Coral reef resources
in the Spratlys

It is important that a summary Philippine report on the biological resources be made at this time because of the shift of the JOMSRE program to another phase beginning this year with the participation of the third country, China. As Chief Scientist of JOMSRE-SCS III and IV, I am making this report for public consumption. The Marine Biology results are being prepared for publication within this year.

In this column, I give a summary of the main findings on the seagrasses algae, the corals, the reef fishes, the large invertebrates, and the fish plankton based mainly on the available data from the North Danger Reef, the Jackson Atoll, the Trident Shoal, and the marine waters separating these reef systems. The original sampling design of JOMSRE III and IV included the survey of two atolls and two shoals, but the weather conditions in April 2007 did not permit field sampling on the second shoal.

The coral reefs in the Spratlys are shoals and atolls with their associated sand cays and islands. Nowhere in the country can one find atolls of the kind found in the Spratlys. Coral reefs are either exposed to wave action or sheltered in lagoons of atolls, and some have developed on slopes or drop-offs, providing varied microhabitats for various marine species. Live coral cover is moderate to high with little evidence of blasting but with a moderate density of crown of thorns starfish. Data I 2007 indicate the presence of about 200 species of reef-building corals belonging to about 45 genera and 16 Families, and some of the species are probably new records.

The 2005 and 2007 expeditions failed to observe top carnivorous species such as sharks, dolphins and whales. There were no marine turtles and sea snakes even in lagoons where they were expected. No mangrove species were observed in the study areas.

Firmly documented were the sparse growth and patchy distribution of only three seagrass species, in contrast to the five species reported during the first JOMSRE. This discrepancy could be due to species misidentification. About 69 species of algae (seaweeds) were reported during the first JOMSRE in 1996, but about 84 algal taxa dominated by the reds (some of which could be new species) were identified in 2007. Algae and seagrasses were not abundant in the areas studied, and primary productivity in the Spratlys is assumed to be primarily due to phytoplankton.

Few giant clams and sea cucumbers were seen. Only four species of giant clams were observed in 2007. Five species of sea cucumbers were reported in 2005, but only two of these were seen in 2007. The reason is clearly over-harvesting. In 2005, groups of fishers from Palawan were reported collecting fishes, clams and sea cucumbers, and one of them was not allowed to harvest sea cucumbers and fish in the lagoon of the North Danger Reef.

The 1996 JOMSRE reported ca 200 species of fish in three reefs of the Spratlys other than the North Danger Reef. About 292 fish species were reported from the Kalayaan Group in 1998 and about 218 species from the North Danger Reef in the 2007 JOMSRE. These two reports also stated that the densities were low. The 2005 JOMSRE report showed small sizes of fish (juveniles), an indication that they may have come from other areas of the Spratlys. The 2007 JOMSRE initial report for the North Danger Reef and the Jackson Atoll was a total of 287 species distributed in 38 Families. The target (food) fishes in the North Danger Reef and Jackson Atoll (all unprotected reefs) had biomasses smaller than, or at most equal biomasses were much lower than those in Dauin (Negros Oriental) reefs protected for 10-20 years. The fish plankton survey in 2005 also showed that the reef-associated fish larvae caught in the vicinity of the North Danger Reef were absent in the deeper waters between the Spratlys and the Philippines. The foregoing discussion suggests that because the current target fish biomasses in the Spratlys are low, they are most likely not sufficient to produce propagules (fish larvae) for western Philippine marine waters, contrary to the early suggestions of some marine biologists.