GENERAL SANTOS CITY—The municipal government of Lake Sebu in South Cotabato is planning to declare a state of calamity due to another major fish kill that has seen P6.5 million worth of tilapia destroyed.
Zaldy Artacho, Lake Sebu municipal agriculture officer, said Tuesday the fish kill started late last week in portions of the lake after its dissolved oxygen dropped to critical levels anew.
Artacho said the phenomenon, known locally as “kamahong,” came after a week of sporadic heavy rains in the area.
Several fish cage operators initially reported Friday that some of their tilapia appeared to be gasping for air, he added.
“By night time, the fish kill already started in a number of fish cages,” he said in a radio interview.
Artacho said a total of 72,335 kilos of tilapia have been destroyed, with the prevailing farmgate price for tilapia in Lake Sebu at P90 per kilo.
Artacho said the figures only come from 19 affected fish cage operators in Barangays Poblacion and Takonel. Validation and assessment is ongoing for other affected fish cage operators, earlier estimated at more than 300.
Some operators were forced to conduct massive emergency harvests over the weekend to save the remaining tilapia for sale, he said.
Mayor Antonio Fungan has ordered Artacho’s office and the fish kill-hit barangays to prepare the necessary data for the declaration of a state of calamity.
The mayor specifically directed the affected barangays to fast-track their calamity declarations.
Fishery officials had blamed the fish kill in Lake Sebu to “kamahong,” a phenomenon caused by the sudden rise in the water’s temperature.
“Kamahong,” which usually occurs during the rainy season, triggers the rise of sulfuric acid in the lake’s waters, which eventually causes massive fish kill.
The Office of the Provincial Agriculturist said the phenomenon occurs when cold rainwater, which is heavier than warm water, settles at the abyssal zone of the lake.
It causes the upwelling of warm water carrying silt, sediments and gases such as hydrogen sulfide, ammonia, sulphur and methane gas produced by the decomposing organic matter such as fish feeds.
The situation results in the reduction of dissolved oxygen in the water, “forcing fish to take in oxygen directly from the atmosphere, and eventually die,” the OPA said.
Last year, Lake Sebu recorded at least eight fish kills that destroyed around P1.4 million worth of tilapia.