GENERAL SANTOS CITY (MindaNews/30 January) – A rise in water temperature has been blamed for a fish kill in Lake Sebu town in South Cotabato since last week.
Called “kamahong,” the phenomenon has killed 48.55 metric tons (MT) of tilapia, Rex Vargas, provincial fishery coordinator, said Monday.
He said an initial 46.05 MT were reported damaged as of last Friday. But he said another 2.5 MT were added to the reported damage Monday morning based on a report submitted by Lake Sebu municipal fishery coordinator Oding Kunan.
“Consumers are advised not to buy nor consume dried tilapia from Lake Sebu because of the fish kill,” he said in a report from the South Cotabato Information Office.
Lake Sebu town is a major producer of fresh and dried tilapia in Region 12 or the Soccsksargen Region.
Tilapia products from the area are sold in wet markets in the region, which covers the provinces of South Cotabato, Sultan Kudarat, Sarangani, and North Cotabato and the cities of General Santos, Cotabato, Koronadal, Tacurong, Cotabato and Kidapawan.
Vargas said a total of 48 fish cage owners were affected by the fish kill, which was so far valued at P3.8 million based on tilapia’s market price of P80 per kilo.
He said the accounted damage only covers those found inside the fish cages.
“We’re still assessing the damage for those outside the fish cages,” Vargas said.
Vargas said the Office of the Provincial Agriculturist has been closely monitoring the fish kill, which was the second occurrence recorded in the area since July.
“Kamahong,” which usually occurs during the rainy season, reportedly triggers the rise of sulfuric acid in the lake’s waters that eventually caused the massive fish kill.
“It occurs when cold rainwater, which is heavier than warm water, settles at the abyssal zone of the lake. This causes the water upturn or updwelling of warm water carrying silts, sediments, and gases such as hydrogen sulfide, ammonia, sulphur and methane gas produced by the decomposing organic matter such as fish feeds,” Vargas explained.
He said such situation results in the reduction of dissolved oxygen in the water, “forcing fishes to take in oxygen directly from the atmosphere and eventually die.”
In July last year, the occurrence of “kamahong” affected seven fish cages in Lake Sebu, destroying around 13 MT of tilapia worth P1.04 million.
The provincial government earlier acquired some 500,000 fingerlings of tilapia from the Bureau of Fisheries and Aquatic Resources (BFAR) to replenish the damaged fish stocks.
Vargas said their office submitted another request to BFAR on Monday for the acquisition of an additional 2.5 million tilapia fingerlings worth P625,000 for distribution to affected fish cage owners.
He said the local government will acquire the tilapia fingerlings at a discounted rate of 25 centavos each. (Allen V. Estabillo/MindaNews)