CALAMBA CITY, Laguna -- Concerned government agencies in Calabarzon are intensifying efforts to get to the bottom of the latest fish kill phenomenon which hit the Taal Lake coastal towns of Laurel and Agoncillo and has now spread to Talisay in Batangas.

Estimated losses due to fish kill in both Laurel and Agoncillo towns have reached more than 605 metric tons over the weekend.

Wilfredo M. Cruz, regional director of the Bureau of Fisheries and Aquatic Resources (BFAR) in Region 4-A (Cavite, Laguna, Batangas, Rizal and Quezon) has reported that results from their water quality sample monitoring over the affected waters in the coastal villages of Agoncillo, Laurel, and Talisay towns on Saturday indicated low level of dissolved oxygen in water associated with fish kill measuring 3.0 mg/l.

This level was way below the normally acceptable continuous level of dissolved oxygen in water for fish culture of at least 6.0 mg/l.

Water samples at the surface level have been obtained in Agoncillo town’s Barangay Bañaga at 1.66 to 2.89 mg/l and Bilibinwang at 3.66 to 4.96 mg/l; Barangay Leviste at 3.81 to 4.63 mg/l and Buso-buso at 0.18 to 1.81 mg/l in Laurel town; and Barangay Quiling at 2.60 to 3.89 mg/l and Sampaloc at 1.51 to 3.15 mg/l in Talisay town.

Cruz has called on Local Government Units (LGUs) surrounding the Taal Lake to urge fish cage operators to intensify their monitoring and whenever possible, to harvest their already marketable fish stocks ahead of schedule.

BFAR also encouraged the Taal Lake fish stakeholders to prepare their oxygen tanks, pumps and engine sets, including the necessary equipment to move their fish cages to the lake areas where the water quality is normal to avoid fish mortality or fish kill.

According to Nenita Kawit, chief of BFAR-Calabarzon’s Batangas Inland Fisheries Technology Outreach Station (BIFTOS) based in Ambulong, Tanauan City, the Fisheries and Aquatic Resources Management Council (FARMC) in Balete, Batangas has reported the occurrence of green discoloration of the lake water in their area as early as April 8 this year and a few muang ang guno fishes were sighted floating dead on the water surface.

Meanwhile, Department of Environment and Natural Resources (DENR) Calabarzon Regional Executive Director, lawyer Maria Paz Luna, has reported over the weekend that the fish kill has affected some 121 fish cages, causing the deaths of some 605 metric tons of fish in the Taal Lake coastal towns of Agoncillo and Laurel.

“The 121 affected fish cages are from Barangays Buso-buso and Gulod in the town of Laurel and Bañaga in Agoncillo,” Luna said.

“The fish kill is not expected to affect the supply and prices since the volume comprises only a small percentage of fish supply, mostly tilapia in the market and not a cause for alarm to the public,” she added.

She added that fish owners were immediately advised to move their fish cages or harvest their stocks early to avoid taking mortalities.

She also reported that site inspection in Taal Lake's affected areas on Thursday revealed around 200 metric tons of dead fish floating, which is simply too many to be buried in "mortality pits."

As of Friday, around 33 fish cages were still found with floating dead fish prompting the affected fish stakeholders to dig mortality pits.

She said the overcrowding in the fish cages is among the triggering factors that resulted in the reduction of dissolved oxygen in the lake waters, thus the Batangas provincial government and the newly-created task force helped in dismantling the cages.

Luna, however, assessed that despite the rules, the fish cage stocking density is routinely violated because regulators have no way to count the fish already in the cages.

“The industry is incapable of addressing large fish kill incidences due to lack of large harvesters. The mortality pits certified as existing were nowhere to be found and the free trainings that all caretakers have attended were might as well have been in a foreign language,” she noted. (Zen Trinidad/PNA)