Benthic macroinvertebrate as biological indicator for water quality in Sungai Penchala

Sungai Penchala is one of the main tributaries for Sungai Klang which flows through the urban area of Wilayah Persekutuan Kuala Lumpur before merging with Sungai Klang in the Petaling Jaya district. As urban river, Sungai Penchala is polluted because of anthropogenic activities and this include direct garbage load, untreated drainage system from nearby residential area and also runoff from frequent heavy rain as the country located in tropical area. Currently, there are efforts from government and educational sectors to monitor and rehabilitate the river with vision to return it into its former natural function and not as a sink for urban population. Unlike pristine or recreational river, the water quality of urban river changes drastically over day even hours. Thus there is need for a procedure that can be used for water quality inspection in time of sampling but also provides reliable information that can resemble past event. Therefore, to do that the river monitoring was carried out by employing the traditional physical-chemical parameter by using Hydrolab Quanta® multi parameter reader. The benthic macroinvertebrate was collected using Surber's sampler and preserved in 95% ethanol for identification purposes. The data collected was analyzed for Water Quality Index (WQI) and Biological Monitoring Working Party (BMWP) to determine the river condition. The system used has its own strength and weakness but when employed together, it is expected to give better knowledge in evaluating river condition. Thus, increase the accuracy of evaluation process. In this study, the biological monitoring shows that changes in water quality influence the diversity of benthic macroinvertebrate. This study prove that biological monitoring by utilizing benthic macroinvertebrate can also be used in determining water quality of urban type river. It is also produced result that more readily interprets as it reveal past event disturbance which sometimes missed by physical-chemical parameters.