Take a stroll down Des Voeux Road West in Sheung Wan, and you’ll find yourself inhaling a distinct, salty whiff of dried seafood that fills the air as trams rattle past in the old Hong Kong neighbourhood. Walk into a store and you’ll see thick pieces of dried swim bladders casually hanging off a rod or stacked up on display on counters. Local caterers say the bladders come in all shapes and sizes – usually croaker, cod and basa species and sometimes totoaba a threatened species generally found in Mexican waters. The Mexican government has banned trading in totoaba since 1975, but illegal poaching persists. To get a better sense of what was happening in the city, members of the conservation group Greenpeace visited 70 local dried seafood stores between February and April in 2015. They found that 13 were still selling bladders of the endangered species. “People tend to have an appetite for totoaba’s bladders because of their resemblance to Chinese bahaba, a species of croaker that is often referred to as the yellow-lipped fish,” says Greenpeace’s Bonnie Tang Man-lam. “However since bahaba have become critically endangered, sellers and wholesalers have turned to totoaba because the maw is quite similar in appearance.” According to WWF, the global conservation body, 3,272 tonnes of fish maw was imported to the city last year, with a total value of about HK$2 billion (US$254.87 million). For years, such bladders have been used to make soup that is believed to be a good source of collagen, which nutritionists say can cure joint pain, among other ailments. The dried goods are also especially popular among expectant mothers to help ease some of the discomfort of pregnancy. Despite the varieties, totoaba bladders remain one of the most highly prized fish maws on the market and are perceived to be of superior quality. It is believed they can fetch up to HK$1 million per kilogram. Other species sell for about HK$200,000 per kilogram on average. The iconic Chinese animals heading for extinction But high demand for this type of fish bladder does not threaten to wipe out just one species – it’s driving an endangered porpoise into extinction too. “The fish isn’t the only victim,” says WWF-Hong Kong’s Tracy Tsang Chui-chi, whose work focuses on sustainable oceans. Fishermen set large vertical nets to catch the totoaba by their gills, Tsang explains, but the fishing nets also trap vaquita, a rare marine mammal that lives in the same area, of which fewer than 57 are left in the world. Are you eating threatened species of fish? Here are the 17 to avoid in Hong Kong In fact, international trading of totoaba is banned, and Hong Kong officials are taking action to address illegal activities. Earlier this year, the Customs and Excise Department seized about 28kg of suspected totoaba macdonaildi fish maws. Its estimated market value was about HK$4.5 million. We must start dining in a way that will care for our ocean Bonnie Tang, Greenpeace Two men, aged 30 and 32, were arrested in the case at Hong Kong International Airport after travelling from Hermosillo to Monterrey in Mexico, and onward via Seoul, South Korea. Many seafood retailers take pride in offering such delicacies, but WWF-Hong Kong is calling on local officials to take stronger action against illegal fish maw trading. As boycotts against shark fin gain ever greater traction, some green groups worry that restaurants which host Chinese banquets will resort to fish maw as a substitute. Tang says while there is no evidence fish maw consumption is on the rise, Greenpeace is concerned that “catering venues are replacing shark fin with fish maw without carefully studying the origin of the dried goods”. “We must start dining in a way that will care for our ocean,” she says. Tang believes consumers also bear a responsibility to find out the origin of the maw they consume before buying it. Yet not all hope is lost. Last week, some 60 people set aside time from their busy schedules to take part in a non-profit event stressing the importance of sea conservation. Called Conservation Day at the Beach, the clean-up was organised by Treasure Island, an outdoor education and recreation centre, in coordination with the Mexican consulate and the local Mexican Chamber of Commerce. The initiative was supported by WWF-Hong Kong. Participants at the event, held at Pui O on Lantau Island, sought to raise awareness of sustainable fishing and advocate biodiversity protection. Eating fish sustainably: how Hong Kong is decimating fish stocks with its appetite Mexican consul general Damián Martínez Tagüeña says the protection of marine ecosystems requires “effective global action”. “This can only be achieved through closer dialogue and cooperation between governments, businesses, NGOs and individuals.” The group also helped paint a large mural on the beach with a design by Mexican artist Jaime Ruiz Martínez. It highlights their efforts to save the totoaba and vaquita. What is fish maw? Fish maw is the dried bladder of large fish. It is commonly used in highly prized traditional Cantonese meals, especially as a soup ingredient. It is believed to contain high nutritional value and is particularly popular with women because it is a good source of collagen, which can improve skin texture and preserve good complexion. It is also rich in phosphorus and calcium. In traditional Chinese medicine , fish maw soup is believed to nourish yin – which is responsible for moistening and cooling bodily functions – to help achieve a balance between yin and yang . Due to its high value and limited supply, fish maw is often imitated. Bogus versions use squid, fish skin or fin soaked in hydrogen peroxide and sulphur. Some suppliers even use pig’s skin or plastic to create fish maw. When uncooked, fish maw is a golden yellow colour whose scent is redolent of seawater. Before cooking, dried fish maw must be soaked until it is softened. In recent years, amid growing outcry over serving shark’s fin soup during traditional Chinese banquets, many restaurants have replaced the expensive delicacy with luxurious fish maw soup or bird’s nest soup.