Image caption Images of tens of thousands of shark fins drying on a Hong Kong factory roof caused controversy in January

Hong Kong's government has announced it will stop serving shark fin and bluefin tuna at official functions, in a move lauded by conservation groups.

In a statement, it said it would also encourage government-funded bodies to do the same.

According to the World Wildlife Fund, demand for the fins and other shark-related products has led to some shark species falling in numbers by 60-70%.

Hong Kong is one of the world's biggest markets for shark fin.

However, imports have declined - attributed in part to a clampdown on lavish official functions on the Chinese mainland, the final destination for many of the imports.

The population of Pacific bluefin tuna has dropped an estimated 96% since the 1950s.

Another delicacy, black moss - also known as fat choy - whose harvesting is blamed for desertification and erosion in certain areas, has also been banned at official Hong Kong functions.

In a press release, the government said it was taking the step because the items "have aroused international and local concern because they are either captured or harvested in ecologically unfriendly or unsustainable ways, or cause other conservation concerns".

'Decade of campaigning'

Image caption Shark fin traders say their sales have been hurt amid protests by environmental groups

The move was hailed by conservation groups.

"After almost a decade of advocacy in the form of petitions, protest marches, letter writing and media campaigns, the Hong Kong government has finally seen fit to do the right thing - for which we applaud them," Alex Hofford, the executive director of Hong Kong-based marine conservation group MyOcean, told AFP news agency.

"We hope the citizens of Hong Kong can follow suit and finally lay this abhorrent tradition to rest," Mr Hofford said.

Last year, tens of thousands of shark fins found drying on a factory rooftop in Hong Kong - in an apparent attempt to hide the increasingly controversial items from public view - caused an outcry among conservationists.

The anti-shark fin campaigns have prompted some five-star hotels in the Chinese territory to remove shark fin from their menus, as well as flagship carrier Cathay Pacific.