The calm waters of Taal Lake are deceiving, and what lies below may be toxic. Fish cages have poisoned the sediments below while surface waters remain relatively safe for fisheries, according to a study made by the University of the Philippines Manila (UPM), the first ever to look at the impact of intensive aquaculture on Taal Lake. "The results clearly demonstrate that fish cage culture has harmful impact on lake quality, particularly the sediments," says Arnold V. Hallare of the department of biology of the UPM College of Arts and Sciences, the lead researcher of the study on fish cages off Agoncillo and Laurel towns and, for comparison, the waters off Tanauan where there are no fish pens.

Icamina, P. (2010, February 4). Aquaculture poisoning Taal Lake. Malaya Business Insight pp. A1, A6.