Abstract

This study investigates the interactions between South American sea lions (Otaria byronia) and trawling fisheries in central-southern Chile, using underwater video technology. From August 2017 to August 2018, a total of 32 underwater filming sessions were conducted across trawl fisheries targeting Patagonian grenadier (Macruronus magellanicus), nylon shrimp (Heterocarpus reedi), and Chilean hake (Merluccius gayi gayi). The records revealed a total of 15 sea lions, including adult and subadult males and females. These individuals were observed engaging in specific behaviors, such as swimming within the trawl nets and feeding at escape panels of bycatch reduction devices (BRDs). Notably, we documented one subadult male reaching 425 meters. This finding suggests a probable significant adaptability and potential predation behavior at extreme depths. Our findings highlight the importance of further monitoring and research to address conflicts between marine mammal populations and the fishing industry, while enhancing the of conservation strategies to ensure their effectiveness.