Facial recognition technology isn’t just for humans. In Hong Kong, it is now being embraced to protect an endangered species of coral reef fish. In a world first, researchers at the University of Hong Kong have created a facial recognition app to identify individual humphead wrasse fish. The highly prized fish – listed as endangered on the International Union for Conservation of Nature’s Red List of Threatened Species since 2004 – is considered a delicacy among affluent diners in Hong Kong and can cost as much as US$850 a kilo (US$385 per pound). Called Saving Face, the free app – due for release next month – uses humpheads’ unique eye markings to help enforcement officials, as well as members of the public and restaurateurs, distinguish between legally and illegally traded fish. “Our research found that you can identify individual humpheads by the incredibly intricate markings on the sides of their face,” says HKU marine biologist Yvonne Sadovy, comparing the complex markings to fingerprints. Named for its bulbous forehead, the humphead can grow up to two metres in length and take four to five years to reach adulthood in the wild, but most are sold as juveniles. Being slow to mature, often caught before reaching adulthood – and having a high market value – makes the species vulnerable to overfishing, and has prompted concerns about the sustainability of its exploitation. In 2005, the species was placed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, to regulate the global trade through the issuing of export permits by source countries to ensure trade in the species would not negatively affect its population. Indonesia is the only legal exporter of the humphead wrasse, and Hong Kong is a major importer, with much of it re-exported to mainland China. How Hong Kong is decimating fish stocks with its appetite for seafood HKU’s Loby Hau Cheuk-yu, a driving force behind the app project, says Hong Kong restaurants stocking the species can only sell a restricted quota and must display a possession licence, as required by the Agriculture, Fisheries and Conservation Department (AFCD), that also requires vendors to record any trade in the species, including buying and selling the fish between vendors and to customers. But because there is no physical tagging of individual fish, Hau says sellers can easily replenish stocks with illegally sourced and undocumented humpheads that are smuggled into Hong Kong with shipments of other fish. “AFCD enforcement officers have no way of keeping track of their numbers,” Hau says. “This lack of tracking and traceability of individual fish creates a major enforcement challenge because of the inability to distinguish between legally and illegally imported fish.” Sadovy says retail outlets in Hong Kong that replenish their legally imported humphead stock through unofficial channels are engaging in laundering. “Our research clearly shows that there are far more fish on sale in retail outlets in Hong Kong than the number of legal imports,” she says. Sadovy says a united effort is needed to make the app work, with education a key factor, adding that the app project received funding from the Ocean Park Conservation Foundation, Hong Kong. Images of legally imported humpheads will be uploaded by AFCD officials to a database connected to the app. If enforcement officers or diners want to check the legality of a humphead that they see at a market or in a restaurant’s live seafood tank, they can photograph the fish and, using the app, check for matches with fish profiles stored in the database. Users can also report suspicious fish to the AFCD. “Allowing the public to report suspicious specimens means we can have more eyes on the ground and better monitor the potential illegal trade in this endangered species,” she says.