What Will Save Hong Kong’s 700-Year-Old Oyster Farms?

Lying to the northwest of Hong Kong, Deep Bay is a shallow U-shaped inlet surrounded by wetlands. Fresh water empties into the bay, merging with sea water to form a brackish seabed perfect for coastal oyster farming. The industry has been here for 700 years, first brought by fishing people from nearby Shajing, in present-day Shenzhen. At the center of this bustling trade sits Lau Fau Shan, a settlement famous for its golden oysters. But all is not well. 

It’s mid April and labourers whistle and yell for lollygaggers to move along as they coax sloshing barrels of live seafood through the lanes of Lau Fau Shan. Inside a nearby building, the Deep Bay Oyster Cultivation Association, there is a commotion. Chan Shu-fung, the association’s young chairman, pokes his head out the door. In a flamboyant floral t-shirt, Chan is all smiles and courtesy but he is in the midst of a crisis. “They’re all dead. All dead,” he exclaims between frenzied phone calls. “Look, I’m dealing with a lot right now.” A red tide, first spotted at the end of March, has wiped out Lau Fau Shan’s stock of oysters. Years of work – obliterated. 

With his phone buzzing anew, the harried chairman returns to his disaster, leaving us with an oyster farmer, Chan Wai-cheong. Chan ferries us to one of his 60-odd bamboo rafts bobbing listlessly out in Deep Bay. Boarding the raft, he squats and hoists a dripping rope out of the murk. Raising it high he shows what remains of his oysters: empty mud caked shells. The algal bloom has made short work of the animals that once lived inside. 

Thousands of oyster rafts dot the waters of Deep Bay. Photo by Billy Potts

Chan, who was born in Shajing, pootles along amongst rafts where farmers with little else to do make repairs and contemplate a lean season. “It’s unlikely my children will join the oyster business,” he says, hands on helm and eyes fixed ahead. “What if the harvest is suddenly wiped out again? How would they live?” Chan, who shucked oysters as a child, has worked the trade all his life. “At that time oysters were fat. But this isn’t the case anymore.” 

Fully grown, Lau Fau Shan’s golden oysters can reach 10 centimetres in length. But overcrowding in the bay has put immense pressure on the ecosystem and now oysters seldom reach their full size. With mainland factories moving away from the Pearl River Delta and Hong Kong closing many of its pig farms, water quality has generally improved over the past decade. Yet Deep Bay’s oyster farmers are still at fortune’s mercy and competition is fierce. There are only around 10 Hong Kong oyster farming families and this cannot account for the 11,000 strong flotilla of rafts that can be seen stretching towards the horizon. Citing pollution, Shenzhen’s government banned oyster farming from their side in the 2000s – many of the rafts are likely owned by mainland oyster farmers desperate enough to farm illicitly. All together, this has pushed the bay to its ecological brink. 

Three million people live near the shores of Deep Bay – about half a million in Yuen Long and the rest in the Shenzhen districts of Nanshan and Futian. That large population feeds the bay’s water with waste, which in turn provides the nutrients needed for algae growth. “For many years it’s been impossible to culture oysters back in Shajing because of rapid development,” says Chan of his hometown. “Lau Fau Shan is a protected area, you can’t develop here so we can farm, but we must still share the water of the bay.” On top of all this, the industry is now beset by labour shortages since the pandemic has halted the flow of mainland farmers which Hong Kong’s oyster industry relies on. “The outlook isn’t good,” says Chan.

Oyster farming in Deep Bay is done using the off-bottom system, in which oysters grow on rafts, which is widely considered to be one of the most productive methods of farming. But it hasn’t always been this way. “This method of hanging oysters is a modern one. We learned it from the Japanese. We Chinese have only known about it for 40 odd years. Maybe 50,” says Cheong Sou—Auntie Cheong—the matriarch at Chan Cheong Kee, a renowned family-run oyster sauce concern with origins in the Song Dynasty and “more generations than can be calculated.”  

Auntie Cheong atop discarded oyster shells. Photo courtesy Liquid Stories

A ten-minute drive northeast from Lau Fau Shan’s main drag, Chan Cheong Kee has escaped the worst of the red tide. It’s hard to say for certain but it is supposed that Chan Cheong Kee’s oysters were spared in part because some of them had been growing in the intertidal zone, rather than out in the middle of Deep Bay. There is no guarantee that they will always be so lucky. 

Auntie Cheong, now 73, is weather-beaten but strong from a lifetime of work. Easily hefting a mud scooter (waat6 baan2 滑板) over her shoulder, she lugs it down to a muddy bank that sucks at her Wellington boots. Mounting the board, the septuagenarian propels herself with the grace of a figure skater. This is how she and her family survey their oyster fields. Alighting from the board, Auntie Cheong crouches by a mountain of shells. Oyster pick in hand, she explains how the bivalves were once widely cultivated using an intertidal system, a system which Chan Cheong Kee still uses alongside its rafts.

Auntie Cheong explains. “On the 28th day of the fourth lunar month, we cultivate new oysters by placing old shells in the mud at low tide,” she says. “You line them up in rows with the heavy side down so they won’t get knocked over by waves. After about two weeks you wade into the water and feel whether oyster larvae have attached to the old shells.” The summer months are worrisome for any oyster farmer – a yellowing of the sky and the sight of ominous clouds billowing in the west are bad news. “In the old days, we didn’t have a weather report but when you saw that, you knew a typhoon would land within the hour bringing waves that could flip a boat. That happened twice. I held a son and a daughter under each arm, and prayed to Tin Hau.” A direct hit could mean the end of an entire oyster crop.

Every oyster from planting to harvest takes five years, during which time there is a complicated system of moving them in the sixth and 10th lunar months so that they don’t suffocate in the mud. In the fifth lunar month of the fourth year on the mudflat, oysters are transferred to rafts in deep water where they can grow out. This new practice relieves the oyster farmers of much hard labour. “Doing this, there is no need to go into the water to harvest them in winter,” says Auntie Cheong. “In the old days it didn’t matter how cold it was – if it was extremely cold you’d have to pick the oysters out using a pair of prongs. It used to be so cold that my joints went ‘boolook boolook boolook.’ Young people today wouldn’t suffer like that.” 

By the eighth to 10th lunar months of their fifth years, the golden oysters are mature and ready to be harvested for drying. “That’s my favourite time,” says Auntie Cheong. “After Chung Yeung Festival [in mid-October] the wind shifts and the time for typhoons passes. We can relax a bit.” 

Oyster rafts with Tin Shui Wai in the background. Photo courtesy of Liquid stories

With Lau Fau Shan’s centuries old mariculture tradition and the community which surrounds it in danger, oyster farmers are turning to modern solutions in a bid to rehabilitate Deep Bay’s unique marine ecosystem. For one of these solutions, oysters themselves may be the key. Working with The Nature Conservancy, a global environmental organisation, farmers are participating in a bay-scale carrying capacity research, to better understand the effects of oyster farm overloading. This will help estimate how many farms can sustainably operate in Deep Bay. The farmers are also supplying spent oyster shells from Lau Fau Shan to help restore shellfish reefs in parts of Hong Kong where oysters have been lost, which are bleached in the sun and gathered into biodegradable mesh bags. Launched from a fish farm in the serene waters of Three Fathoms Cove in Tolo Harbour, one such reef has already been trialled with promising results. 

The idea behind oyster shell reefs is to attract oyster larvae and other filter feeders which naturally build on such material and clean water of excess nutrients that would otherwise cause algal blooms. Gazing into the waters of the cove, The Nature Conservancy’s Marine Thomas details the findings from the experiment. “The results that we got after deploying the structure, which was all recycled shell, were phenomenal,” she says. “After three months the reef was full. Full of crabs, fish, full of baby bivalves, baby sea urchins, lots of babies. It gave us a lot of hope.” The team, which regularly measures oxygen levels in the water, has witnessed marked change but perhaps most encouraging of all, sea turtles—long absent—have returned to the area. 

Though the pilot project has concluded for now, The Nature Conservancy’s oyster reef restoration efforts could one day become an alternative source of income for Deep Bay’s oyster farmers It would be an invaluable step towards a healthier relationship between the city and the sea that gave it birth. This could signal a chance to save a colourful ecosystem and maritime culture for generations to come. There is a long journey ahead for Deep Bay and its inhabitants on both sides, but it is one that is certainly worth taking.

This article was written in conjunction with Liquid Stories, a project by Valerie Portefaix and Caroline Ha Thuc on Hong Kong’s coastal cultures and cuisine, which will go on show at the Art Museum of Guangzhou Academy of Fine Arts from 27 September 2021.

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