On this Sunday afternoon on a crowded street of Mong Kok, one of Hong Kong’s most bustling districts, following a whistle, dozens of people jumped on a blue sheet, lying face down with card-board fins strapped to their backs, protesting in silence the practice of shark finning and expressing their will for Hong Kong to ban the sale of shark fins.

“I feel strongly about this cause,” says Theo Moodley, a 16-year-old South African who participated in the event. “I think people here will eventually get to realize the cruelty of shark finning and stop eating shark fins.”

Earlier this month, the California Senate passed a bill to ban the trade and possession of shark fins, joining Hawaii, Oregon and Washington as the fourth American state to pass such a bill. Around the same time, the Toronto City Council also voted to support a similar ban. Both California and Toronto have large Asian populations. And now, local environmental groups are urging Hong Kong, the world’s largest importer of shark fins and believed to handle at least half the global trade in shark fins, to follow this trend.

“The government should ban the trade of shark fins,” says Bertha Lo Ka-yan, the project director of Hong Kong Shark Foundation , the group that organized the Sunday event. “If depending only on common people, it will be difficult and will take a long time to make any difference,” she says, noting from the current speed of consumption of shark fins, sharks could be extinct in 10 years.

Interestingly, most participants of the event were foreigners. “Hong Kong people are a bit more self-conscious, a bit shy,” says Lo, “but I have received calls from many locals asking what they can do to support our cause.”

But banning shark fins in Hong Kong would mean a significant damage to local shark-fin traders. Calling the four American states and Toronto “a very few irrational societies,” Ricky Leung, a committee member of Hong Kong Marine Products Import and Export Association, says he doesn’t understand their decisions. “I’ve been in this industry for so many years. I know very well that sharks are limitless to catch. I’m very confident that sharks are enough to be supplied in a long time.

The trade of shark fins should not be banned all over the world. Shark meat, shark bones, medicine and cosmetics made of shark oil and purses made of shark skin are popular globally. Why did they only ban shark fins?”

Leung says local shark-fin traders are practicing according to the international agreement, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), where only three species of sharks – namely basking shark, great white shark and whale shark – are included as endangered, and the trade of these species should be tightly controlled, while the rest of the species can be traded freely.

But Silvy Pun Yuen-yiu, the marketing officer of WWF Hong Kong , argues that although CITES only includes three endangered species of sharks, on the International Union for Conservation of Nature (IUCN)’s red list of threatened species, the species of sharks increased from 15 in 1996 to 181 last year.

Daniel Chui Tak-yiu, the executive director of Fook Lam Moon, a local restaurant known for its shark-fin cuisines, says even if Hong Kong banned shark fins, it still would not help much, because the mainland is the biggest consumer of shark fins, and the whole shark-fin business could go underground, or Macau could take the place of Hong Kong as the trade centre.

With the rapid economic growth in mainland China, its demand for shark fins has also been growing rapidly. Statistics show that about 80 percent of shark fins in Hong Kong are to be exported into the mainland.

Surprisingly, even though opposing the ban of shark fins in Hong Kong, many local dried seafood retailers admit that it would not affect their business much without selling shark fins. Lee Wong-lung, one of these retailers, says that the money he earned from selling shark fins only accounts for 10 percent of his total earning.

Perhaps the traditional demand in the city is the major reason why it is hard to ban shark fins in the city. Stephanie Cheng Wing-man is going to have her wedding banquet at the end of next year. She says she would like to have a menu without shark-fin dishes because she is strongly influenced by photos and video clips online showing the cruelty of cutting off fins from sharks, but when she was choosing the menu for the banquet with her parents, they insisted that she use a menu with shark-fin dishes. “I chose the one with shark fins at the end,” she says. “They think a menu with shark fins is more decent. It was not a big deal. I didn’t want to argue with them on this.”

According to a recent survey released by non-governmental organization Bloom, almost 90 percent of a total 1,000 people interviewed attended banquets with shark fins, but nearly 80 percent of them would like to accept wedding banquets without shark-fin dishes.

According to WWF Hong Kong, there are currently 107 organizations pledging not to sell or buy shark-fin soup in any activities, and 26 restaurants and hotels provide alternative banquet menus free of shark fins.

“There is definitely a growing trend amongst environmentally-aware young couples to seek an alternative menu for their wedding banquets,” says Shane Pateman, general manager of Eaton Smart Hong Kong hotel, one of the 26. “The increasing demand of alternative choices also motivates us to provide shark fin-free menus.”

Pateman says the hotel will not stop serving shark fins because although it wishes to promote the awareness of protecting sharks, shark-fin soup is a long-time tradition in Chinese banqueting, and the hotel respects the choice of its customers. “We have limited shark-fin soup to our Chinese restaurant and Chinese banquet menus only,” says Pateman.

L’hotel Island South, on the other hand, has not provided shark-fin dishes since its grand opening last year. According to Karen Wong Ka-yan, the communication manager of the hotel, the hotel targets on young people who always follow the trend. “We support environment protection and want to set the first step. Our customers are satisfied too. There were customers who required menus with shark fins, but after we explained our idea, they changed their mind after all.”