More than 500 tons of freshwater fish including milk fish and tilapia have drowned in commercial fish cages in Talisay, Batangas and Bolinao, Pangasinan in Luzon Island, Philippines, according to the Bureau of Fisheries and Aquatic Resources (BFAR)
The massive fish kill was initially reported to have been caused by the restiveness of Taal Volcano, an active volcano currently being monitored by authorities due to signs of possible eruption. The volcano is surrounded by the lake where the fish kill took place.
"However, the Philippine Institute of Volcanology and Seismology (Phivolcs) clarified to reports that the recent activity of Taal Volcano is not related to the fish kill, which was said to have cost about P33 million", Batangas Today reports.
BFAD and local authorities in Batangas are looking at sudden temperature change which may have caused the massive fish kill in the lake.
"Talisay agricultural officer Zenaida Macatangay said an initial investigation showed the deaths may have been caused by the temperature change as the rainy season set in last week after a scorching summer, which also depleted the lake's oxygen levels", ca.news.com reports.
The BFAR explained that fish kills are commonly triggered by diseases from bacteria, fungi, parasites, natural toxins, pollutant toxins, oxygen depletion and viruses, among others.
Meanwhile, another fish kill occurred Sunday in Bolinao, Pangasinan, a fishing community located about 200 kilometers north of Manila.
"Prestiliano Onzaga, fishery extension worker of the Anda town government, said some 50 tons of bangus cultured in fish cages in the Kakiputan Channel and in the waters off the villages of Awag and Narra in Anda turned belly up", Inquirer.net reports.
The Bolinao fish kill is also being blamed on the sudden rise in water temperature following the passage of a typhoon which carried heavy rainfall in the northern part of Luzon, according to Nestor Domenden, BFAR regional director.
"Domenden said the dissolved oxygen level in the Kakiputan Channel in Anda and Bolinao on Sunday was 0.9 milligrams per liter (mg/l), way below the 4 mg/l minimum level where fish could survive", the report added.