THE EFFECTS OF OIL SEEPS ON TRACE METAL CONCENTRATIONS IN SOUTHERN CALIFORNIA WATERSHEDS

Naturally occurring oil seeps can be found throughout California watersheds. Although natural, these seeps infuse crude oil into terrestrial and marine ecosystems, introducing organic and inorganic contaminants (e.g., PAHs, metals) that threaten aquatic life. Many studies have assessed the environmental impacts from marine oil spills. However, there is limited research on terrestrial oil seeps in riparian habitats. We hypothesize that (1) oil seeps introduce metals

directly into water and sediments, and (2) the presence of oil seeps in a channel changes the redox geochemistry of creek sediments and water, which may liberate even more metals. This redox shift happens when microbes use oxygen to consume the organic carbon in oil. In this project, we are analyzing water samples from six oil seep-impacted locations in Southern California to determine the effects of oil seep contamination on water chemistry. Future work will include measuring the concentration of metals in oil samples and stream sediments.