July 01, 2011
RESULT OF TAAL LAKE WATER QUALITY MONITORING
As of June 30, 2011
BFAR ADVISES TAAL OPERATORS TO DISPOSE DEAD FISH PROPERLY
Following the latest water sampling in Taal Lake last June 30, BFAR Director Asis G. Perez appeals to fish cage operators in certain fish kill areas to remain vigilant in taking care of their fish stock due to the persisting low levels of dissolved oxygen or DO.
Perez said that, the DO levels of the water samples taken in Berinayan, Leviste, Busu-buso and Bañaga, all in Laurel as well as in Manalaw and Bilibinwang in Agoncillo are still very low, ranging from 3.07 to 5.40 parts per million (ppm). The normal DO for growing fish is 6.0 ppm.
However, the DO levels in the areas of Talisay, specifically in Aya, Quiling, Tumaway, Sampaloc as well as in Poblacion San Nicolas had greatly improved, now ranging from 7.40 to 8.10 ppm.
“Our fish cage operators in areas of low DO level should understand the importance of removing all dead fish in their cages and in properly disposing these in designated land areas,” Perez stressed.
He said that according to fish experts, dead fish release nitrogen and phosphorous into the water when it start to decompose. These substances are utilized by phytoplankton naturally present in the waters and leads to algal bloom. However, there are varieties of phytoplankton such as the Microscystis or blue-green algae that causes the so-called “gilik” or off-flavor and odor in freshwater fishes that feed on them.
Fish exhibiting “gilik” odor are unacceptable to many consumers and therefore fetches very low price in the market.
The BFAR monitoring team continues to monitor the water quality in 14 stations in Talisay, Laurel, Agoncillo and San Nicolas for the past thirty-nine (39) days following the fish kill onset in the later part of May.
Approved for Release: ATTY. ASIS G. PEREZ