[en] Existing literature illustrates inconsistent responses of seagrasses to oil exposure, both in the field and in the laboratory. Here, we add a new study that combined morphometric, demographic and photophysiology assessments to determine the potential oiling impacts to eelgrass (Zostera marina) from the 2007 Cosco Busan event in San Francisco Bay. Shoot densities, reproductive status, and rhizome elongation of Z. marina were examined at sites with pre-spill data, and eelgrass photosynthetic efficiency was measured post-spill. Shoot densities and percent elongation of rhizome internodes formed after the oil spill varied but with no consistent relationship to adjacent shoreline cleanup assessment team (SCAT) oiling categories. Similarly, differences in seagrass photosynthetic efficiency were not consistent with SCAT oiling categories. While thresholds for negative impacts on seagrass in general remain to be defined, conclusive oiling indicators for degree and duration of exposure would be important considerations and need examination under controlled study. - Highlights: • A review of papers spanning 54 years describing the effect of oiling on seagrass revealed inconsistent findings. • Eelgrass was evaluated following the Cosco Busan oil spill in San Franciso Bay approximately three weeks after the event. • No relationship was found between oil exposure and eelgrass rhizome growth, shoot density or electron transport rate. • Controlled studies of oil exposure and seagrass responses are needed to define exposure limits for each seagrass species.