The effect of point source pollution (fish pond effluent) on macro-invertebrates communities and validation of three biotic indexes (EPT, BMWP, HFBI) in assessing the water quality of Baliglu river in Ardabil province

Document Type : (original research)


1 Faculty of natural science,Guilan, Someh Sara,Iran

2 Department of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran



In this study, the effect of fish pond effluent on water quality and validation of three common biotic indexes EPT, BMWPand HFBI in river was investigated. A sampling of invertebrates communities was done seasonally from the summer of 2018 for one year with the help of a Sorber sampling device with dimensions of (40 * 40 cm) and in three replications.10582 samples from 10 orders and 14 families were identified. The highest frequency was related to the order of Ephemeroptera and then Diptera, which belonged to the Baetidae and then Chironomidae family, respectively.Shannon-Wiener (H)(1.20) diversity, uniformity (exp (H) / S)(0.83), Simpson (1-D)(0.66), and dominance (D)(0.33) indices were used to study the diversity of macro-invertebrate communities. The results of determining the correlation of environmental parameters with the distribution of macrobenthos and environmental factors with each other by Detrended Correspondence Analysis (DCA) in PAST software (version 3.25) showed that the environmental parameters of nitrate and phosphate were positively correlated with Chironomidae and Tipulidae families. Based on the Helsinhoff(HFBI) biotic index, the water quality of the Baliqlu River in the third station with severe pollution (HFBI = 8.24), based on the EPT, water quality in the third station is poor (EPT = 9.5) and the BMWP biotic index reflects poor results.The validation results of the three indicators used, showing that the BMWP, unlike other indicators has a relatively poorer performance in the River and in the quality assessments of our country's rivers, it is better to use a combination of several biotic indexes.