Sharks on a plane: Large shark fin seizure shines light on shark exploitation

Abstract

One of the biggest threats to sustainability of shark populations is overexploitation due to high global market demand for fins, meat, skin, and cartilage. Current laws designed to regulate the worldwide trade in certain shark species have not stemmed illegal and unreported trade. In January 2020, United States Fish and Wildlife Service (USFWS) wildlife inspectors seized an illegal shipment of shark fins at the Miami airport during an inspection of an in-transit shipment from South America to Asia. The shipment contained over 5000 fins, placing it among the largest seizures in the US to date. We utilized a combination of morphological and genetic analyses to evaluate species diversity of the sharks targeted for this illegal shipment. Morphological identification of pectoral (n = 2435) and dorsal (n = 1301) fins revealed over 50 % were obtained from CITES Appendix II species, including silky shark (Carcharhinus falciformis), great hammerhead (Sphyrna mokarran), and scalloped hammerhead (Sphyrna lewini). A random subset of dorsal fins (n = 149) was sampled from each of the CITES species and the tiger shark (Galeocerdo cuvier) fins (n = 49), to confirm our morphological identifications using genetic data. In addition, a subset of morphologically unidentified fins (n = 192) was genetically identified to estimate species diversity of the fins not identified by morphological analysis. The genetic results revealed 11 additional species for a total of 14 species identified within the shipment. The data from the genetic and morphological analysis of this case will be used to inform ongoing investigations of the origin of this illegal shipment, as well as future investigations of shark fisheries undergoing exploitation for the shark fin trade.