Depleted level of dissolved oxygen in waters of Brgy. Buso-buso and Gulod in Laurel and Brgy. Bañaga in Agoncillo, Batangas triggered a fish kill reported on May 29. The total allowable number of fish cages in Taal Lake is 6,000 units. Of this, only 121 units or 2% were affected by the fish kill. This resulted to over 600 metric ton (MT) losses of tilapia stocks amounting to a total of P43.13 million.

The DA-BFAR conducts regular monitoring of water quality including dissolved oxygen level in Taal Lake. Last week, the agency, through its Calabarzon Regional Office, issued an advisory for fish cage operators to closely watch their stocks after the agency noticed a drop in the dissolved oxygen level. Fish cage operators in areas where dissolved oxygen level is down were promptly advised to start emergency harvest of marketable sizes of tilapia and use oxygen pumps or aerators as part of mitigating measures.

While heavy rain, sudden change of wind direction and intense heat caused the fish kill, the DA-BFAR observed that the overstocking of fish cages in the areas affected also contributed to the depletion of dissolved oxygen in the lake. The agency reiterates that the risk for fish kill can be reduced, if not totally prevented, if fish cage operators adhere to good aquaculture practices where proper stocking density and feeding are observed.The DA-BFAR, while expresses regrets over the economic losses of those who are affected, is confident that the incident which hit only 2% of the total number of fish cages will not cause general surging of tilapia market price. The agency assures the public that supply of tilapia will not be severely disrupted.

The DA-BFAR will continue to conduct water quality monitoring and will ensure that fish cage operators are properly advised and provided with the necessary technical assistance. ###