Investigating sand and gravel factory hogwash on biological, environmental and ecological indices in Tirom River (Mazandaran Province)

The research aims at investigating the effect of sand and gravel factory hogwash on biological، environmental and ecological indices in Tirom River. Examining the biological indexes was being done during 6 months، from July to November 2012 in 5 fishery farms through using Sorber، a sample collector in three reiterations. To measure environmental indices in water، there were examined 6 factors (pH، electrical conductivity، turbidity، TSS، TDS and water temperature) in research center of cold water fish، in Dohezar، Tonekabon. Moreover to measure the ecological indices to assign diversity، species dominance and richness، there were used Shannon-Weaver، Simpsons and Margalof. To analyze the data، after imposing standardization، there were picked up Kolmogrof-smirnof، One-way variance test، ANOVA، Besides to compare means، Duncan was utilized. Totally there were recognized 1727 Macrobenthos which they all belonged to 23 families and 7 orders. The most abundant was Hydropsychidae family and the least was recorded for Echyonuridae. The results revealed that the amount of suspension materials of TSS، solution material of TDS، as well as turbidity in three stands (the hogwash factory entrance) were highest to all other stands (P).