The Adecor United Fisherfolk Organization, composed of more than a dozen members, serves as caretakers of thousands of giant clams transplanted through the Giant Clam Stock Enhancement Program of the University of the Philippines–Marine Science Institute (UP‑MSI). These fisherfolk are “trying to save some of the country’s remaining endangered species of giant clams.”
The sanctuary, officially called the Marine Reserve Park and Multipurpose Hatchery, is supervised by the IGACOS local government and supported by Davao del Norte State College. Beyond conservation, the project also provides livelihood and raises public awareness through Taklobo Tours, an ecotourism activity launched in 2013.
Visitors ride a motorized banca to a floating cottage, receive basic snorkeling instructions, and swim over crystal-clear waters where giant clams thrive. One tourist described the experience as an “awesome and inspiring marine sanctuary that protects several species of giant clams… A definite must-see.”
The 14‑hectare sanctuary hosts four introduced species: Tridacna gigas, T. deresa, T. squamosa, and T. hippopus. Of the 3,500 clams originally transplanted in 2001, only 2,196 remain, but the fisherfolk have successfully raised 800 juveniles—an encouraging sign for stock enhancement.
Giant clams play a vital ecological role. As Dr. Cecilia Conaco of UP‑MSI explains, they “build and shape reefs aside from filtering water and recycling nutrients.”
More importantly, they provide shelter for different organisms. Serving as substrates of corals and sponges, marine biologists say giant clams – which can live in the wild reportedly up to over 100 years – help increase the residence of fishes and act as hiding places for other marine organisms.
“Like most corals, some anemones, and other reef organisms, giant clams utilize a combination of methods to obtain food,” explains Oceana, an international organization focused solely on protecting the world’s oceans. “The majority of their energy is derived from symbiotic algae living within their cells, providing the clams with excess energy that they make via photosynthesis.”
In return, “the algae have a safe to live and receive the nutrients necessary to photosynthesize. The giant clams provide those nutrients by filtering feeding small prey from the water above the reef surface, which it siphons through its body. The beautiful, bright colors characteristic of individual giant clams are actually a result of the symbiotic algae.”
As giant clams cannot literally move due to their heavy weight (as much as 250 kilograms), they reproduce via external fertilization, where eggs and sperm are released into the water column at the same time. Although they are hermaphrodites, they cannot self-fertilize. “They are able to reproduce with other individuals that are close by,” Oceana explains.
Most Filipinos don’t know this and in fact, they have no idea about the real status of giant clams thriving in the country’s waters. Recently, these marine creatures made headlines when Chinese fishermen were caught poaching giant clams from the West Philippine Sea.
Although not endemic, the Philippines is one of the few countries where eight of the world’s 12 giant clam species can still be found. Many of these species are listed as endangered or vulnerable by the International Union for Conservation of Nature (IUCN).
However, their populations continue to decline due to overharvesting, habitat degradation, weak enforcement of regulations, and inconsistent conservation support. Dr. Conaco warns that “we need to do something now before giant clams become extinct.”
Giant clams have existed for over 38 million years, with early documentation dating back to Antonio Pigafetta in 1521.
The clams’ high market value contributes to their exploitation. Their meat, considered a delicacy in Japan and believed to have aphrodisiac properties, sells for ₱6,000–₱8,000 per kilogram. Their shells—dubbed “jade of the sea”—are even more valuable, fetching ₱150,000 to ₱600,000 and used for carvings and jewelry.
To curb exploitation, giant clams are protected under the Philippine Fisheries Code (RA 8550), which prohibits collecting, selling, or exporting them. Violators face fines of ₱300,000 to ₱3 million and imprisonment of five to eight years.
Despite the challenges, experts remain hopeful. Dr. Rafael Guerrero emphasizes that protecting giant clams in the wild and promoting sea farming are key strategies. As he asserts, “To save our giant clams, we should protect them… and promote their sea farming.”
In Samal, the fisherfolk of Adecor prove that community‑based conservation—rooted in livelihood, education, and ecotourism—can help secure the future of these ancient marine giants.
Giant clam conservation and restocking projects in the Philippines are spread across roughly 40 nationwide sites, primarily managed by academic institutions, local government units, and foundations.
In addition to Samal, another significant giant clam initiative is situated in Bolinao, Pangasinan. This area hosts the Silaqui Ocean Nursery on Silaki Island, which is overseen by the Bolinao Marine Laboratory of UPMSI and is acknowledged as a key breeding site.
Danjugan Island in Sipalay, Negros Occidental, is the location of Project SEED, an environmental restoration program initiated by the Philippine Reef and Rainforest Conservation Foundation, Inc. (PRRCFI). This project incorporates a marine conservation aspect aimed at restocking and reseeding at-risk giant clam populations within coastal ecosystems.
In Palawan, there are several restocking and hatchery sites that are managed in collaboration with Western Philippines University, encompassing areas such as Taytay, Puerto Princesa, and Port Barton.
Marine protected areas in Calaca (Batangas) and Playa La Caleta (Morong, Bataan) are actively involved in the maintenance of reseeded clam populations. In Cadiz City, Negros Occidental, the local government administers the Giant Clam Village Protected Area.
