Use of rapid assessments of fishery bycatch of Humboldt penguins <i>Spheniscus humboldti</i> in Peru and Chile to help identify conservation priorities.

Abstract

The Humboldt penguin (<i>Spheniscus humboldti</i>) is a threatened species endemic to the Humboldt current system along the coasts of Peru and Chile. The species faces numerous and significant threats contributing to its declining population among which one of the most concerning is incidental catch (i.e. bycatch) by small-scale fisheries. 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 landing sites (ports, coves and fishing villages) in Peru and Chile. A total of 779 fishers were surveyed. Results showed an estimated total of 4067 (±889 s.d.) 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 revealed that larger mesh sizes (3-5 in (7.6 - 12.7 cm)) and certain target species, such as corvina drum (<i>Seriolella violacea</i>) and Peruvian grunt (<i>Anisotremus scapularis</i>), were strongly associated with reported bycatch events. This research underscores the urgent need for targeted conservation strategies, including bycatch mitigation measures, policy reforms and bi-national collaboration.