Awakening the potential of Ben En Lake

Building a business from fish cages

In the mountainous area of Nhu Thanh (Thanh Hoa province), Ben En Lake stretches out with vast waters, deep sources, and a rich ecosystem. Drawing on this advantage, cage fish farming is gradually becoming a commercial production model, creating additional livelihoods and income for local residents.

Among those who have worked the lake for many years, Tran Xuan Thai stands out. Since 2013, he has leased water surface from Ben En National Park for aquaculture. Starting with his first fish cages, he gradually invested, built up experience, expanded his scale, and diversified the species he raises.

More than a decade on the lake has given Thai a deep understanding of water conditions, weather, seasons, and the characteristics of different fish species. Drawing on that practical experience, he took the bold step of trying new, high-value fish varieties.

By now, he and his associates have expanded to 40 fish cages. American catfish have been introduced on a trial basis at three households, including Thai's, with technical guidance, seed stock, feed support, and monitoring provided throughout the farming process. Results show that fish at all three households have grown and developed well.

According to the Nhu Thanh Agricultural Service Center, the three households participating in the model have a combined cage volume of 250 cubic meters and stocked 2,500 American catfish. The average survival rate reached 75 percent, with an average harvest weight of 1.6 kilograms per fish and a yield of 10.5 kilograms per cubic meter, exceeding the targets set.

The strong growth of the American catfish has brought satisfaction to the farmers and demonstrated the species' ability to adapt to natural conditions at Ben En. "From my actual experience raising them, I've found that American catfish adapt quite well to the lake's conditions, grow quickly, and stay healthy. With good control over seed stock, feed, and care techniques, this species holds a lot of promise," Thai said.

Opening a new direction

Building on these initial results, Thai has continued to invest in expanding his fish stock. His farming area received state support of 2,000 American catfish, delivered in two batches of 1,000 each. After more than two years of raising them, the fish now average about 2.5 kilograms each. If growth continues favorably, they could reach an average weight of more than 3 kilograms by the end of this year, ready for sale.

Beyond the supported stock, Thai is also raising about 10,000 catfish weighing around 2.5 kilograms each, along with another batch of roughly 10,000 fish stocked earlier this year that are growing well, currently weighing between 0.2 and 0.6 kilograms each. Alongside American catfish, Thai also raises spotted catfish and several other species. Diversifying the species he raises and staggering batches gives his family a relatively steady income while reducing dependence on any single product.

"I believe that for cage farming to be effective, it has to be run as a commercial operation, not on a small, piecemeal basis. Each batch of fish requires careful planning around seed stock, feed, growing time, and market outlets," Thai said.

This is also one of the model's most notable strengths. Farmers receive not just seed stock and supplies for a single crop cycle but, more importantly, access to a new way of doing things, which gives them the confidence to invest for the long term.

A report on the Nhu Thanh model found that American catfish offer several advantages, including fast weight gain, a fairly high survival rate, easy market access, high economic value, and low disease risk. At a sale price of around 70,000 to 90,000 VND (roughly USD2.70 to USD3.50) per kilogram at the time of assessment, the three participating households earned a combined profit of more than 200 million VND (roughly USD7,800) on 250 cubic meters of cage volume, about 50 to 65 percent more efficient than traditional farming methods.

Nguyen Thi Cham, Chairwoman of the Nhu Thanh Commune Farmers' Association, said the model's results carry real significance for the shift in local farmers' production methods.

According to Cham, the notable achievement is that the model has proven American catfish can grow well in Ben En's water conditions while delivering clear economic benefits. This gives residents a stronger basis for choosing new species to raise, gradually shifting from small-scale farming to commercial aquaculture.

"The model's effectiveness shows not only in yield or profit but also in building residents' confidence. Once they see a species that suits local conditions and delivers strong results, members will be willing to learn and invest. But scaling this up will require technical guidance, water quality control, zoning for farming areas, and, most importantly, linkages for product consumption," Cham said.

Nhu Thanh has numerous lakes and reservoirs with wide water surfaces and suitable depths for cage fish farming. Building on the model's results, the scale could be expanded to 100 cages, alongside stronger training, zoning of farming areas, and organizing production along commercial lines.

Even so, developing cage fish farming cannot rely on water surface advantages alone. Water quality, cage density, seed stock, feed, and care processes must all be tightly controlled. Unpredictable weather, pH fluctuations, cage sanitation, and feed management remain factors that can affect the fish stock's productivity and quality.

The story of Tran Xuan Thai and the households participating in the model reflects a shift in mindset among mountainous residents, moving from simply using the water surface to using it strategically, from small-scale farming to commercial production, and from relying solely on traditional experience to combining it with science and technology.

With continued support for seed stock, technical guidance, zoning of farming areas, product consumption linkages, and brand building, the lakes of Nhu Thanh could well become a valuable commercial aquaculture production zone, helping raise residents' incomes and awaken the untapped potential of this land.

*1$ = 26,148.50 VND (Source: Vietcombank).