By Carlos N. Santos-Viola
Philippine Daily Inquirer
DateFirst Posted 22:05:00 11/14/2010
The volcano and lake contain towns submerged by several eruptions across the centuries
ONE OF THE MOST popular panoramic vistas nearest Manila is located in Tagaytay City, Cavite. Owing much to the view of the 26,000-ha Taal Lake and its active volcano island with the backdrop of the Batangas and Laguna sierras, the Taal calderas present the most spectacular view in the country.
History tells us that Taal?s volcano has erupted 41 times since 1595. The Batangas towns of Tanauan, Lipa, Bauan and Taal have literally moved three or five times from their original locations due to the destructive boulders, sand, ash and mud laced with sulfuric acid unleashed by the volcano. Records also describe how spectators from hundreds of kilometers away watched Taal volcano throw thunderbolts several kilometers into to the sky, while nearby residents were horrified seeing the destruction it rained upon their land. In 1754 the volcano is even said to have erupted continuously for six months.
Located on the lake?s southwestern shore is the 8.2-km-long Pansipit River. Its lakeside mouth starts in San Nicolas, passing through Agoncillio then ends in the town of Lemery fronting Balayan Bay, facing the South China Sea. Although surrounded by 37 streams, this lone feeder river is the lake?s primary source of water. Taal Lake also receives an annual average rainfall of 2,026 millimeters a year during the months of June to October.
Pansipit was once wide and deep enough to welcome Spanish galleons?and saltwater flora and fauna. Over the centuries, the multiple volcanic eruptions eventually changed its dimensions, transforming what was a bay into a lake. But even as the river narrowed and became shallower, migratory fishes continue to spawn in the lake where most of their fingerlings stay inside, adapting to the freshwater environment. Currently, jacks, snappers, turtles, banded sea snakes, tarpons, smelt, damsel fish, mullets and other species take up residence in the lake together with freshwater fishes endemic to the area. Famous among its fauna are the sardines (tawilis) and the jacks (maliputo).
Other familiar species that retain the names of their saltwater counterparts include turtles (pawikan), large milkfish (sabalo), eel (igat) and red snapper (maya-maya). Taal has a sea snake (Hydrophis semperi) similar to its saltwater counterpart with venom as potent as that of land-dwelling cobras. Although not much can be read about this snake, this species is supposedly found only in Taal?s waters. This snake also has a local relative called the file snake or acrochordus granulatus. One can tell that this snake is not venomous like its neighbor by noticing that its tail is not paddle-shaped, and the white bands around its hide are not continuous. A transcript dating to 1754 also indicated the presence of sharks and even alligators in the lake.
Of the lake?s 120 kilometers of shoreline, the most popular side is at Talisay, just below the 640-m (2,100-ft) Tagaytay ridge. This section is accessible either from the ridge or through the Sambat Star Toll exit. The lake?s average depth is 60-65 m and the deepest is 160 m.
Although we have made previous dives beside the volcano island, this time we decided to dive along the mainland coast. Accustomed to the clear seawater, our new rockskipper team member, Bea L. Nakpil, was quite hesitant in plunging into Taal?s freshwater. Intrigued by the book ?The Mysteries of Taal? written by professor Thomas Hargrove, which describes the numerous dives and discoveries he made along Talisay and Balete, we chose a spot called Balas where the town of Tanauan was supposedly originally located before 1754. Hargrove wrote about finding the town?s submerged ruins along this shoreline.
We chose Holiday Resort as our base, as well as our beach entry and exit points. The resort had a very minimal but comfortable facility which caters to activities such as camping, line fishing, sailing and trekking in the volcano island.
The locals were surprised to see that we were actually going to dive in the lake. Although they knew of the sapao or rock formations present in the lake, they did not seem to know much of its origins.
Accustomed to clear waters, some of us were having second thoughts diving in the lake with very limited visibility. Nevertheless, we proceeded with care, following our dive plan to the letter. Knowing the presence of lush, thick Vallisneria spiralis and Hudrilla verticilatas, we snorkeled over them and noticed they were as tall as the depth where they grew.
After swimming 50 meters out, we shifted using scuba and started our descent using our float line, making sure everyone was in touching distance and had a hold of our buddy line. We touched bottom at 6 m (20 ft) where the lake grass was still present, but not as abundant and tall. After a minute of acclimatizing with the 1.2-m (4-ft) visibility, we followed our planned compass heading, until we reached a depth of 9 m (30 ft). From there we turned left. Due to lack of penetrating sunrays, the vegetation ended at a depth of about 7.6 m (25 ft). There were seemingly undisturbed piles of vacant unionaceans or elongated mollusks, about 10 cm in length, covered with brownish algae. Spongillidae or white branching sponges sprouted at random. Gourami fishes 10-15 cm (4-6 in) in length thrived along the grassy borders, and were startled by our presence. These fishes are just one of the 52 species recorded.
Visibility improved by 1.8 m (6 ft) in the deeper areas. Though we encountered small areas with thermocline and halocline, the water was quite still with no evidence of any current.
The bottom sloped to about 45 degrees starting at depth of 7.6 m (25 ft). We could not see beyond 4.6 m (15 ft) further below due to the predominant brownish tint. After swimming for 50 minutes at 9 m (30 ft) with still a lot of air in our cylinders, we decided to end our dive unfulfilled after not seeing any sign of the sapao.
On a separate day, we made another dive in Balas. We swam in the opposite direction, weaving the slope at 9-12 m (30-40 ft). Water visibility was a little better, allowing a clearer view of the fishes and bottom substrate. Small empty Corbicula manila clam-like shells littered the bottom with larger clusters of Spongillidae.
After 30 minutes we swam back and came across an unusual massive outcropping, like uniformly stacked smoothened rocks (turtle shell-shaped) about 30 by 20 cm (12 x 8 in) each covered with black-brown algae-type material. Bea was ecstatic seeing the unusual formation. We decided to slightly chip an inch-wide off the surface, and then noticed white coloration underneath. The texture was not of cement, but was quite brittle. Although it didn?t look like a well-carved wall, its shape and uniformity did not seem to resemble a natural formation either.
We further surveyed the surrounding area to see the extent of this formation. We later marked it with our descent line, terminated our dive and took land fixes from our surface float to mark the spot.
Piece of history
Dr. Hargrove mentioned in his book of old church walls in Taal made of hewn coral blocks. Recalling the white coloration and texture of the chipped rock we saw, we could say our dives were productive.
Although it would take an archeologist to confirm our speculation, we strongly feel that what we saw was part of a ruin from an ash fall, and we are content to leave it at that for the time being. Who knows what else we might discover in the habitats of Taal Lake?s flora and fauna?