menu.header.image.unacom.logo
 

11. University of the Philippines - Marine Science Institute (UP - MSI)

Permanent URI for this communityhttps://repository.unesco.gov.ph/handle/123456789/10

University of the Philippines - Marine Science Institute (UP - MSI) - Philippines - contributions to address the Ocean Decade Challenges

Browse

Filters

1988 - 198912020 - 20241

Settings

Geographic name: search.filters.geographicname.PalawanOcean Decade Challenge: search.filters.odc.Challenge 2: Protect and restore ecosystems and biodiversity

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Declining population of giant clams (Cardiidae:Tridacninae) in Palawan, Philippines
    Dolorosa, Roger G.; Mecha, Niño Jess Mar F.; Bano, Jemima D.; Ecube, Krizia Meryl A.; Villanueva, Elmer G.; Cabaitan, Patrick C. (FapUNIFESP (SciELO), 2024)
    For more than two decades, the Philippine government has protected the giant clams (Bivalvia: Cardiidae: Tridacninae) from exploitation and trade. However, there still is lack of information on the impact of these protective measures in conserving the species richness and density, especially in Palawan, the country’s last stronghold of these reef-associated bivalves. Hence, to assess the species richness and density of giant clams in Palawan, we conducted 57 photo-transect surveys in six sites covering 12,325 m 2. Out of these transect, 15 measured 5 × 25 m and the rest measured 5 × 50 m. For historical trends in the population of giant clams in Palawan, we used six published papers obtained from online platforms, 13 reports, and five undergraduate theses archived in local libraries. Information derived from recent field surveys indicated high variations in species richness (2 to 5 species) and densities (0.1 to > 3.6 ind.100 m -2). Historical data starting from 1984, including recent fieldwork, indicated very low densities and a declining trend. The current status suggests that giant clam populations’ viability and the reefs’ health are threatened. Effective mechanisms are needed to safeguard and enhance the remaining giant clam populations.
  • Thumbnail Image
    Fishing mortality rates of giant clams (Family Tridacnidae) from the Sulu Archipelago and Southern Palawan, Philippines
    Villanoy, Cesar L.; Juinio, Antoinette R.; Meñez, Lambert Anthony (Springer, 1988-05)
    Average size frequency distributions of Tridacna squamosa, T. gigas, Hippopus hippopus and H. porcellanus harvested from the Sulu Archipelago and Southern Palawan areas from 1978–1985 were derived from export records and a warehouse inventory of giant clam shells. Average species mortality rates (Z) were estimated and were used to approximate average fishing mortality rates (F) over the period 1978–1985. Crude estimates of exploitation rates (F/Z) indicate that populations of these species are already overexploited. These findings have serious implications in view of the fact that the Sulu Archipelago and Southern Palawan are thought to be the last strongholds of giant clams in Philippine waters.