Density and diversity of the macrobenthic invertebrates in Pupot River, Tanay, Rizal

This study assessed the density, diversity, and relative abundance of the macrobenthic invertebrate communities of Pupot River in Tanay, Rizal. The physico-chemical characteristics of the river were also determined and correlated with the macrobenthic population of the area.Results of the study showed that the density, diversity and relative abundance of the macrobenthic invertebrates in the five stations differed. Density and diversity were highest where sediment concentration of water was low and dissolved oxygen concentration was high. Density and diversity were lowest in areas where sediment concentration was high and dissolved oxygen concentration was low. Gastropods were the most tolerant to the physico-chemical change in water quality of the river.Based on the proposed interpretation of diversity index values (H) by Wihlm and Dorris (1968) revealed that the sections of Pupot River that are approximately 100 meters upstream (i.e. station 1) and 3,000 meters downstream (i.e. station 5) from a cement factory outfall are either moderately polluted or clean waters. The sections which are approximately within 1,000 meters downstream (i.e stations 2, 3 & 4) from the cement factory outfall ranged from being moderately to heavily polluted waters