According to the Department of Agriculture and Environment of Quang Ninh province, after receiving information about the situation of sea fish raised in the Cap Tien village farming area, Van Don Special Zone dying (parallel fish, pigs), in October, the Department of Fisheries, archipelago and Fisheries, and the Fisheries Control coordinated with the Northern Center for Environmental Monitoring and Seafood Diseases to collect samples in this farming area.
Through analysis of samples collected at the scene, it was found that the parameters: Temperature, pH, DO, salinity, COD, N-NO2-, H2S, P-PO4 3-, TSS, iron all have values within the permitted limit. No toxic algae were detected in the analyzed samples.
However, the alkalinity and N-NH4+ at some monitoring points have inappropriate values (alkaline values are lower than the permitted threshold). Low salinity (20‰), clear evidence that the farming area has experienced a large-scale thinning phenomenon due to fresh water after storms. These are "signs" that show that the underlying environment has suddenly degraded due to recent floods, which are unfavorable conditions that weaken the health and resilience of farmed fish.
To promptly implement measures to overcome environmental changes and prevent disease-causing agents for farmed aquatic animals, competent authorities recommend that localities with seas, enterprises, cooperatives, and aquaculture facilities comply with the seasonal schedule for release of breeds and selection of aquatic species at facilities granted by competent authorities to qualify for production and breeding, carry out nation quarantine according to regulations, and store invoices and documents as a basis for traceability.
Limit the use of solid fish food as food to avoid cross-infection with infectious diseases; add vitamins and minerals to the diet to increase fish resistance during the transitional season.
Proactively manage environmental factors during the changing seasons, when the weather is harsh and sunny with heavy rain; apply comprehensive management measures to maintain stable water quality, regularly monitor and observe farmed cages to take timely measures.
