Assessment of Reef Fish Community Structure of Carenahan Fish Sanctuary, Balayan, Batangas.

Abstract

This study assessed the community structure of reef fishes in small, community-based fish sanctuary in Barangay Carenahan, Balayan, Batangas, in terms of abundance, density, species diversity and evenness, biomass and potential yield to determine the status of the sanctuary three years after its establishment. Results of the study were compared with previous studies done in the area to discern changes in the community that may suggest success or failure of the management strategies and actions applied in the area. Two other sites with potential for protection were likewise assessed using the same parameters used in Barangay Carenahan. One is located in NPC jetty and was previously reported to have high potential to be set as a reserve. The other one is being proposed by the locals as a marine reserve in Barangay Palicpican. Underwater fish visual census was done in three transect sites in the Carenahan sanctuary, two transect sites in NPC jetty and one transect site in Barangay Palicpican using scuba. Result of the survey in the Carenahan sanctuary yielded a total of 930 individuals, 70 reef fish species belonging to 24 reef fish families. For Palicpican and NPC jetty, a total of 163 individuals belonging to 22 species and 13 families and 856 individuals belonging to 76 species and 24 families, respectively were recorded. The biomass estimates of fish species in Carenahan, Palicpican and NPC jetty were 18.7, 67.5 and 22.6 g/m2, respectively. Among the three sites, Palicpican had the highest potential yield value of 0.10 tons/km2/year while Carenahan and NPC jetty both had 0.03 tons/km2/year potential yield value. Of the three reef fish categories, target fish species had biomass estimates of 12 g/m2 representing 47 percent of the total average biomass of fish in the three sites. Shannon-Wiener Diversity index value for the Carenahan sanctuary and NPC jetty was 1.4 while palicpican had only 0.95 which indicates high diversity in the two sites. This study observed an increase in species diversity, density and biomass for all three reef fish categories for all sites vis-avis NPC study conducted by Hilomen et al,. (2003). The reef fish assemblage in Carenahan sanctuary has improved after three years under official protection. The information generated in this study will form a baseline for the future from which to analyze the impact of the establishment of the fish sanctuary and marine reserve in the community.