Taal Lake is a freshwater lake located in the province of Batangas, on the island of Luzon, Philippines. It is formerly known as Bombon Lake, is 60 km south of Manila. It is the deepest lake in the Philippines (172 m) and the third largest in area (234.2 km2). The active Taal Volcano, which is the one responsible for the lake’s sulfuric content, lies on an island in the center of the lake, called Volcano Island. The island is called pulo or islet by the locals.
It is a caldera lake, having been formed partly by the collapse of a large volcanic crater and partly by subsidence. Subsequent volcanic activity has modified the morphometry of the lake. During the 10th century, it was connected to the sea at Balayan Bay by a wide channel, but an extremely powerful eruption of the Taal Volcano in 1754 rearranged the shape of the lake and narrowed the outlet to form the present day Pansipit River, the lake’s only outflow, which leaves the lake in its southwest corner and travels about 10 km to the sea.
One can even swim inside the Crater Lake but the lake’s water is a much diluted form of sulfuric acid with high concentration of boron, magnesium, aluminum and sodium in salt form. Its mean depth measures 20 m. In its dark water no life of fish is possible.
Taal Lake is situated in a highly populated and rapidly growing agricultural and industrial region.
The Philippine Government has designated the Taal region as a favored site for setting up new industries and infrastructures. The whole region surrounding Lake Taal is at considerable volcanic risk.
Overfishing is one of the biggest problems as well as the pollution of the lake through waste water from the industry and households. Unsustainable development presents also a very real threat to the lake.
Taal Lake is home to a venomous black and white “sea snake” (Hydrophis semperi). This species is one of only a few snakes of its type that breeds in freshwater. Taal Lake is also habitat of world’s only freshwater sardine, Sardinella tawilis. The bleniid Omobranchus ferox is also endemic to Lake Taal.