A major new study has revealed extensive illegal trade in endangered shark species, exposing critical gaps in international wildlife protection. Published today in Science Advances, the research uncovers widespread non-compliance with CITES – the global treaty meant to safeguard threatened species – within one of the world’s most lucrative marine markets.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regulates global trade in wildlife products among 185 signatory nations. Under the treaty, species listed on Appendix II can be traded only if proven legal and sustainable, while Appendix I species are banned from commercial trade altogether.

Yet the latest findings suggest that these rules are being routinely flouted in the global shark-fin market, particularly in Hong Kong – demarcated as the epicentre of the international shark-fin trade.

Led by researchers from Mote Marine Laboratory, Florida International University, and the Wildlife Conservation Society (WCS), the study presents sobering evidence that critically endangered sharks – such as hammerheads and oceanic whitetips – continue to appear in Hong Kong markets. And in alarming numbers.

“Oceanic whitetip fins are 70 times more common in the trade than documented by CITES, and hammerheads are 10 times more common,” said Dr. Demian Chapman, co-author of the study. “It has been this way since 2014, and unless countries take stronger action, these species may be doomed.”

Using DNA barcoding on more than 16,000 shark fins collected between 2015 and 2021, the team found fins from CITES-listed species in 6.5% of all samples – significantly above what governments officially report. In one striking case, fins from the Critically Endangered oceanic whitetip shark appeared 70 times more frequently than reported to CITES, indicating that over 95% of trade in the species is likely illegal.

“CITES is the strongest global tool we have to ensure wildlife trade isn’t driving species toward extinction,” said Luke Warwick, Director of Shark and Ray Conservation at WCS.

“When it’s implemented properly, it works. Green turtles were once critically endangered under Appendix I, but strong enforcement halted their trade, allowing populations to rebound. That’s the power of CITES. For sharks like the oceanic whitetip, we need the same level of commitment – now.”

The research further underscores Hong Kong’s continued role as a global shark-fin hub, including for species banned from international trade. Despite DNA evidence linking traded fins to specific countries, many of those same nations reported zero exports of the listed species – pointing to major failures in reporting, enforcement, and traceability.

“This study reveals a systemic failure to uphold existing protections,” said lead author Dr. Diego Cardeñosa. “Critically endangered shark parts are still crossing borders in large volumes despite more than a decade of international safeguards.

“The science is clear: CITES can stop trade-driven extinctions, but only if countries enforce it.”

Supported by the Shark Conservation Fund, this collaborative study builds on years of work by WCS, government agencies, NGOs, and academic partners to strengthen global governance of marine wildlife trade.

As CITES delegates gather this month for CoP20, the findings serve as a stark reminder: without stronger enforcement and accountability, the world’s most threatened sharks may vanish from the oceans entirely.

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