O. Rafieyan*1, A. A. Darvishsefat2, S. Babaii1, A. Mataji1
The distribution of macroinvertebrate communities from 5 sampling sites of the Tajan River were used to examine the relationship among physiochemical parameters with macroinvertebrate communities and also to assess ecological classification system as a tool for the management and conservation purposes. The amount of variation explained in macroinvertebrate taxa composition is within values reported in similar studies. Results of CCA ordination showed that the dissolved oxygen, water temperature, turbidity, pH and TSS were the most important physico- chemical factors to influence distribution of macroinvertebrate communities. The study revealed that macroinvertebrate communities of the Tajan River may be explained by physiochemical parameters. Mean values of Shannon?Wiener diversity index calculated for macroinvertebrates ranged from 1.35? 0.07 (S5) to 1.86? 0.10 (S1). According to the Shannon?Wiener diversity index the S1 sampling site was categorized in ??good?? and the sampling sites S2 and S3 in ??moderate?? and S5 in ??moderate to substantially polluted? classes. The anthropogenic disturbances (e.g. trout farms and effluents from factories) impacted abundance and diversity of macroinvertebrate.