Thesis (BS Biology) -- University of the Philippines Mindanao, 2000

This study aims to characterize the coral reef benthic communities in ten selected sites in Davao Gulf using the physiognomic-structural approach, indices of assessment and mortality index. Using the TWINSPAN analysis, the ten sites were characterized into four types of groups based on the presence or absence of lifeform indicators. The correspondence analysis allowed the identification of lifeforms that were closely related. The development condition, succession and mortality indices values were also obtained as influenced by monsoonal exposure, geographical location and silt accumulation which further enhanced the characterization of the coral benthic communities in Davao Gulf. Group A (composed of 1 site) is characterized by the predominance of dead corals, high development index, low condition, low succession in terms of other fauna, but high in terms of algal succession. This indicates that the reefs in these identified areas are in the recovery stage and are subjected to several stresses. Group B (composed of 4 sites) and C (composed of 3 sites) have almost similar composition, exposure, and succession. However, the mortality in C is higher. Generally, the reefs are in good condition. However, those sites with high mortality are threatened by several stresses. The two sites in group D are characterized by the abundance of Acropora indicating that these are high-wave energy areas. However, the condition and succession values are negative. This indicates that the reef areas cannot be considered as healthy for the normal growth and development of corals as well as the invasion and establishment of other fauna