The effects of visitor presence on zoo and aquarium animals have become increasingly well studied, using measures such as behavioral responses and exhibit usage. Many taxa remain underrepresented in this literature; this is the case for marine mammals, despite widespread public concern for their welfare in managed care settings. The current study therefore used behavioral activity budgets and exhibit usage to assess the responses of California sea lions (Zalophus californianus) and harbor seals (Phoca vitulina) to visitors at the Seal Cove exhibit at Six Flags Discovery Kingdom, Vallejo CA. Data was collected via focal follow video recordings over the summer season of 2016, and analyzed using MANCOVAs, discriminant analyses, and modified Spread of Participation Indices. The sea lions showed no significant changes in behavior when visitors were present, but did show greater preference for the water bordering visitor viewing areas during these times. Two sea lions gave birth during the study period, and showed greater preference for land areas both adjacent to and out of sight of visitors when nursing compared to while pregnant. In contrast, the harbor seals showed significant behavioral changes in the presence of visitors, including increased vigilance and feeding. This was associated with increased preferential use of water areas adjacent to the visitor viewing area. Visitors were able to purchase fish to throw to the animals, which likely contributed to the differences observed. Overall, this study found little evidence for negative visitor impacts on two pinniped species in a zoo setting.