Brother Tsoi, who operates fish farms in the Yim Tin Tsai (East) Fish Culture Zone, has been in the business for over 40 years. In the early days, he worked on his family’s trawler, a type of fishing boat designed to catch fish by dragging a large, cone-shaped net through the water. They sold the higher value catch while passing the remaining “trash fish” on to fish farmers to use as feed. These so-called “trash fish” consisted mainly of small species such as scaled sardines, rabbitfish, ponyfish, small yellow croakers, shads, and other mixed catch too small to be sold in wet markets. A fishing vessel could haul in several hundred catties of such fish each day, yet typically only about two-thirds could be sold, with the rest discarded back into the sea.

As the volume of trash fish increased, Brother Tsoi began to reconsider his business model: with such an abundant supply of trash fish, and others around him starting up fish farms, he figured, why not try it himself? He realized that using unsold catch as feed could significantly reduce his costs and increase his profits. So, in the 1980s, he set up his own fish rafts. 

In earlier years, fishermen could apply for marine fish culture licences from the AFCD, but after 1990, no new licences were issued. Those who wanted to expand their businesses could only acquire licenses from existing operators. As Brother Choi explained, it takes about a year for farmed fish to grow large enough to sell, so to maintain a steady cash flow, one fish farm needs to have ten or twenty rafts going at the same time to produce a steady monthly supply. 

How are traditional fish rafts built?

A typical fish raft consists of a sturdy timber frame held above water on floats. The wooden beams are arranged in a criss-cross pattern like a tic-tac-toe grid, and beneath each square a net known among fisherfolk as a fish cage is hung.  

According to fishermen in the Yim Tin Tsai (East) Fish Culture Zone, a traditional fish cage is typically about 10 feet wide and 8 feet deep. Each raft usually contains around 9 to 12 cages, with each cage containing approximately 400 to 500 fish. 

The construction of a fish raft usually begins on shore. Fisherfolk first bring the timber, floats, and tools onto the beach, where they set up a simple work platform. The wooden structure is assembled on this platform, and as construction progresses, it is gradually pushed into the water where it will serve its eventual purpose. Once the first raft is completed, subsequent assembly becomes much easier, as the layout and structural framework are already in place. Additional sections can simply be attached to the sides to expand it, and much of the work can take place on the water by tying the materials together and towing them into position with small boats. 

Capture and culture

Most early fish raft operators started out catching wild fish, which led to a hybrid model merging fishing with aquaculture. The fishermen still went out to sea and sold the larger, higher-value fish at wholesale markets, while putting the smaller fish into fish cages to mature to a marketable size. 

At that time, most fish fry were wild-caught. Fishermen worked in pairs; one stayed onshore holding one end of a net, while the other piloted a small boat to encircle schools of juvenile fish. Afterwards, the fry were moved into the fish cages to grow. In the past, local species like threadfin, red grouper, and rabbitfish were frequently farmed on fish rafts.

Net-cage aquaculture provided multiple benefits: it enabled controlled feeding and more consistent growth, allowing farmers to raise fish to market-preferred sizes. Over time, fishermen came to see that farmed fish could be more profitable than wild-caught fish alone, and so more of them entered the industry.

By the 1990s, nearshore fish stocks had been depleted, making it more difficult to depend on wild-caught fry and feed. Meanwhile, diners became more selective and consumer tastes turned towards more expensive groupers. In response, farmers started importing fry mainly from mainland China and Taiwan and shifted toward farming more valuable species such as red, green, and spotted grouper. Farmers also raised larger species such as giant grouper for banquets, letting them grow to over 2 catties (1.2 kg) before sale. 

For the purposes of production and marketing, fish are sorted into two categories based on their growth rate and size. Fish weighing over two catties are classified as “banquet fish” while those weighing around one catty or slightly less are sold as “wet market fish” for household consumption. As Brother Choi explains, fish in the same batch grow at different speeds. Faster-growing fish may be kept longer and raised to banquet size to fetch higher prices. Slower-growing fish are sold as soon as they reach about one catty because keeping them longer would waste time and feed, and households do not normally buy larger fish anyway.

There are two major channels for fish sales: some farmers establish long-term relationships with seafood stalls and supply them directly, while others sell through wholesale channels. Under the Marine Fish (Marketing) Ordinance, wholesale markets operated by the Fish Marketing Organization only accept fresh marine fish, not live ones. Here, “fresh” means chilled dead fish, while “live” means they are still alive at the point of sale to the consumer. Live fish trading does not usually take place inside the Fish Marketing Organization’s wholesale markets, but at informal wholesale points just outside, such as at Aberdeen, called “lan tau” in Cantonese. Buyers purchase fish directly from fishermen before distributing them to wet markets or restaurants. This has created two parallel systems, one for chilled fish operating through the formal wholesale market system, and another for live fish circulating through informal trading networks, each operating according to its own methods. 

The difficulties

In recent years, marine fish farms have faced numerous pressures that threaten their survival. The first challenge comes from increased competition from imports. Whether chilled or live, fish flown in by air have become increasingly price-competitive as the supply has grown and transport costs have fallen. Large quantities from mainland China, Taiwan and Southeast Asia now flood the Hong Kong market, making it difficult for local producers to compete on price. 

More importantly, imports can provide a stable and continuous supply. Large restaurants and supermarket chains can establish long-term contracts directly with overseas suppliers, guaranteeing daily deliveries. In contrast, local fish farms can only produce in limited batches, often harvesting just once a month, which makes it challenging to fulfill the regular demands of large clients. This limitation puts them at a disadvantage in price negotiations. 

Another challenge comes from changes in the natural environment. Global warming has raised sea temperatures and made the climate more unstable. This results in stronger typhoons capable of destroying fish rafts in an instant. Additionally, red tides have become more common in Hong Kong’s fish culture zones. These happen when water becomes eutrophic due to elevated levels of nutrients such as nitrogen and phosphorus that encourage the rapid growth of algae and plankton. As these organisms proliferate, they deplete the oxygen levels in the water, suffocating the fish. Worse, some types of algae also produce toxins poisonous to fish. 

Red tides have complex causes. Aside from pollution, they are also associated with rising sea temperatures, poor water circulation, and prolonged cloud cover. Historically, fishermen depended solely on experience and luck, but now, monitoring tools can provide early alerts so that they can tow their rafts away in advance. Yet large red tides still pose significant challenges. In 1991, a severe red tide in Tolo Harbour killed over 90 percent of the local fish, resulting in severe losses for many fish fisherfolk. 

The industry is also experiencing a succession crisis. Most fish raft operators today are older former fishermen. Their children, raised in the city and having received modern educations, show little interest in this traditional industry, which requires long hours exposed to the elements and brings in an unstable income. As Brother Choi put it, “It’s hard to pass this on from one generation to the next. They don’t have the foundation, and working in finance or an office is more appealing than standing out here in the sun.”

The industry is also experiencing a succession crisis. Most fish raft operators today are older former fishermen. Their children, raised in the city and having received modern educations, show little interest in this traditional industry, which requires long hours exposed to the elements and brings in an unstable income. As Brother Choi put it, “It’s hard to pass this on from one generation to the next. They don’t have the foundation, and working in finance or an office is more appealing than standing out here in the sun.”

Finding a way forward

The government started easing regulations in the early 2000s, allowing fish farmers to convert their businesses to recreational fishing with certain conditions. Operators have to obtain consent from nearby fish raft owners, make substantial alterations to their facilities, and pass safety inspections before opening their rafts to the public for paid fishing. In recent years, the AFCD has also launched a scheme called “Fish enJoy”, which allows fishermen to cook and sell their catch on fish rafts using non-flame cooking methods.

For a while, this offered fishermen a new source of income and gave urban residents a chance to enjoy fishing on the water. But after the pandemic, as more and more people travelled to the mainland for leisure, recreational fisheries there developed rapidly. Some now offer all-in-one packages including boat hire, fishing gear, meals, and accommodation at prices that are hard to beat, putting Hong Kong’s recreational fishing businesses under heavy pressure.

In response, some fish farmers have been looking for other ways forward. A number of fishermen have partnered with universities to turn their fish rafts into research sites for experiments with new species. This includes setting up nursery areas on the rafts for fish fry, adjusting water salinity, isolating fry affected by disease or pests, and learning how to treat sick fish under the guidance of veterinary specialists. Brother Choi has also recently started experimenting with farming shellfish, using their natural filtering abilities to improve water quality and generate another source of income. 

On the other hand, the government has been promoting a more technology-driven path for the industry. Pilot deep-sea cage farming projects have been launched at Tung Lung Chau, alongside the introduction of underwater robots, automatic feeders, and water-quality monitoring systems. If these technologies become more widely adopted, they could help improve productivity and resilience in Hong Kong’s aquaculture sector, opening up new possibilities for traditional fish rafts.

Although fish farming has become more difficult, some like Brother Choi hang on, looking for ways to continue this most distinctive of Hong Kong industries. 

Yet as the old gives way to the new, as the industry transforms, and the generations turn over, the meaning of “fish raft” is quietly evolving. On the one hand, there is a gradual move towards modern deep sea fish farming, and on the other, the wooden fish rafts that dotted the sheltered bays, and the labour and lives built around them, are gradually fading away. 

This article was written by contract researcher Ng Cheuk Hang.

Special thanks to Brother Choi, fish farmer at Yim Tin Tsai, Tai Po.