A coalition of marine conservation groups and high-profile environmentalists has written to the government calling for a formal ban on serving shark fin at all official functions.
The letter, whose signatories include Virgin Group boss Richard Branson, oceanographer Jacque Cousteau's grandson Fabien and filmmaker Ric O'Barry, follows an outcry after images of thousands of shark fins drying on a Hong Kong rooftop were published this month.
The pictures and a video watched more than 300,000 times on YouTube spotlighted Hong Kong's pivotal role in the shark fin industry, which sees the fins of an estimated 73 million sharks traded a year.
Representatives of nearly 60 firms and green groups including Greenpeace, the Hong Kong Shark Foundation, Animals Asia, the Humane Society International, WWF Hong Kong and the SPCA, signed the letter, accusing the government of inaction.
Although an unofficial ban is already in place on serving shark fin at government banquets, the coalition calls for a formal ban "at all official functions across the public sector".
Criticising the response to the rooftop images, the letter says: "Despite voices raised in protest in Hong Kong and elsewhere, the response received from the Agriculture, Fisheries and Conservation Department, or indeed anyone else in the government, has been lacking.
"The Hong Kong government continues to hide behind CITES."
Trade in only three threatened shark species is restricted under rules set by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, a measure the coalition argues lags behind science and falls short of anti-finning measures in the US, Europe and Pacific island nations.
"The reality is that by September 2012, 54 per cent of 263 shark species assessed for their conservation status were identified by the International Union for Conservation of Nature as at risk of extinction either now or in the near future," the letter said.
"Another 214 species had been assessed at that time, but were found to be data deficient … This means that at least one in three shark species are known to be at risk and in all likelihood the figure is higher."
The coalition's letter was presented to Undersecretary for Environment Christine Loh Kung-wai at a forum with green groups on Friday.
A spokeswoman for the environment secretary said a formal response would be sent to the coalition, but stressed the government had introduced a policy of no shark fin at banquets for a number of years. In a written response, she indicated that the government felt it was meeting its conservation obligations and preferred consumer education to any ban on the consumption of shark fin.