Rio de Janeiro coast identified as nursery for endangered sharks

Researchers from the Proshark Institute and the Federal University of Rio de Janeiro (UFRJ) have identified the Ilha Grande-Sepetiba estuarine complex on the coast of Rio de Janeiro as a potential nursery for three endangered shark species.

Published in the Brazilian Journal of Biology, the study documented six pregnant females: two spinner sharks (Carcharhinus brevipinna), two blacktip sharks (Carcharhinus limbatus), and two sand tiger sharks (Carcharias taurus). The presence of females at different stages of gestation suggests the 3,100 km² area serves as a critical site throughout the reproductive cycle.

Data was gathered between 2006 and 2024 through incidental fishing catches and scientific monitoring. Researchers utilized satellite telemetry and necropsies to evaluate embryo development and yolk content. The ecosystem, which includes mangroves and protected bays, provides the shelter and food variety necessary for pregnant females and pups, highlighting its importance for future marine conservation efforts.