JAKARTA (ANN/THE JAKARTA POST) – The Ministry of Maritime Affairs and Fisheries has initiated an inquiry into a mass carnage that affected thousands of fish at floating fish farms located at the Jatiluhur Dam in Purwakarta Regency, West Java, during the weekend.
Representatives from the ministry’s Directorate General of Fish Farming, accompanied by staff from the Purwakarta Animal Husbandry and Fisheries Agency, went to the dam on Monday to gather water samples for testing.
Ujang Komarudin, the Director of Freshwater Fish Farming, believed that around 100 tonnes of fish perished in the event, with goldfish making up the majority.
“Given that the price of goldfish is around IDR22,000 (USD1.34) per kilogram, this mass die-off has led to an estimated loss of around IDR2.2 billion for the fish farmers,” he said on Monday, as reported by Antara.
While the cause of the event remains under investigation, Ujang proposed that the large-scale fish mortality was probably due to severe weather conditions and a natural occurrence referred to as upwelling – which takes place when wind causes deeper waters to mix with those at the surface, resulting in oxygen depletion for fish that inhabit the upper surface, as deeper waters generally possess lower oxygen levels.
Last week, fish farmers at the Jatiluhur Dam noted several days of intense rain and powerful winds in the region, which also led to a decrease in water temperature, worsening the situation.
Intan Riyani, head of the Farming Department at the Purwakarta Animal Husbandry and Fisheries Agency, stated that the upwelling phenomenon happens often at the Jatiluhur Dam, especially in the rainy season.
“Overfishing has further increased the risk of mass fish deaths at the Jatiluhur Dam, as fish feed contributes to pollution in the lake, which has deteriorated the water quality in the reservoir,” Intan said, as reported by Tribunnews.
She observed that there are presently about 44,000 floating fish farms at the Jatiluhur Dam, significantly exceeding the optimal number of 11,300 units. Her agency is proactively striving to decrease the quantity of fish farms in the reservoir.
Intan also mentioned that the ministry has been alerting farmers since November of last year, recommending that they collect their fish ahead of time. Nonetheless, numerous farmers chose to let their fish grow bigger instead.
Following last week’s massive fish die-off, the Maritime Affairs and Fisheries Ministry has called farmers at the Jatiluhur Dam to gather all their fish, especially goldfish, since they are very sensitive to fluctuations in dissolved oxygen levels.
The ministry has recommended farmers to pause fish farming activities for the time being until the weather conditions improve and water quality stabilizes. Moreover, officials have encouraged farmers to gather all of the deceased fish and dispose of them appropriately to avoid contamination and pollution of the reservoir.
Earlier this month, Severe weather and high winds resulted in the deaths of thousands of tilapia in fish ponds at Ngebel Lake, Ponorogo Regency and East Java – causing millions of losses in rupiah.
Last month, severe weather caused upwelling in floating fish farms at Maninjau Lake, Agam Regency, leading to the death of approximately 25 tonnes of tilapia and losses amounting to IDR625 million.
