The Environmental Study on Evaluation of Water Quality at Prafi River, Manokwari, West Papua Using Macrozoobenthos Biotics Index and Physicochemical of Water Parameters

Globally, pollution of rivers and streams has become one of the most crucial environmental problems of the 20th century. This study aimed to determine the water quality along the Prafi River at Manokwari, West Papua, using some macrozoobenthic biotic index and chemical physics of water parameters. The location grouping was done using cluster and biplot analysis based on a macrozoobenthic biotic index and water chemical physics. Sampling was done based on the Purposive Random Sampling method in different part of river, such as upper (no human activities), plantation, dam, irrigation and fisheries, oil palm plantation, domestic, agriculture and livestock, and fishing area. In all locations, the results showed that the pH ranged from 7.80—8.36 and biochemical oxygen demand (BOD) from 0.53—5.51 mg/L. Prafi river was dominated by high activities of human and had an impact on poor water quality based on macrozoobenthos biotic index (Family and Hilsenhoff, respectively) but taxa score (ASPT) showed lightly polluted. Based on cluster and biplot analysis, half more of Prafi River was also dominated by polluted water in downstream site. Biologically, the polluted water could be identified by high percentage of Chironomidae around the river.