Analysis of water samples from the river area where 50 tons of sea bass died in Thach Son commune (Thach Ha district, Ha Tinh province ) revealed that four parameters were unsuitable for fish farming.
Sea bass belonging to residents of Song Hai village, Thach Son commune, died on October 6th.
On October 6th, in the fish farming area on the Nghèn River, below the Đò Điểm wharf, belonging to residents of Sông Tiến village, Thạch Sơn commune, Thạch Hà district, a mass fish kill occurred, resulting in the death of 50 tons of sea bass.
Upon receiving the information, the Fisheries Sub-Department dispatched officers to collect three water samples from the aquaculture area and sent them to the Northern Center for Environmental Monitoring and Aquatic Animal Diseases (Research Institute for Aquaculture I) for testing.
The results of the water sample analysis show that, basically, all indicators in the three analyzed water samples are within the permissible limits according to QCVN 10:2023/BTNMT (National technical standard on seawater quality), QCVN 08:2023/BTNMT (National technical standard on surface water quality), and QCVN 02-19:2014/BNNPTNT (National technical standard on aquaculture conditions).
Fisheries officials are taking water samples from the area where the fish died.
However, there are four parameters whose values are unsuitable for fish farming: pH, salinity, alkalinity, and total iron.
Specifically, at the 3 monitoring sampling points, salinity was low; alkalinity was 1.11 times lower than the permissible limit (60 – 80) according to QCVN 02-19:2014/BNNPTNT; and total iron content was higher than the permissible limit (
According to recommendations from the Northern Center for Environmental Monitoring and Aquatic Animal Diseases, low salinity, low alkalinity, and high total iron content are unsuitable conditions for fish growth and development.
High iron content can hinder the respiration of fish and cause toxicity, especially in young fish. Low pH levels can increase the toxicity of heavy metals.
Low pH levels can increase the toxicity of heavy metals.
To address the fish kill and stabilize production, the Fisheries Sub-Department requested the Thach Ha District People's Committee to direct the Thach Son Commune People's Committee and aquaculture households to continue implementing measures to ensure production: inspect and treat water environmental factors where cages are located, ensuring that environmental factors are within permissible limits; move cages to areas with suitable water quality (if necessary); increase resistance, regularly monitor the health of farmed aquatic animals to take timely remedial measures, and clean, dry, and disinfect cages.
Temporarily suspend all fish farming activities at this time and monitor regularly. If any unusual signs are detected in the river or aquaculture area, report them to the authorities for timely action.
Van Duc
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