According to the Kien Giang Hydrometeorological Station, saltwater intrusion will occur in the province from February to April 2025 at a level higher than the average of many years, with the highest salinity on Cai Lon and Cai Be rivers occurring at the end of March and April 2025. Localities in the Upper U Minh region including An Minh, An Bien, Upper U Minh, and Vinh Thuan are areas that have often been affected and damaged by drought and salinity in recent years.
Mr. Nguyen Van No, residing in Kinh Lang Dong hamlet, Dong Thai commune (An Bien) releases shrimp seeds into the pond.
According to shrimp farmers, black tiger shrimp and white-leg shrimp live and grow well in environments with salinity from 5-20‰, green crabs can tolerate salinity from 10-25‰, and suitable temperatures are from 25-32 degrees Celsius. To limit damage caused by hot weather causing high salinity, farmers in the U Minh Thuong districts proactively renovate and dredge mud in canals and square bottoms before entering the main shrimp crop of the year, thereby helping to limit organic debris that generates toxic gases when the weather is hot and the temperature increases.
Mr. Bui Van Trung, residing in Chin Xang Hamlet, Dong Hoa Commune (An Minh) said: “After harvesting the winter-spring rice crop, I dredge the mud at the bottom of the ditch to limit the accumulation of organic humus, which when exposed to hot weather creates toxic gases that affect farmed shrimp. During the farming process, I often use zeolite and probiotics to manage water quality and clean the bottom of the farming square.”
Mr. Nguyen Thanh Tung, residing in Hamlet Chin A, Thuan Hoa Commune (An Minh) said: "Before each time I supply water to the pond, I use a salinity measuring device outside the canal to avoid taking the wrong water level with too high salinity, which makes it difficult to create natural bait, making the shrimp stunted, slow to grow, and susceptible to disease". In addition, on hot days, Mr. Tung keeps the water level in the field at 60-70cm to limit the temperature difference between day and night, which is harmful to the shrimp, and at the same time, chooses good quality water to pump in.
Mr. Nguyen Thanh Tung, residing in Hamlet Chin A, Thuan Hoa Commune (An Minh) checks the salinity with a salinity meter before taking water into the shrimp pond.
For Mr. Nguyen Thanh Tuan, residing in Ba Bien B hamlet, Nam Yen commune (An Bien), on hot days when the pH in the pond increases, Mr. Tuan changes part of the water and increases the use of disinfectants to limit pathogens from entering the pond. On days of heavy rain, Mr. Tuan spreads dolomite lime into the pond about 3m from the shore to prevent the pH from decreasing, and at the same time, sprinkles minerals to increase the resistance of shrimp and crab.
To proactively prevent and combat drought and salinity to protect production, An Minh and An Bien districts have deployed new construction and reinforcement of 29 seasonal salinity-preventing earth dams to protect rice in the 2024-2025 winter-spring crop and ensure domestic water for local people.
To cope with the hot weather and high salinity during the dry season, shrimp farmers take advantage of the opportunity to fill their ponds with water when the salinity is still low. Mr. Tran Van Quan, residing in Kinh 1A Hamlet, Dong Thai Commune (An Bien) said: “To limit the high salinity affecting shrimp and crabs, I proactively fill my ponds with water when the salinity is about 5‰. During the farming process, I only add water, which also makes the salinity in the pond increase slowly compared to the actual salinity in the canals and ditches. To raise shrimp and crabs to the size of the first juvenile, I often raise black tiger shrimp in two stages until the size of about 10,000 shrimp/kg, and release the crabs into the large pond when they reach the size of the tip of the little finger.”
As for farmers in some coastal communes of An Bien and An Minh districts, green crabs are prioritized over tiger prawns and white-leg shrimp because green crabs have a high salinity tolerance and a higher selling price than shrimp, especially crabs with roe.
Article and photos: DONG HUNG
Source: https://www.baokiengiang.vn/nong-nghiep/nguoi-nuoi-tom-ung-pho-voi-han-man-24743.html
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