GENERAL SANTOS CITY (MindaNews / 5 Feb) – Around P5.2-million worth of tilapia have been devastated as another fish kill hit anew portions of the critical Lake Sebu in South Cotabato in the last three weeks.
Rudy Muyco, Lake Sebu town’s lake warden, said Wednesday the continuing fish kill has already destroyed a total of 68.291 metric tons (MT) of fingerlings and adult tilapia from fish cages situated in the lake’s eastern and western section.
Citing the prevailing market prices, he valued the damage at P85 per kilo for the adult tilapia and P150 for the hybrid fingerlings.
As of Wednesday, he said the fish kill already affected around five hectares of fish cages and a total of 54 operators.
“The fish kill is still ongoing in some portions of the lake and the situation might get worse in the coming days due to the erratic weather condition,” he told MindaNews on the phone.
Muyco said the latest fish kill, which is the first this year, was caused anew by kamahong, a phenomenon that is mainly caused by the sudden rise in the water’s temperature.
He said several fish cage operators initially reported the problem in some portions of the lake last January 13 after the area’s weather condition suddenly changed due to a low pressure area that affected parts of Mindanao and Visayas.
Kamahong, which usually occurs during the rainy season, triggers the rise of sulfuric acid in the lake’s waters that eventually caused the massive fish kill, provincial fishery coordinator Rex Vargas earlier said.
“It occurs when cold rainwater, which is heavier than warm water, settles at the abyssal zone of the lake. This causes the upturn or upwelling 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,” he explained.
Vargas 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 October last year, around 20 MT of harvestable tilapia and pangasius valued at around P1 million were devastated due to a fish kill that affected some 60 fish cages in the area.
In 2012, around 57 MT of tilapia were destroyed in two fish kills at the lake that were blamed on kamahong.
The initial fish kill in January 2012 ravaged some 48.55 MT of tilapia. It affected 48 fish-cage owners and left a total damage of P3.8 million based on tilapia’s market price of P80 per kilo.
In August that same year, an additional 8,000 kilograms of tilapia, valued at around P650,000, were destroyed in another fish kill that affected 14 fish cages at the lake.
Muyco said the municipal government is presently preparing for the scheduled dismantling starting next week of illegal fish cages along the lake as a strategy to prevent future fish kills.
“The lake is overcrowded. We need to significantly reduce the number of fish cages to its carrying capacity to resolve these problems,” he said.
Muyco said that based on their assessment, Lake Sebu currently hosts a total of 4,800 fish cages or around 1,800 more than its carrying capacity.
The municipal government of Lake Sebu and the provincial government of South Cotabato earlier issued a demolition order for all illegal fish cages at the lake.
Among the fish cages that were targeted for demolition were those that have no permits, sub-leased by their original owners and situated in the lake’s inlets and outlets.
Muyco said the two local governments earlier gave fish cage operators and owners until January 30 to demolish their illegal fish cages but it was extended to February 11.
“Around 65 fish cages have been so far demolished by their owners and this is continuing as we speak. By next week, we expect this number to reach around 1,000,” he added.