The Philippines forms an ocean region that has long been recognized as the world’s center of marine biodiversity. With the Malay archipelago, Papua New Guinea and Australia, the country forms the ‘Coral Triangle,’ so-called because of the abundance of its coral reef life. Some 400-500 species in 90 genera of reef-forming corals are believed to exist in this region. Sulu-Sulawesi Sea, a 900,000-square-kilometer marine eco-region that lies at the apex of the Coral Triangle (70% in the Philippines, 20% Indonesia, 10% Malaysia), is home to some 2,500 species of fish.
A 2005 report (Carpenter 2005) suggests that the Philippines is not only part of the center but is, in fact, the epicenter of marine biodiversity, with the richest concentration of marine life on the entire planet.
Center of the center
The report is based on a 10-year multi-disciplinary study conducted for the Food and Agriculture Organization (FAO) that involved 101 of world’s leading authorities on marine life, and produced 2,983 maps of marine species for the western Pacific Ocean. (ODU News 2005)
Kent Carpenter, Old Dominion University associate professor of biological sciences who headed the study, says, “Scientists have long known that the area in Southeast Asia that includes Indonesia, Malaysia and the Philippines holds the richest marine biodiversity. I was amazed to discover that the extreme center of this biodiversity is in the Philippines, rather than closer to the equator. However, a geographical information system (GIS) analysis of this extensive database clearly shows this pattern.” (ODU News 2005)
Carpenter and co-author Victor Springer of Smithsonian Institution’s National Museum of Natural History used a GIS overlay of 2,983 generalized distributions of marine species to examine the pattern of diversity in the Indo-Malay-Philippines Archipelago (IMPA). Their analysis revealed the central Philippines as “the area of highest diversity and endemism.” (Carpenter 2005)
The Philippine center of diversity was found to have the highest species richness for all distributions combined as well as when shore fish distributions were treated separately. (Carpenter 2005)
“Because of its greater area, Indonesia may eventually be shown to have a greater overall marine biodiversity than the Philippines. However, there is a higher concentration of species per unit area in the Philippines than anywhere in Indonesia,” the report says. (Carpenter 2005)
It also notes that of 120 restricted-range endemics included in the study, the Philippines has 38, compared to 19 in Indonesia/Malaysia, 18 in Australia, 18 in New Guinea/Bismark/Louisade, 17 in Coral Sea/New Caledonia/Vanuatu, and one or two in seven other localities. (Carpenter 2005)
The full extent of the Philippines’ marine biodiversity is not known, but the best information available reveals an astounding variety of marine life: 5,000 species of clams, snails and mollusks (Springsteen and Leobrera 1986); 488 species of corals (Nemenzo 1981); 981 species of bottom-living algae (Silva et al 1987), and thousands of other organisms. Five of the seven sea turtle species known to exist in the world today occur in Philippine waters.
The lists are likely to grow, as new surveys discover new species. In 1953, Herre recorded 1,815 marine fish species (out of a total of 2,145 fish species) in the Philippines; today, about 2,824 marine fish species are listed for the Philippines at FishBase (February 2006), including 33 endemic (one of which is endangered), 1,729 reef-associated, 169 pelagic, and 336 deepwater species.
In 2004, a survey in Panglao, Bohol observed 1,200 decapod crustaceans or different species of crabs and shrimps; some 6,000 mollusk species, including sea slugs and microshells; and hundreds of other previously unrecorded marine species.
The survey also found fossils of snails extinct in other parts of the world, and numerous species that were photographed alive for the first time.
Another survey was conducted in 2005 under the same project in the deep waters (up to 2,200 meters) of the Bohol-Mindanao-Cebu triangle. It recorded some 1,000 mollusk species, 600 crustacean species, more than 100 echinoderm species, and over 100 fish species, many of them considered rare or very rare, or new to science.
Such richness, according to experts, can be explained by geologic history: the isolation of smaller seas within the central Philippines in the Pleistocene ice ages, and complex geological events leading to the integration of islands that created the archipelago. (Carpenter 2005)
“The amalgamation process created barriers when the larger islands took shape and potentially separated populations and provided conditions for allopatric speciation,” Carpenter and Springer (2005) suggest. “The accretion of the archipelago would also have concentrated diversity, assuming that the different elements of the Philippines developed their own endemic biotas.”
Carpenter’s goal is to understand the natural forces, such as lithospheric plate movements, prevailing currents, and the geography and geology of the area that contributed to the evolution of the biodiversity.
“This discovery poses some very interesting questions about the origins of marine life in our oceans. Perhaps the Philippines hold the key to unraveling mysteries about how marine biodiversity patterns change through space and time,” Carpenter says.
“Biodiversity is of major interest to many people. Many marine organisms have yet to be looked at for pharmacological purposes. Some sharks appear resistant to cancer. It turns out that sharks are becoming endangered because of over-fishing. Some marine organism might hold the cure to cancer, but we are destroying them before we get a chance to study them.” (ODU News 2004)
A real threat of extinction
Indeed, the Philippine center of marine biodiversity is highly threatened by a host of factors ranging from destructive fishing practices to soil erosion and global warming. The comparatively high number of species found only in the Philippines indicates a real threat of extinction, including of species that have yet to be discovered by scientists.
Carpenter and Springer (2005) liken the Philippine seas to the Amazon, as rich in unique life and equally endangered.
“Understanding factors that control patterns of endemism and richness should …help prioritize sites for conservation even when data are sparse, as they are often in the marine environment,” they say. “Solely as an example of peak diversity and endemism, there is ample justification to prioritize the Philippines for conservation. As a probable epicenter of allopatric speciation and island integration bio-concentration, it is imperative to conserve the habitats and diversity that can help us to understand the processes that govern biodiversity in the marine realm.”
“Clearly, marine conservation efforts in the Philippines warrant special attention.”