KORONADAL CITY, Philippines—Nearly 50 tons of tilapia were lost in fishkills that have struck Lake Sebu in South Cotabato since Friday, prompting fisheries officials to issue a ban on the sale and consumption of fish harvested from the lake.
While officials said the fishkill could be an effect of climate change, they also blamed fish-cage operators for what appeared to be the consequence of excessive fish growing.
Rex Vargas, coordinator of the Bureau of Fisheries and Aquatic Resources in South Cotabato, said that since Friday, some 49 metric tons of dead fish had been retrieved from Lake Sebu, a 354-hectare natural lake located at the town of the same name.
Vargas said the fishkill damaged about P3.8 million in investments and devastated some 50 fish cages.
Tilapia production is a major industry in Lake Sebu town, earning for it the title of Central Mindanao’s tilapia capital.
The biggest fishkill occurred last Saturday, when some 46.5 tons of tilapia were fished out of the lake.
On Monday, Vargas said 2.5 tons more had been fished out from the lake.
Rudy Muyco, fish warden of the Lake Sebu agriculture office, said they had been telling fish-cage owners to observe strict fish spacing because overproduction had been found to be one of the causes of previous fishkills.
Muyco cited last year’s fishkill, during which some 13 tons of tilapia had also been wasted.
He said fish experts had found that the fishkill, which occurs almost annually, was due to low oxygen level at the lake and changing water temperature due to the erratic climate pattern.
Overstocking and water pollution, probably from feeds, were the cause of the lowered oxygen level, he added.
As in previous fishkills, Muyco said fish-cage operators had been told to temporarily stop feeding their surviving fish for at least a week to allow the water’s oxygen level to normalize.
Meanwhile, BFAR has issued an advisory banning the sale and consumption of tilapia harvested from Lake Sebu while the fishkill was being addressed.
“We ask consumers to avoid buying and eating tilapia from Lake Sebu until further notice from us,” Vargas said.
Dr. Rogelio Aturdido, South Cotabato health chief, said eating fish from the fishkill could cause abdominal discomfort and diarrhea.