Abstract:
Bataan is coastal province in the Philippines. It is connected to several other coastal areas of the country such as the Manila Bay. Morong, one of the municipalities in Bataan, is home to a large variety of flora and fauna however; very few studies have been done on the diversity of the marine life. In this study, a survey was done on the intertidal region of Nagbalayong Beach in Morong to determine the diversity of mollusks in the beach. A 100-meter transect was laid down on the shoreline of the beach to mark the sampling areas. The high, middle and low intertidal zones were sampled using a 1x1 meter quadrat. Thirty-five species of mollusks were identified in the beach. Through the use of various diversity indices, it was found that Nagbalayong Beach has an average diversity value of 1.63 for the high intertidal zone, 1.83 for the mid intertidal zone, 1.95 for the low intertidal zone and 1.523 for the area 20 meters beyond the low intertidal zone based on the Shannon-Wiener index. The most dominant species in the area were Siphonaria javanica from the family Siphonariidae. Horizontal zonation of species was affected by the type of substrate and abundance of marine vegetation while only substrate type and height affects vertical zonation. Ecologically significant species that may be used as indicators of the health of the beach such as, Atrina pectinata, Circe scripta and Angaria delphinus were also found in the intertidal zone.
