Batangas fish cage operators warned of Taal Lake fish kill

Batangas – The Bureau of Fisheries and Aquatic Resources (BFAR) yesterday warned fish cage operators in Batangas of a possible fish kill at Taal Lake due to the low level of oxygen in waters of three fishing municipalities.

Lea Villanueva, BFAR-Calabarzon assistant regional director, said they found a “very low” level of dissolved oxygen in lake waters in the towns of Agoncillo, Laurel and San Nicolas.

Last April, Villanueva said the coastal town of Mataas na Kahoy experienced a minor fish kill that affected 10 to 20 metric tons of fish.

“With the rainy season fast approaching, overturns or resurfacing of decomposed materials and bacteria from the bottom of the lake can cause depletion of oxygen and will lead to fish kill,” Villanueva said.

Villanueva said the oxygen level was recorded yesterday morning at 3.2-4.7 ppm (parts per million) below the ideal oxygen level of above 5 ppm for bangus (milkfish) farming in areas like the Taal Lake.

As pre-cautionary measure, Villanueva advised fish farmers to harvest their fish stocks that have reached “harvestable size” and transfer their fish cages to areas with higher oxygen levels.

“These naturally occurring phenomena are usually affected by temperature changes, especially in the warm months of April to August and during the rainy months when typhoons occur,” she said.

“We already sent a technical team to monitor the situation in the area and conduct regular advisory to the fish cage owners and their maintenance people about the impending fish kill,” she added.

Villanueva said the Bureau of Soil and Water Management of the Department of Agriculture lent water pumps and aerators last year to improve the quality of water in Taal Lake.

In 2011, fish kills hit the towns of Mataas na Kahoy and Cuenca and Lipa City, leaving at least 20 metric tons of bangus and tilapia dead.