In line with the Subic Bay Metropolitan Authority’s mandate to conserve and protect the Freeport environment, the economic development should be in harmony with nature. As indicator species, presence of giant clams in the bay waters indicates good water quality, hence seeding giant clams will passively monitor Subic Bay and at the same time contribute to its biodiversity. Besides, giant clam seeding is the fastest and easiest method to repopulate the reef.

Giant clams (Tridacna gigas) are self sustaining with their mantle full of blown symbiotic algae which provides them food. They are also hermaphrodites (both male and female) and at certain age of maturity from 8-10 years, they spawn millions of sperms and eggs into the reef. Their sperms and eggs are fish food which will eventually attract a number of fish in the area.


  • To conserve the marine biodiversity of Subic Bay
  • To encourage stakeholders participation and involvement in environmental action and management activities
  • To increase the public awareness in giant clam and marine resources ecological importance


  1. Giant Clam Seeding Guidelines

    Participants should be in group and are member of the Subic Bay Freeport Locator or community’s stakeholders. Each member of the group must be at least 18 years old. Each group shall adopt at least 10 pieces of giant clams equivalent to 1 cohort and be seeded in site designated by the Ecology Center. At least 5 cohorts should be seeded at the same time in compliance to the requirements of the UP Marine Science Institute (MSI). The giant clams will be provided through the UP MSI, in coordination with the Ecology Center.

    The participant will be oriented and trained by the Ecology Center staff on how to conduct the re-seeding activity. Each participant shall bring their own diving/snorkeling tools for the activity. Seeding activity shall be facilitated by the SBMA Harbor Patrol and Ecology Center.
    Markers, logos or tags indicating the group name, number of clams planted and date will be installed in the area, they can have the option of holding ceremonies during or prior to the activity.

    Adoption period is for 5 years or until the giant clams are sustaining, hence monitoring of the giant clams will be conducted periodically. The adopting group can designate a maintenance crew for the areas and will be given proper training on giant-clam farm maintenance by the Ecology Center. Semi-annual reports should be submitted to the Ecology Center to assess the progress of the project.

    Each participating group will receive a Plaque of Recognition and shall be included in the publication of SBMA.

    In cases when stakeholders and group who are willing to adopt but unable to dive, the Ecology Center will facilitate the adopters to established partnership with local dive shops to assist them in monitoring and seeding activity.

  2. Site Selection and Procurement

    The Ecology Center Staff together with the Philippines National Museum, Zoological Division will determine the specific site for the giant clam seeding activity, in consideration of accessibility to the adopters, secured areas and biologically and physically acceptable for the survival of the clams.

  3. Procurement

    Since the UP MSI, Bolinao Marine Laboratory supplies the cultured clams for seeding, quotations for procurement of clams should be done at least one (1) month before the activity to determine what sizes and species of clams are available. Final quotation will be sent to the adopters for payment.

    Payment to UP MSI through the Marine Ecosystems and Resources Foundation (MERF) at the UP Diliman Campus must be done at least 3 weeks prior to the activity. The official receipt shall be provided after seven (7) working days.

  4. Pick-up of Giant Clams from Bolinao to Subic

    The giant clam will be procured from the UP Marine Science Institutes in Bolinao Pangasinan, The SBMA Maintenance and Transportation Department shall provide the truck for the transport of giant clams. Before and after transport, the Giant Clams need to get used to it new environment ro prevent them from stressing out and dying.

    They will be shipped in large Styrofoam containers / boxes filled with iced sea water, then placed on shallow waters overnight. The next day, each clams varying from young small ones aged 2 years old and large about 4 years old will be measured and tagged