Can Tho’s secrets to raising healthy eels without worries of disease

The challenge of disease is always present

Eels have long been a familiar aquaculture species. They are considered a specialty of Can Tho city and many Mekong Delta provinces. Local farmers favor eel farming because it requires little capital and uses small water surfaces. Due to strong market demand, they can also earn high profits.

However, this species is highly sensitive to environmental changes and often susceptible to red spot disease, saprolegniasis, and fever. Information from Can Tho Agricultural Service Center shows that mortality rates during farming can reach 70 - 80% if water and feed management techniques are not strictly followed.

According to Quach Thi Thanh Binh, Deputy Director of Can Tho Department of Agriculture and Environment, most households raise eels in mud ponds on a small scale. They normally get seed stock and water from natural sources, which increases the risk of disease.

When weather conditions fluctuate due to prolonged heat or heavy rains, water quality drops, thus stressing the eels. Their resistance is weakened, leading to increased risks of disease. Sick eels are easy to identify. They separate from the group, raise their heads above water, lose appetite, become slimy, coil together, secrete excess mucus, develop swollen heads, and die in mass. Without timely detection and treatment, the disease spreads quickly and causes heavy losses.

Farmers need to apply effective disease prevention practices to reduce risks in the farming process, lower costs, and improve productivity. They should buy fingerlings only from certified sources. Healthy seed must have a bright color, uniform size, intact mucus, and no injuries. The recommended stocking density is 100 - 200 eels per m².

Water sources must be clean, and building settling tanks is one of the best options for eel farming. Can Tho’s professional agencies advise farmers to keep the water depth at 20–30 cm. Farmers should replace water immediately if it smells foul or turns black, and change it regularly, 1 -2 times per day. Disinfection should be done weekly with iodine or potassium permanganate. Shade covers are useful to reduce sudden environmental shocks.

Feed should be pelletized, mold-free, within shelf life, and not over-supplied to avoid water pollution. Farmers must monitor eel growth monthly to adjust feed levels, and supplement vitamins and minerals weekly to strengthen the eels’ resistance.

One thing to note is that eels grow unevenly and may cannibalize, so farmers should sort them by size every 1 - 1.5 months. Before sorting, eels should be fasted for one day to reduce stress. Tools with a smooth surface should be used instead of bare hands to avoid injury.

Mud-free farming allows eels to be safe from diseases

According to Can Tho Department of Agriculture and Environment, the city currently has over 18.4 ha of eel farms. There are nearly 1,900 eel farming households, most of which use the mud-free system with less than 200 m² of water surface. The mud-free eel farms are concentrated in Xa Phien, Vinh Vien, Nhon My, Dai Ngai, Lieu Tu, and Vi Tan wards.

Field results have confirmed how profitable the mud-free ell farming model can be. The case of Dang Thi Thu Phuong is a prime example. The eel farmer from Tan Hoa ward reports that profits reach approximately 30% on average, and can rise to 40 - 50% when prices are favorable. Every year, her family earns nearly VND 200 million in profit.

Aiming to further improve this model, Can Tho Department of Agriculture and Environment is promoting eco-friendly methods to minimize environmental impact. These include recirculating systems, water treatment technologies, and strict water management. The city also focuses on VietGAP and GlobalGAP-certified models to optimize costs, ensure quality, and boost yields and profits.

The sector is also working to establish closed value chains from seed production, feed, commercial farming, to processing and marketing. Part of the eel output is already exported to demanding markets such as Japan, South Korea, and the USA.

To further nurture the industry’s success, Can Tho needs to strictly manage production procedures and quality control. Eel-based products can be diversified into eel cutlets, dried eel, seasoned eel, and many more. The goal of sustainable eel farming in Can Tho is within sight, thereby encouraging farmers to expand the production area and output, build input zones, and increase product value.