Around 13 tons of farm fish on Lake Batur died this week after extreme weather over the weekend reportedly triggered sulfur upwelling from the lake bottom.
The incident has been confirmed by officials from Bangli regency, who said that 22 fish breeders have reported losses so far.
I Wayan Sarma, who heads the Agriculture, Food Security, and Fisheries Agency in Bangli, told local media outlets that the fish kill was noticed when the lake water started changing color on Sunday, following days of heavy rain and strong winds around the lake.
Wayan said the weather triggered sulfur upwelling, leading to a drastic change in oxygen levels which eventually killed the fish.
According to the official, sulfur upwelling is not uncommon in Lake Batur, though it did not occur last year. He said fish breeders might have taken a chance this year despite having seen upwelling in the years prior.
The water in Lake Batur has returned to normal since, but authorities are cautioning fish breeders to anticipate the possibility of more upwelling in the near future.
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