Basketball star Yao Ming led his Houston team to four championship tournaments in America, but his greatest victory may be his work in China to save millions of sharks.

Yao joined a campaign in 2006 to ban shark fin soup, which is a delicacy in his native China, and nine years later his involvement has been hailed as crucial in transforming Chinese attitudes about the tradition.

U.S. based conservation group WildAid recruited Yao as the face of its media blitz designed to make people aware of how their food habits were destroying shark populations around Asia.

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In a television ad, the star athlete is about to dine on soup. He hears that 70 million sharks are killed each year just for their fins, and looks up from his soup to see a wounded shark in an aquarium tank. He pushes his soup away in disgust and other people in the restaurant, watching him, follow his lead and do the same.

That's pretty much what happened in real life.

The campaign first gained traction during the 2008 Beijing Olympics, where Yao was a huge draw playing for the Chinese National Team in basketball.

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Yao's TV ad so moved Chinese businessman Jim Zhang, he turned into a full time environmentalist who successfully lobbied the National People's Congress (China's parliament) to ban ‘shark wing' soup, as it's called, from state banquets. Hong Kong, Malaysia and India did the same.

The cause became a centerpiece of Chinese social media, which led to five hotel groups, three shipping companies, and 24 airlines banning the transport or serving of the dish. Chinese television stations gave the WildAid's PSAs $11.6 million in free airtime.

By 2014, WildAid reported sales of shark fin soup had declined 82%, and nearly two-thirds of Chinese people credited awareness campaigns with their decision to quit eating the soup.

Maybe Yao's advocacy on behalf of the fierce fish came from his early days as a member of the pro basketball team in China — the Shanghai Sharks.

(WATCH the pivotal ad below – *Warning: contains image of wounded shark) – Photos by voyagedeslivres; World Economic Forum, CC