December 25 is regarded as the most joyous day of the year, as the majority of Filipinos commemorate the birth of Jesus Christ. However, in Cadiz City in Negros Occidental, this day serves as a somber reminder for its residents of the demise of 33 giant clams residing within the 9.2-hectare Giant Clam Village (GCV).
The city government of Cadiz has designated GCV as a protected marine area, which is positioned adjacent to the famous Lakawon Island in barangay Cadiz Viejo. The cause of death is linked to sea poachers, whose identities remain undisclosed.
The incident came to light on Christmas Day when routine patrols detected suspicious activities within the restricted area, prompting an immediate investigation by local authorities.
In a press release, Cadiz Mayor Salvador Escalante, Jr. announced a reward of P20,000 for any credible information leading to the identification, arrest, and prosecution of those responsible for this incident.
Escalante condemned this reprehensible act against the giant clams as a form of “environmental terrorism” and vowed that such an act would not be tolerated in their city. “You gave us the hardest lesson,” he warned the suspects. “We will give you the hardest retribution just in case.”
Giant clams – which can grow to 1.5 meters (nearly five feet) in diameter and weigh more than 200 kilograms – are a protected species in the Philippines. Gathering, collection, and possession are prohibited under Philippine law.
All species of giant clams are listed under Appendix II of the Convention on International Trade in Endangered Species (CITES). Although they are not currently threatened with extinction, they may become so without trade controls. Trade is only allowed if the exporting country issues a permit based on legal acquisition and no detriment to survival.
Giant clams are harvested for food. “Though the soft body parts account for about 10% of the body weight, it is nearly pure, healthy protein,” says Oceana, an international group focused solely on protecting the world’s oceans.
The meat of giant clams is reported to command prices ranging from P6,000 to P8,000 per kilogram. In Japan, this delicacy is referred to as “himejako.” Various Asian cuisines incorporate meat derived from clam muscles. In China, significant sums are offered for the adductor muscle, which is believed to possess aphrodisiac properties.
There is some truth to the assertion regarding its aphrodisiac qualities. Vicky Viray-Mendoza, the executive editor of Maritime Review Magazine, wrote: “American and Italian researchers collaborated to study these bivalves and discovered that clams are abundant in amino acids that stimulate an increase in sex hormone levels.”
Some experts believe the high zinc content found in giant clams may contribute to testosterone production.
Currently, giant clams are prized for their shells. Often referred to as the “jade of the sea,” these shells are considered a substitute for ivory from elephant tusks. A report by Science indicated that these shells can be sold for prices between P150,000 and P600,000.
In China, where they are particularly popular, the shells are crafted into carvings, jewelry, and other decorative items, serving as status symbols for the affluent and as protective charms in Chinese Buddhism.
Giant clams represent the largest extant species of bivalve mollusks. Contrary to their portrayal in popular films as “killer clams,” there are no reliable cases of individuals being ensnared and drowned by these creatures.
Typically, giant clams inhabit coral reef environments, usually at depths not exceeding 20 meters. These clams are frequently located in shallow lagoons and reef flats, where they are often found embedded in sandy substrates or in areas consisting of coral debris.
“The giant clam gets only one chance to find a nice home,” according to a National Geographic report. “Once it fastens itself to a spot on a reef, there it sits for the rest of its life.”
Giant clams also 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. “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 beautiful, bright colors characteristic of individual giant clams is actually a result of the symbiotic algae.”
Giant clams, due to their substantial weight of up to 250 kilograms, are unable to move. Consequently, they engage in external fertilization, releasing both eggs and sperm into the water simultaneously. Despite being hermaphroditic, they are incapable of self-fertilization. According to Oceana, they can reproduce with nearby individuals.
Giant clams may have existed even during the time when dinosaurs roamed around this planet. “They have been around for over 38 million years,” wrote Viray-Mendoza. “Antonio Pigafetta, the Italian navigator who joined Ferdinand Magellan in his sea travels around the world, documented these giant clam species as early as 1521 in his journal.”
“We need to do something now before giant clams become extinct,” urges Dr. Rafael D. Guerrero III, a fishery expert and an academician with the National Academy of Science and Technology (NAST).
Dr. Guerrero, however, believes there’s still hope for giant clams. “To save our giant clams, we should protect them in the wild from poachers (particularly foreigners) and promote their sea farming,” he suggested.
In the Philippines, places with giant clam conservation areas are found in Island Garden City of Samal, Davao del Norte; Silaki Island, Bolinao, Pangasinan; Binduyan and Ulugan, Palawan; Sinandigan, Ubay, Bohol; Sitangkai, Tawi-Tawi; and Cadiz Viejo, Cadiz City, Negros Occidental.
In Samal City, a group of fisherfolk from barangay Adecor in the Kaputian District has established an organization dedicated to a shared objective: the preservation of the dwindling populations of endangered giant clams.
The Adecor United Fisherfolk Organization (AUFO) serves as the custodians of the giant clams raised in Samal water and under the supervision of the local government unit of IGACOS.
Preservation efforts started in 1999 when the area was declared a marine park. It got a major boost when the University of the Philippines-Marine Science Institute provided the much-needed support through its Giant Clam Enhancement Program.
Today, the protected sanctuary is home to over 3,700 giant clams with around 3,000 considered mature. There are six different species of giant clams in the area. These are Tridacna gigas (true giant clam), T. deresa (smooth giant clam), T. squamosa (fluted giant clam), T. maxima (elongated giant clam) , T. crocea (boring clam), and T. noae (Noah’s giant clam or teardrop clam). The latter is considered a resurrected species, being endemic in the area.
The Davao del Norte State College (DNSC) supervises the project. In response to the call for conservation and increasing interest among the locals and international tourists in giant clams, DNSC partnered with the AUFO and launched the Taklobo Tours in 2013.
The two-hour Taklobo Tours features a one-hour snorkeling experience in the designated area. Guests are transported via a motorized banca from the shore to a floating cottage, where they receive an introduction to the significance of giant clams. The docking area can accommodate 30 to 35 individuals, while the viewing deck is limited to 10 to 15 persons.
Following a brief orientation, visitors are instructed to wear life vests, and those interested are provided with snorkels and masks. They then proceed to swim to the location where the giant clams are beautifully arranged on the sea floor. Due to the clarity of the water, they can observe the vibrant giant clams, resembling a blooming garden, in shades of blue, violet, yellow, green, and brown. Touching the giant clams is strictly prohibited.
What started as a conservation initiative has evolved into one of Samal’s most sought-after attractions for visitors. “Incredible and motivating marine sanctuary that safeguards various species of giant clams,” remarked a tourist who has experienced the Taklobo Tours. “Equipped with our snorkel masks, we were guided underwater by a certified instructor to observe these remarkable sea creatures up close.”
