Marine debris, in particular plastic debris and debris related to fishing activities, have an impact on marine mammals and seabirds. In marine-coastal species such as otariids, we can detect the incidence of these interactions through land-based observations. In this study, we recorded and described interactions between marine debris and the otariids Arctocephalus australis and Otaria byronia in a natural protected area in Peru, according to age class categories. Between 2016 and 2020, we recorded 151 animals that were directly impacted and/or were observed interacting with marine debris. Residual collars from fishing gear, ropes, plastic bags and unidentified material were recorded. Direct interactions with debris at colonies (e.g., plastic bags) were also recorded, as well as animals evidenced interacting with hooks. The age class category and species with the highest number of individuals impacted by residual collars were adult female A. australis and subadult male O. byronia. Single-use plastics were the most commonly bitten/moved waste by animals in the reserve. In the case of hooks, these were mostly lodged in the mouths of otariids. Our results highlight the importance of continuing to promote segregation at source, as well as the correct disposal of waste, locally and globally, to mitigate impacts on marine fauna.