Determination of water quality profile of an urban stream in Gediz River Basin (West Anatolia, Türkiye) and comparative analysis of biotic indices

Abstract

This study was carried out to determine water quality of the Kum Stream and to compare the performance of the Saprobe Index (SI), several modifications of Biological Monitoring Working Party (BMWP), several modifications of Average Score Per Taxon (ASPT), Belgian Biotic Index (BBI), Family Biotic Index (FBI), EPT-Taxa [%], Simpson’s (SDI), Shannon-Wiener (SWDI) and Margalef (MDI) diversity indices. Six sampling stations were determined and the samplings were carried out seasonally. Biotic and diversity indices based on benthic macroinvertebrates have been applied using Asterics software. Pearson’s based correlations were applied to the indices in order to determine the proper biotic indices. A total of 37 taxa which belong to Gastropoda, Oligochaeta, Crustacea and Insecta were detected. The dominant group of the benthic macroinvertebrates was Insecta with 26 taxa. According to the result of ANOSIM (Analysis of Similarity); no statistically significant difference was found between the seasonal distributions of the species (p = 0.267; R: 0.038). According to the MANOVA (Multivariate Analysis of Variance) result, the seasons didn’t show a significant difference on the linear combination with environmental variables (p = 0.138 > 0.05). According to the results of CCA (Canonical Correlation Analysis), it was determined that the groups known for their sensitivity to pollution showed a positive correlation with the DO and pH variables, while the groups with high tolerance levels and containing many species as pollution indicators showed a positive correlation with the temperature, TU and EC variables. As a result of this research, the water quality of the Kum Stream was determined as polluted. BBI, ASPT and BMWP indices were more proper than SI and FBI indices to determine the water quality of the Kum Stream.