Illegal artisanal longline use in the Galapagos Marine Reserve characterized through monitoring and control data

Andres Romero-Caicedo^1*Paola Buitron-Lopez²Andres Tapia-Jaramillo³Simon McKinley¹Edwin Castro-Briones¹Gonzalo Sevilla-Cedeño²John Ronquillo-Garzon²Gabriel Maciel de Souza Vianna¹

• ¹Charles Darwin Foundation, Puerto Ayora, Galápagos, Ecuador
• ²Galapagos National Park Directorate, Puerto Ayora, Ecuador
• ³Independent consultant, Puerto Ayora, Ecuador

Illegal longline fishing in the Galapagos Marine Reserve (GMR) represents a socioecological issue with significant impact on protected marine species. This study characterizes the use of illegal longlines in the GMR by analyzing datasets from monitoring and control operations by the Galapagos National Park Directorate. We explored temporal and spatial patterns of longline detections, identified impacted species, and estimated compliance of vessels associated with longlines. The number of longlines detected varied across years but no clear seasonal pattern was evident. The most frequently captured taxa were sharks and rays, including critically endangered scalloped hammerheads (Sphyrna lewini) and endangered manta rays (Mobula birostris). The critically endangered waved-albatrosses and green turtles (Chelonia mydas) were also captured. Longline fishing occurred frequently in the submarine canyon south of Isabela, the seamount east of Santa Cruz, and waters between Pinzon, Isabela, and Santiago Islands, which are areas of high productivity and popular fishing grounds. Longlines were also recorded near Darwin and Wolf Islands, a hotspot for shark conservation. Offending vessels represented 17% of the artisanal fleet targeting pelagic fish and were responsible for ~30% of landings. Notably, 80% of trips when longlines were recorded had no associated fisheries landing. Offending vessels had their Automatic Identification Systems (AIS) deactivated in 69% of trips with longlines, despite their use being legally required. These findings provide baseline data to help GMR managers improve enforcement allocation and underscore the importance of strengthening surveillance and enforcement to mitigate illegal fishing.