constant supply of hydrocarbon gases –methane, ethane, propane, and butane—into the water column which creates plumes of dissolved hydrocarbon gas. In these plumes, hydrocarbon consuming organisms can utilize the gas as substrate and remove these gases from the water column. By tracking the dissolved hydrocarbon plume in real time, samples can be collected for both microbial activity and dissolved gas concentration analysis.  To measure the rate of microbial consumption, tritiated hydrocarbon tracers are injected into the samples and incubated. Knowing the initial radioactivity of the tracer and the radioactivity of the products produced, through the microbial oxidation, the rate of consumption can be determined. With ever increasing concern of greenhouse gas pollutants, developing methods to determine the rate of microbial oxidation and how it controls ocean gas emissions, can help refine current atmospheric greenhouse gas budgets.