The reason: this fish species (Sardinella tawilis) is endemic to or found only in the 24,400-hectare inland body of water in Batangas.
Until 1999, tawilis had accounted for 57 percent of the fish caught in Taal Lake, the country’s third largest lake, according to studies.
In recent years, however, fishermen in towns around the lake have noticed that tawilis has become scarce, primarily due to excessive exploitation of the fish resource. Pollution has also contributed to the problem.
Sardinella tawilis lives only in freshwater. Its nearest relative, Sardinella albella, more known as tamban or tunsoy, thrives in the sea.
In the English language, tawilis is called bonbon sardine or freshwater sardinella.
Tawilis eats planktons or microscopic animals floating in the water such as rotifers, cladocerans, and copeds. It also consumes ostracods, crustaceans that wallow in mud at the lake bottom.
Scientific records show that tawilis was first described and recognized by a scientist surnamed Herve as a new species, Harengula tawilis, in 1927. It was also described by another scientist, surnamed Wongratana, in 1980.
In 1983, it was listed as one of the 18 species of sardinella in the Indo-Pacific region. Two years later, it was recorded as one of the 21 species of sardinella in the whole world.
In view of the diminishing population of this "mid-level carnivore," the Conservation Program for the Endemic Freshwater Sardine, Sardinella tawilis, in Taal Lake has been launched.
Behind the program are the Los Baños, Laguna-based Department of Science and Technology-Philippine Council for Aquatic and Marine Research and Development, Southern Luzon Zonal Center for Aquatic and Marine Research and Development (one of the five PCAMRD-coordinated zonal centers), Department of Agriculture-Bureau of Fisheries and Aquatic Resources-National Fisheries Biological Complex, and the University of the Philippines Los Baños (UPLB).
Also involved in the program are the Kilusan ng mga Maliliit na Mangingisda sa Lawa ng Taal, PUSOD Inc., and Tanggol Kalikasan.
The youth sector is also being harnessed in the concerted effort to conserve and preserve the lake. Last year, students of towns around the lake took part in an Ecological Youth Camp.