DNA-based species identification of shark finning seizures in Southwest Atlantic: implications for wildlife trade surveillance and law enforcement

Abstract

Sharks developed life history traits that make them susceptible to overfishing. This is, in turn, a risk for extinction, and several species are affected. The high price of shark fins in the international trade has triggered the widespread capture of sharks at unsustainable levels, prompting illegal and unethical practices, such as finning. To address these concerns, the present study aimed to identify species composition using molecular techniques based on DNA barcoding and DNA polymorphism on samples taken from illegal shark fin seizures conducted by the Federal Environmental Agency of Brazil. A species-specific DNA-based identification from three finning seizures in Brazil found at least 20 species from 747 shark fins, some of which were identified as endangered and protected under Brazilian legislation, while others were representative of restricted catches, according to Appendix II of CITES. In the seizure from Belém, 338 fins were identified as belonging to at least 19 different species, while in the seizure from Natal 211, fins belonging to at least 8 different species were identified. Furthermore, 198 fins from Cananéia were identified through PCR-Multiplex as belonging to Isurus oxyrinchus. These results raise concerns about the environmental and socioeconomic effects of finning on developing countries. Furthermore, this study represents the first finning evaluation from Brazil in the Southwest Atlantic, highlighting the importance of developing policies aimed toward restricting and regulating the shark trade and detecting IUU fisheries and illegal trade of endangered species, mainly in developing countries, where fisheries management, surveillance, and species-specific fisheries catch data are often sporatic.