A campaign against shark fin soup in China has proved remarkably effective. Government and industry statistics show that the demand for shark fins has plunged. And this could have wider implications for other endangered wildlife.

A delicacy served to honoured guests, and also a sign of social status.

But shark fin soup is no longer so popular.

A coalition of celebrities has been involved in the campaign to promote public awarenesses about the shark trade, including former NBA star Yao Ming.

As Chinese people are becoming more aware of wildlife conservation, eating shark fin soup is no longer fashionable. The government has also set up a campaign against extravagance, banning the soup from official banquets.

May Mei is the chief representative in China of Wildaid, an NGO working for wildlife protection. She told me the effects of the campaign have been dramatic.

"The change is huge in China, especially now. Last year, after the Chinese government released a three-year ban on eating sharp fin soup, the decline is huge. The consumption declined by 50 to 70 percent in the past two years. We are really proud that people are doing the right thing." said May Mei.

Millions of sharks are killed each year to supply the demand for shark fin soup. As a result, a third of the world's shark species are facing extinction. So, there is urgent need to educate people to change.

When the buying stops, the killing will stop too. Progress has been impressive, but the campaign will continue.