The Philippines is rich in flora and fauna, with some species considered endemic or can be found only in the country. These include the locally known taklobo (Tridacna gigas)—the largest bivalve mollusk in the world that can weigh over 250 kilograms and grow up to five feet.
Despite its gigantic size and longevity (it can live up to a hundred years), however, this giant clam has become scarce.
Declared extinct in the 1980s due to poaching, destructive fishing practices, and water pollution, the late National Scientist Dr. Edgardo Gomez, who is also a former Malampaya Foundation Inc. (MFI) trustee, took broodstock of the taklobo from the Pacific Islands to breed at the University of the Philippines Marine Science Institute (UP MSI) to sustain the species in the country.
For more than three decades, the UP MSI, of which Gomez was founding director, successfully cultured nonnative taklobos from these tropical islands.
After a lead from a Palaweño marine scientist in 2017, the MFI team and Gomez went to Puerto Princesa, Palawan, to survey and confirm the presence of five closely-guarded, remaining potential spawners of the Philippines’s true native Taklobo in Honda Bay.
The discovery sparked a light of hope that amplified initiatives to restore the healthy population of the locally-extinct Philippines’ true native clam together with other shell species through the String of Pearls project, backed up by the recently launched community fundraiser Adopt-a-Shell project.
Historic milestone
Despite the pandemic, MFI reported the milestone of having spawned 132 million of the native taklobo at the end of 2020. Once mature, they will be deployed to effectively managed marine protected areas (MPAs) and marine management zones in select coastal reefs in north Palawan, Oriental Mindoro, and Batangas.
Clams are indicators of a healthy and sustainable marine ecosystem. Like others, the taklobo prevents algal blooms that lead to depletion of oxygen in the water, which marine life needs to survive.
The large population of clams also helps in creating fish habitats—on a larger scale given their size—because they give off calcium carbonate that is incorporated into coral reefs.
Despite their pivotal role, however, taklobos are not spared from local and foreign poachers, who sell giant clam meat and shells for a hefty price in the black market. In 2020 and early this year, several incidents of clamshell poaching reached the media and were made public.
Last March alone, 324 shells of taklobos weighing 80 tons were confiscated from poachers. This was followed by the seizure of P1.2 billion worth of illegally harvested giant clams with a total weight of 200 tons.
Return of colonies
A group of clams is known as “bed.” Giant clams are rare because they are hard to propagate naturally. Even if they release millions of sperm and eggs in the water, survival rate ranges from 0.01 percent to 3 percent only. This is where restocking comes in to repopulate the “locally extinct” giant clam species.
With the limited number of taklobos, dedicated members of MFI and partner Western Philippines University, whose marine station in Palawan was upgraded by MFI, needed to collect eggs and sperm from the source.
In June 2019, they conducted the first in-site spawning of an estimated 9.5 million eggs in Honda Bay with UP MSI.
Once the larvae or baby clams were mature enough under careful cultivation, these were deployed or restocked to other MPAs under effective management by a partnership with communities and local government units.
Restocking includes other species like abalone (sobra-sobra) and topshell (samong)—the first to be restocked by MFI and WPU since 2014. By end-2020, a total of 1,655 giant clam juveniles and 1,100 abalone juveniles have been restocked.
To help in the propagation efforts, the Adopt-a-Shell project needs community support. Concerned citizens and institutions are encouraged to care for the shells and help restock Philippine reefs in well-managed MPAs for as low as P500 monthly contribution, covering care for one settlement plate of 40 to 50 taklobo larvae. We need to help propagate our near-extinct taklobos because they also help make a healthy and sustainable Philippine marine ecosystem.