Los Angeles: An emotional battle over a traditional soup has split California's Chinese-American community as environmental and animal welfare groups push the legislature to ban the sale and possession of shark fins.

The ban bill passed the Assembly last month, 65-8, but is running into trouble in the Senate.

The fight has pitted influential Chinese-American politicians against one another, some of whom are running for mayor of San Francisco. Chinese traders and restaurant owners have hired lobbyists to oppose a ban, and bus-loads of Chinatown residents have descended on the Capitol in Sacramento, saying that a ban would violate cultural customs.

Houston Rockets basketball star Yao Ming has joined other celebrities, such as Leonardo DiCaprio and Scarlett Johansson, in public support of a ban.

"Remember, when the buying stops, the killing can too," says Ming, in a YouTube video that shows him pushing away a bowl of soup.

Shark fin soup, which can cost as much as $80 (Dh293.8) a serving in restaurants, has been a Chinese delicacy for hundreds of years and is often served at weddings and banquets. It is a status symbol, considered to have medicinal properties, and its defenders see its consumption as a fundamental cultural right.

But Assemblyman Paul Fong, a sponsor of the bill, said he "grew up on shark fin soup" but only recently realised "anything that is unhealthy, that the culture is practising, we should stop doing it".

"We used to bind women's feet and that was unhealthy for the woman."

Scientists say the fin trade has contributed to catastrophic declines of shark populations, threatening to disrupt ocean ecosystems, leading to diminishing fish stocks for human consumption.