Biological assessment of river cheshmekileh tonekabon (mazandaran) with use biological indicators, population structure and biomaa of large invertebrates macrobrnthic

Cheshmekile River in the southem Caspian Sea is an important and valuable habitat for migrating species and birth collect valuable fisheries such as salmon trutta caspius and Rutilus frisii kutuIn. In the present study, to assess the quality of river water Cheshmekile Tonekabon in the year 1389-1390 based on macroinvertebrates Fauna River in mounth studies at four stations within twelve sampling intervals with surber level 0.1m2 and three replicate were performed. Samples collect and fixed with formaldehyde %4, in laboratory have carried sort and enumeration. The study of 47 families belonging to 15 order and six category macroinvertebrate in the River was identified. Indicator of biodiversity in the River is among the highest diversity of aquatic insect larvae simultaneous sampling benthic. Result showed the Order Diptera, Ephemeroptera and Trichoptera that at station 1,2 and Order Diptera, Ephemeroptera and Oligochaeta class (Tubificida, Lumbricida, Lumbriculida and Haplotaxida order) were dominant. Survey Results showed that station 1 with the highest rate of 9.07 gm2 benthos biomasses and station 4 with the average weight of 1.11 g.m2 of the lowest levels allocated of total benthos biomass. Maximum abundance of organisms at this time to station 1 with 44% and minimum of 16% were related to the station 4. kruskal wallis test benthos invertebrates index Order Plecoptera, Trichoptera, Ephemeroptera, Orther stations throughout the year indicates a significant difference is between the confidence level of 95%(p<0.05) but the family Chironomidae at four stations during the year showed no significant differences between stations. Margalef and Shannon Wiener diversity indices of biological highestto lowest scores belonged to station 1 and station 4 is assigned. Shannon wiener diversity index, the diversity of macro benthos in the four stations very slight and small.