Use of rapid assessments of Humboldt penguin Spheniscus humboldti bycatch in Peru and Chile to help identify conservation priorities

The Humboldt penguin (Spheniscus humboldti) is a vulnerable species endemic to the Humboldt Current System along the coasts of Peru and Chile. The species faces significant threats, including habitat loss, invasive species, contamination, climate change, and fisheries bycatch, all of which contribute to its declining population. This study assessed the bycatch of Humboldt penguins in small-scale surface and bottom gillnet and purse-seine fisheries using fisher surveys conducted across 39 ports in Peru and Chile. A total of 779 fishers were surveyed. Results showed an estimated total of 4,067 (± 889) penguins caught in 2023, with the highest bycatch associated with gillnets. Ports such as Tambo de Mora and San José in Peru and Coquimbo and San Antonio in Chile reported the most significant interactions. Spatial mapping demonstrated that areas with the most common bycatch events coincide with locations of larger penguin colonies. Multiple Correspondence Analysis (MCA) revealed that larger mesh sizes (3–5 inches) and certain target species, such as corvina drum (Seriolella violacea) and Peruvian grunt (Anisotremus scapularis), were strongly associated with bycatch events. This research underscores the urgent need for targeted conservation strategies, including bycatch mitigation measures, policy reforms, and bi-national collaboration.