Assessment of water quality in the Dehbar River using biological indicators

Biological indicators can be used as a useful and efficient method for assessing the quality of water. In most biomonitoring studies, benthic macroinvertebrates are considered due to extremely sensitive to environmental or anthropogenic pressures by changing in density and diversity. In this context, the aim of the present study was to determine the degree of contamination of the Dehbar River, (Khorasan Razavi) using the indices of HFBI, BMWP, ASPT, EPT / CHIR. Sampling was conducted from October and December 2016 at six sampling stations. A total of 736 macroinvertebrates belonging to 7 orders and 16 families were identified and the Baetidae family with 35 percent was the most frequent. The results of biological indicators indicated that the stations of 1, 2 and 3 were rated as moderate to bad, the stations of 4, 5 and 6 were rated as good to excellent. And also, the results showed that the downstream stations were influenced by human activities, while the more quality stations were located in upstream and they were influenced under less human disturbances. Overall, the study found that biological indicators can be a useful tool to monitor and assess the status of water quality of the Dehbar River.