Pre-export shark fin processing to conceal CITES-listed species: a case-study from a shark fin seizure in Colombia

Illegal trade in shark fins can be a driver of overexploitation and is a global law enforcement issue given that some frequently traded species are listed on CITES Appendix II. Shark fins are usually traded dried or frozen and are not processed until they reach supply chain end points in southeast Asia, which allows for visual species identification in many of the commonly traded species. All external tissue is removed during processing, eliminating characters that are crucial for visual species identification. If processing occurs early in the supply chain, law enforcement personnel face the challenge of identifying fins to the species level and detecting illegal trade without the ability to do so visually. Here, we apply mini-barcoding and real-time PCR methods to a case study in Colombia where seized processed shark fins were sampled and analyzed using these methods. Five species of shark were identified, all of which are listed under CITES Appendix II, and four of which have been assessed to be in threatened categories by the IUCN Red List of Threatened Species. Threatened and CITES-listed species comprised 96.3% and 100% of the analyzed samples, respectively. The case study presented here raises concerns about the changes occurring when processing takes place in the supply chain, impeding any kind of identification of illegally traded shark fins without genetic tools. If early-supply chain processing becomes the norm, it will introduce significant identification challenges for law enforcement throughout the rest of the supply chain. This underscores the need for in-port genetic testing capacity building in nations and regions where shark products are highly traded to detect CITES-listed and prohibited/regulated species at any point of the supply chain and regardless of the nature of the product.