monitoring and assessment of water health quality in the haraz river,iran using macroinvertebrates indices

some macroinvertebrate indices of stream health have been identified as most useful and efficacious. management decisions can be made with greater awareness.the objectives of this study were to assess the biological water of the hazar river using macroinvertebrates.the haraz river is one of the best freshwater ecosystems in the mazandaran province located in the north of iran.to assess the macroinvertebrates diversity in the study area, simpson index was used,this parameter is 0.25 of the areathese include theept index the hbi is a index of stream organic. we identified 2 class, 3order , 16 families of macroinvertebrates. some sites of the case study were indicated to have a very bad condition.especially, the downstream sites are affected by indiscriminating mining for construction-grade sand from alluvial reaches is among the most disastrous one.diversity within the benthic macroinvertebrate community was described using the simpson’s diversity index.the biotic index was based on their tolerance to organic pollution , creating the family biotic index (fbi).in this survey, biotic index of haraz river was 5.72 which places in the rank of fairly substantial pollution likely this survey.