Hoa Xuan Commune authorities said on November 10 that they were working with relevant agencies and residents to determine why large numbers of fish and lobsters had suddenly died in floating cages in Vung Ro Bay.
The deaths began on November 9, affecting mainly lobsters, pomfret, cobia, red snapper and grouper. Large numbers of dead and distressed fish floated to the surface, prompting farmers to collect, dispose of or sell them to traders.
Dang Thi Tham, a farmer in Vung Ro Village, said she had raised more than 15,000 brackish-water fish in several cages since early 2026, with harvesting due to begin in just over a month.
However, fish began showing signs of distress and oxygen deprivation on the morning of November 9, forcing her to sell those still alive at heavily discounted prices.
She estimated her losses at around VND 200 million (USD 7,660).
Other farmers in the bay, particularly those operating cages close to shore, reported similar losses.
By the morning of November 10, many had rushed to sell their remaining fish to traders amid fears of further deaths.
Tran Thi Bich Dan, a local fish trader, said she had purchased about five tonnes of distressed fish from 10 floating farms on November 9.
Prices had fallen sharply, with cobia normally selling for VND 150,000 per kilogramme fetching just VND 70,000-80,000 when affected.
Farmers were also forced to discard several tonnes of dead fish that traders refused to buy.
Inspections on November 10 found that around 20 floating farms had been affected, with nearly five tonnes of fish and lobsters reported dead.
Residents suspected that heavy rain had sent large volumes of freshwater into the bay, reducing oxygen levels and causing freshwater shock among farmed fish and lobsters. The cause has not yet been confirmed.
Local officials advised farmers to monitor weather conditions and lower their cages or move them further offshore to reduce exposure to sudden freshwater inflows.
According to Dak Lak authorities, eastern parts of the province received 20-50 millimetres of rain between 8am on November 9 and 8am on November 10.
Water levels were rising on the Co River at Da Loc Station and the Ban Thach River at Hoa My Tay Station.
Heavy rain and thunderstorms were forecast for eastern Dak Lak from November 10 to 12, with rainfall generally reaching 100-200 millimetres and exceeding 250 millimetres in some areas.
River and stream levels were expected to rise rapidly, increasing the risk of flash floods and landslides in mountainous areas and localised flooding in low-lying riverside communities.
Areas at risk included Xuan Lanh, Phu Mo, Tuy An Bac, Dong Xuan, Hoa My, Hoa Thinh and Tay Hoa communes, along with Dong Hoa and Phu Yen wards.
