Saving a delicious and popular shellfish from extinction

MIAG-AO, Iloilo — A research project that aims to save one of the country’s most delicious and popular shellfishes from extinction is on.

Focus of the two-year R&D projects is the vanishing oriental angelwing or paddocks, scientifically named Pholas orientalis and locally known among Visayas as diwal.

The University of the Philippines Visayas (UPV) and the Bureau of Agricultural Research (BAR) have signed a memorandum of agreement (MOA) for the implementation of the project titled “Development of Hatchery Technique for the Oriental Angelwings, Pholas orientalis (Omelin, 1791).”

Signatories to the MOA were BAR Director Nicomedes P. Eleazar and Chancellor Glenn Aguilar of UPV, a four-campus autonomous unit of the UP System whose seat of administration is the main campus in this town 41 kilometers west Iloilo City.

The project’s general objective is to establish viable and more efficient techniques for the production of diwal spats (young bivalves) or seedlings.

Specifically, it will determine the following: fecundity of different sizes of adult diwal; the optimum ration of eggs and sperms for higher fertilization and hatching rates; the effects of different temperature, salinity, types, and amount of good items on the growth and survival of larvae and spats; and the best size of seedlings for dispersal that will end the hatchery process.

The project will also monitor and document the embryonic development of the eggs.

Diwal is one of the most important marine bivalves in the Philippines.

Found indigenously in coastal waters of Iloilo, Negros Occidental, Capiz and Aklan, it has become a major source of income for coastal fishermen.

It has emerged as a “tourist food attraction” in Roxas City, Iloilo City, and Bacolod City (Negros Occidental) owing to its succulent texture, sweet and juicy taste, and unique flavor.

However, because of overexploitation and destructive human activities, their population has decreased tremendously, and “tragically may soon face extinction if no intervention would be made,” warned Dr. Laureta, a multi-awarded marine scientist.

UP Visayas also stressed that traditional collection grounds of diwal through stocking of artificially produced seedlings should be rehabilitated.

“This strategy, coupled with strict implementation of conservation policies, has been successfully demonstration for several species of mollusks, crustaceans, and fishes in other countries such as Japan and Taiwan,” UPV noted.

Hatchery is a crucial and complementary aspects of the rehabilitation program for certain species, but as of now, the Philippines is way behind in the “seedling” or restocking the coastal areas to increase shellfish production, it stressed.

To complete the rehabilitation and sustain the production of possibly all traditional oriental angelwing grounds in Western Visayas, it is essential that diwal seedlings must be produced for this purpose and complement the already “broodstock transplantation” technology.

“With this, it is expected that we will have a multi-million peso diwal industry,” UP Visayas concluded.