Diversity and ecology of marine mollusks in Ticao Island, Masbate, Philippines: Implications for fisheries potential

Abstract

This study represents the first attempt to evaluate the ecological index and economic potential of marine bivalves and gastropods on Ticao Island, Masbate, Philippines. Two 2,000 m² sampling areas were plotted at two selected sites in the southern part of the island. Purposive sampling was applied during low tide over four consecutive days. Environmental parameters, including temperature, pH, salinity, and dissolved oxygen, were also recorded. The ecological index, including species richness, evenness, and diversity, were calculated for the gathered mollusk species. The potential economic value of these mollusks was analysed using references from published journals, books, and other sources. A total of 3,280 individuals of gastropods and bivalves were collected, representing 18 families, 39 genera, and 77 species for gastropods, and 4 families, 6 genera, and 15 species of bivalves. The species diversity index was 3.45 (very high), species dominance index was 1.02 (high), the species evenness index was 0.51 (relatively even), and species richness was 8.01 (high). Environmental factors were temperature (29.20- 30.70◦C), pH (7.94-8.45), salinity (36.01-37.90 ppt), and dissolved oxygen (6.54-16.67%). Of the total 92 mollusk species, 32 were edible, 16 were used in shell craft and trade, and 9 had biological, ecological, medicinal, or ethnozoological significance. These findings provide data essential for establishing the current status, sustainable management, and conservation efforts for mollusk species in the region, supporting potential developments in fisheries.