Tripping with Tridacna

IT WAS easier to change the title to "Swimming with Tridacna" but I had to be honest, I didn't take a dip in the waters. Plus, you may be wondering what in tridacna are we talking about.

Tridacna is a genus of large saltwater clams, marine bivalve mollusks in the subfamily Tridacninae, the giant clams. Unfortunately, the global conservation status is listed as Vulnerable in the 2004 IUCN Red List of Threatened Species. All species of giant clams are listed in CITES (Convention on International Trade of Endangered Species of Flora and Fauna). In the Philippines, it is locally known as "taklobo."

The Davao del Norte State College (DNSC) in Panabo City was awarded the 2010 Ched (Commission on Higher Education) Best Regional Extension Award for its biodiversity and environment project, "Development Interventions in the Island Garden of Samal", which revolves around livelihood, cooperatives and harnessing community involvement in marine and environment protection. A program component is a Ched-funded project on the Conservation of the Endangered Giant Clams: A Strategy for Environmental Protection under Save Our Shore (SOS) Program.

The University of the Philippines-Marine Science Institute (UP-MSI) is distributing hatchery-produced giant clam juveniles to various parts of the Philippines in efforts to save and enhance the stocks of this endangered species. As a recipient of the UP-MSI Giant Clam Stock Enhancement Program in 2001, DNSC in collaboration with UP MSI has successfully protected 5 species of endangered giant clams and other marine species, making the Marine Reserved Park a home of more than 3,000 giant clams. It is identified as one of the learning and tourist sites in the Island Garden City of Samal (Igacos).

DNSC Marine Reserve Park. (Photo by Jojie Alcantara)

The DNSC, LGU-Igacos and BLGU-Adecor jointly pool resources for a conservation and livelihood project for Adecor United Fisherfolk Organization (ADuFOr). The project aims to promote the outcome of a marine protected area (MPA) in the conservation of endangered species and enhance the income of local communities through advocacy, tourism and community participation. The farming of giant clams is foreseen as means of promoting biological sustainability and maintaining biodiversity.

Four species of giant clams, Tridacna gigas, T. squamosa, T. derasa and H. hippopus were transplanted in the 14-Hectare Marine Reserve in Barangay Adecor, Kaputian District of Samal Island, one among the program's successful sites. The site is a marine protected area recovering from illegal and overfishing practices. The DNSC Marine Reserve Park has now become part of the tourism package of Visit Samal Tours.

Tridacna Eco-Tours had a grand launch on February 2013 (after a MOA was signed on Tridacna Tours Project in July 18, 2012, funded by Ched amounting to P1.3 million).

The tourism entrance fee of P75 excluding boat fare shall be used to sustain the project and offer income to key players, AdUFOr and Fisherfolk tour guides; as well as development fund to supporting institutions, DNSC, LGU-IGaCoS and BLGU-Adecor. The project demonstrates the benefits from marine protected areas that provide equity for both environmental protection and socio-economic development.

Now thriving at a depth of about 15 to 20 feet, these fascinating creatures have a lot to teach us. Giant clams are restricted to shallow, well-illuminated waters of coral reefs. They require clean, clear water of oceanic salinity. There is an increasing interest in these endangered species among local and international tourists because only a number of them are found in the wild. I have only seen these clams up close in Dinagat Islands and in Palau's Clam City back in 2006. In Samal, it was fascinating to see rows of them all lined up like a cabbage patch garden underwater.

Last April, 30 tourists from Asean nations toured the Tridacna Sanctuary as part of the tour of participants in the Asean Climate Change and Tourism Protocol Development Workshop held in Davao City. Dr. Girley S. Gumanao, Research Director, personally gave an orientation while locals of Adecor provided tour guiding, and LGU-Igacos provided boats.

I have read that giant clams play an important role in the ecology of the reef. Clam seeding is good for the marine ecosystem, and reseeding activities provide an upsurge in fish density and biodiversity in seeding sites, even before the clams have reached sexual maturity. Interestingly, clams become male mature at the age of eight years and become female mature by 10. At which time they become hermaphrodites, producing both female eggs and male sperms.

Mass spawning of clams releases millions of eggs and sperm in the waters, triggering a feeding frenzy and providing nourishment to thousands of tiny fish and organisms in a reef area, thereby attracting bigger fishes that seek clam meat. Studies and experiments reveal that putting both live and dead clam shells in the reef also entice fishes. With the shell being organic, fish, algae and other organisms will attach to it and take residence, a more effective reef enhancement technique than materials used for artificial reefs. Small fish, shrimps, snails, nudibranchs, sea slugs and urchins are known to be grazing on the outer shells. This contribution to a healthy reef ecosystem has great implications to our country's fisheries and food security.

Be warned, however. In the Republic Act 8550 of the Philippine Fisheries Code, Section 97 states the Fishing or Taking of Rare, Threatened or Endangered Species, that "it shall be unlawful to fish or take rare, threatened or endangered species as listed in the CITES and as determined by the Department. Violation of the provision of this section shall be punished by imprisonment of twelve years to twenty years and/or a fine of one hundred and twenty thousand pesos (P120,000.00) and forfeiture of the catch, and the cancellation of fishing permit."

Thank you DOT 11 for the tour as we jumped off from Punta del Sol Resort to a 10-minute boat ride to the marine park. Several of our media companions opted to go snorkeling and swimming on the shallow, cool waters.

By the way, my title says “Tripping with Tridacna”, not tripping over them.


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