Diversity Of Marine Macro Molluscan Gastropods and Bivalves In The Intertidal Areas Of Ajuy, Iloilo, Western Visayas, Philippines

Abstract

Abstract The Philippines has rich marine resources but are threatened by the effects of climate change and other activities made by humans. There is an inadequate or scarcity in literature on prominent impacts of climate change on the country’s rich biodiversity, specifically on marine ecosystem, thus this study aimed to determine the diversity of marine macro molluscan gastropods and bivalves on the intertidal areas of Ajuy, Iloilo, Western Visayas, Philippines. Marine macro gastropods and bivalves were surveyed monthly from October 2015 to March 2016 and transect method was carried out to assess species composition, abundance and occurrence. Shannon-Wiener index (H’) was utilized to determine the diversity of marine macro molluscan gastropods and bivalves in the area. Coefficient of correlation was used to determine correlation between physico-chemical properties of sea water with the diversity index value. There were a total of 8,705 individual mollusks sampled and classified up to 43 species of gastropods having 28 genera belonging to 20 families and 29 species of bivalves belonging to 22 genera out of 14 families. The family Muricidae was the best represented in species richness among the gastropods and family Veneridae among the bivalves. In family wise landing among the gastropods, the maximum number recorded was Batillariidae having a relative abundance of 46%. In bivalves, the most abundant family was Veneridae with 20.25% relative abundance. The Shannon-Wiener index value revealed that the area was still normal in terms of species diversity. Temperature and DO of sea water were positively correlated with the H’, whereas pH and salinity were negatively correlated. This study provided baseline information as to the status of marine macro molluscan gastropods and bivalves in the intertidal area of Ajuy, Iloilo, Western Visayas, Philippines.