Assessment of water quality of Gamasiab River using BMWP and ASPT Indices

The rivers are under threat by numerous pollutions and their quality assessment is a need. Water quality of the Gamasiab River in Kermanshah Province was assessed using biological indices (BMWP and ASPT method). Six stations were selected and macro invertebrates were collected by surber sampler from July 2013 to May 2014. In this study, 11 families of the macro invertebrates from 10 orders were identified; Gammaridae، Lymnaeidae and Chironomidae were the most dominant, respectively.  After identifying and counting the macro invertebrates, ASPT and BMWP indices were calculated to determine the contamination of Gamasiab River. BMWP mean showed significant differences between all stations and stages (P < 0.05). Except for station 6 that was in very good class, the water quality of the Gamasiab River was classified as middle to bad condition. ASPT mean  showed significant differences between stations (P < 0.01) and classified the water quality of Gamasiab River in the category 4. According to the results, environmental and ecological characteristics of Gamasiab River are moderate.