Solutions for contaminated shrimp farming areas

Quang Tri Province has nearly 300 hectares of low-tide agricultural land concentrated in Trieu Phong, Gio Linh and Vinh Linh districts. So far, mainly shrimp have been farmed on these areas. However, due to spontaneous development, not according to plan, not strictly according to the technical process of this kind, it has caused environmental pollution and frequent epidemics. The ponds are located in low-lying areas, so it is difficult to improve the pond bottom. In addition to the frequent exchange of water by tidal currents, the risk of possible diseases in the pond itself is very high.

In order to restore some inefficient shrimp farming areas, diversify farming species, and increase economic efficiency per unit area in a safe and sustainable manner, Quang Tri Agricultural Extension Center will introduce a pond fish farming model in 2022. The model was implemented on an area of ​​4,000 m2 with 8,000 juveniles and a stocking density of 2 fish/m2 in Nam Son Village, Trung Giang Municipality, Gio Linh District. Model of the use of industrial feed with a high protein content. Households participating in the scheme are supported by the provincial Agricultural Advisory Center with 50% of the cost of buying seeds and feed.

Mr. Tran Van Thuong from Nam Son Village, Trung Giang Township, the owner of the model, said that in the past, due to the spontaneous development of shrimp farming in cultural areas at low tide, he did not master the technique, so the farming process often occurred. Some ponds for raising him had to be abandoned, which brought no economic benefit. When he heard that the provincial Agricultural Advisory Center had introduced a model for raising butterflies in ponds on inefficient shrimp farming land, he boldly signed up to take part. With the support of the provincial Agricultural Advisory Center, Mr. Thuong boldly converted 0.4 ha of inefficient shrimp farming in low-water farming areas to build a commercial Cobia model.

Fisheries Technical Officer of Gio Linh District Agricultural Extension Station Engineer Hoang Kim Khanh said: In order to achieve high economic efficiency, the pond fish farming model requires farmers to strictly follow the process techniques such as: Pay attention to investment in well-maintained Ponds and lagoons, solid dykes, water level maintenance in the ponds according to technical requirements, seeds must be obtained from reputable companies.

During the rearing process, it is necessary to strictly manage the pond environment and the amount of food for the fish, and to regularly monitor the weather changes in order to have an effective maintenance plan. Weekly measurement of environmental factors such as pH, alkalinity, salinity… to ensure parameters are within appropriate thresholds. Lime is used regularly every 10 days at a dose of 3 kg/100 m² to prevent fish diseases; On the one hand, regularly check the activities of the fish reared in the pond in order to take timely measures, on the other hand, also check the growth rate in order to adjust the amount of feed accordingly.

Profit 160 million VND/ha/crop, low risk

Fish farming uses high-protein industrial feed, so the water environment is prone to pollution, and drought will cause water loss in the pond, so farmers need to change the water regularly. The water level in the pond is always kept above 1.5 m. In order to provide oxygen for the growth and development of fish, it is necessary to regularly use pond aeration systems. In the last days of July and August, the inflowing water has salinity >25 ‰, it is necessary to actively acquire fresh water to pump into the pond to reduce the salinity and provide a suitable and stable living environment for fish create. In addition, it is necessary to use minerals and microbiological products Emuniv-TSI to hit the pond to clean the water source and the environment for the pond.

At present, after nearly 5 months of implementation, the pond fish farming model shows that the farmed fish are growing rapidly, the average size is 4 fish/kg, the survival rate is 85%, and exceeding the set target. With a selling price of VND160,000/kg, the model is expected to achieve a net profit of over VND64 million/0.4ha/crop after 5 months of farming, which is more than VND160 million/ha/crop.

Mr. Tran Van Thuong, the farm household owner, said that the previous inefficient form of redfish farming in shrimp ponds not only brought economic value, but also had a very positive impact on the pond environment and maintained the stability of the farming area. Next time, he said, he’ll continue to replicate the model with a few more ponds.

According to Mr. Thuong, compared to shrimp farming, the profit of scorpion fish is not the same, but the risk is small, the investment is smaller, the disease is smaller, the breeding environment is more suitable and stable. Rearing with a combination of natural feed can reduce the amount of industrial feed and farm costs. The cultivation process is limited to the use of antibiotics and environmental treatment chemicals, only microbial products are used, so the quality of meat and fish is delicious and the price is always guaranteed at a high level.

Mr. Nguyen Xuan Cam, Vice Chairman of the Trung Giang Township People’s Committee, appreciated the model very much. The implementation of the Quang Tri Agricultural Advisory Center model has helped transmit the technology of butterfly farming to the people of the community. The model will create a premise to add new agricultural species, alternate and mix with shrimp and crab species to limit environmental degradation and disease. The model shows that the carp is fertile, grows well, is suitable for the local climate and weather, and has high economic value.

Mr. Phan Van Phuong, deputy director of Quang Tri Province Agricultural Advisory Center, said that the model of diatom farming in ponds converted from shrimp ponds is inefficient in cultural areas at low tide, showing that this cultural object change is appropriate. not only bring stable economy, low risk, but also reduce the environmental impact in ponds.

In the coming period, the Agricultural Advisory Center will continue to replicate this model, as well as introduce more new types of farming and new farming methods to restore some inefficient shrimp farming areas and diversify the species in a safe and sustainable direction. This is a farming model, which is very suitable for low-water farming areas, where diseases are common, and contributes to environmental protection…