Also alarming to some is the sheer brutality of shark-finning itself: After the fins are sliced off, the sharks are often thrown back into the ocean to die.

Increasing concerns about the impact of shark finning have prompted governments to take action. Though the practice of shark finning had already been banned in the United States, in 2011, several states, including Hawaii, California and Washington, enacted broader laws to prohibit the possession, sale or distribution of shark fins. In 2012, Taiwan introduced new fishing laws banning shark finning, making it the first government to ban the practice in Asia.

But in mainland China, powerful trade groups like the China Hotel Association have so far been unmoved. Environmentalists have been pressing the association to withhold its “green hotel” stamp of approval from members that serve shark fin. Zhang Jingfu, assistant to the chairman of the China Hotel Association, said the group encouraged businesses to reduce sales of shark fin but was not prepared to do more. “The sales and consumption of shark fins are market-driven behavior, and the hotel association cannot force the industry or consumers to stop,” he said in an e-mail.

Still, there are signs that the conservation campaign, whose most prominent advocate is the retired National Basketball Association star Yao Ming, is gaining momentum. In September, conservationists scored a major victory when Cathay Pacific Airlines announced that it would no longer carry shark fin and most other shark products in its cargo shipments. Environmental groups estimate that Cathay Pacific transported up to half of the total 650 tons of shark fin imported by air into Hong Kong last year. Though Cathay Pacific’s shipments accounted for only a small fraction of the overall 10,200 tons of shark fin estimated to have been imported into Hong Kong in 2011, the decision by a major airline to abandon the shark fin trade was still touted by environmentalists as a bold signal to the rest of the industry in Hong Kong, which is still the world’s leading trade hub for shark fins.

Last July, the Chinese government announced a ban on shark fin soup at official banquets. Though Xinhua, the state news agency, said the ban would take up to three years to implement, conservation groups have been heartened. In December, officials in Shanghai even allowed environmental activists to gather outside an anti-shark finning art exhibit as part of a petition drive against shark fin consumption.

Just as important, environmentalists say eating shark fin is starting to acquire a stigma among the Chinese elite.

“Many of the most successful men and women in China’s business community are beginning to realize that shark fins are not nutritious after all,” said Cai Tao, brand director of China Entrepreneur Club, an exclusive group that includes Jet Li, the kung fu star turned philanthropist, and Jack Ma, founder of the Internet business giant Alibaba Group. Members of the club pledged in 2009 to forgo shark fin soup and to prohibit it from being served at their own sponsored events. Also in 2009, Taobao.com, the popular e-commerce subsidiary of Mr. Ma’s Alibaba Group, announced a ban on the sale of shark fins through its site.