Shark hotspot: Drivers for distribution and conservation in a tropical oceanic archipelago of the Atlantic Ocean

Abstract

Sharks play an essential role in maintaining the health of ecosystems, but many species are endangered and have locally disappeared around the world. Their management, where established Marine Protected Areas (MPAs) and strict fishing regulations exist, has contributed to the recovery and maintenance of shark populations. However, the overlap between shark populations and increasing human activities can result in incidents and socioenvironmental conflicts. The present study used data from baited remote underwater video systems, citizen science, drones, and scientific captures to identify drivers of shark distribution around the Fernando de Noronha Archipelago (FNA), a tourist destination offshore Brazil. Our findings place FNA among the world’s shark aggregation spots for both richness and abundance. They also show that both environmental (reef, trophic level, sea turtle grounds) and anthropogenic variables (fishing grounds, diving sites, beaches) are important predictors of shark distribution, signaling strong overlap and competition with humans for space and resources. This intensive space sharing is also corroborated by a species distribution model developed for tiger sharks. Furthermore, it is shown that the home range of adults and some species extend beyond its limits into areas where fishing is allowed with restrictions. Therefore, this study proposes an extension of the limits of the MPA and methods for human-shark interaction mitigation. The island’s economy strictly depends on ecotourism and these conservation measures are essential for a sustainable future to both sharks and humans.