The survey biodiversity and abundance macro Invertebrates using bio indexe in Dohezar river- Tonkabon (Iran)

This study aims to explore, the Dohezar river biological diversity and abundance of Macro benthos using demographic indicators from October 2010- 0ctober 2011. Samples of macroinvertebrates were collected monthly from 7 stations designated as station 1 (upstream of the river course) to station 7 (downstream of the river course) for a period of 12 months. A combined total of 60 families and 18 orders and 7 class species of macroinvertebrates were encountered in the study. with the sampling of benthic fauna of some physic-chemical factors such as temperature, BOD5, DO, pH were also measured at the station in that the above factors does showed significant difference at the probable level of 5% (P<0.05) Except DO that does not showed significant difference at the above-mentioned stations. The fauna data surveyed with using MARGALEF and BMWP & ASPT biological index. One-sided variance analysis test of BMWP & ASPT index indicates existing a significant difference among the stations in probable level of 5 %( P<0.05). According to BMWP index, the highest mean belongs to station 2 with 119.8 score mean possibly due to minor contamination and the lowest score belongs to station 7 with 69.2 mean score which has the average level of organic contamination. The MARGALEF index does not showed significant difference at the stations in probable level of 5 %(P>0.05). The reason that was probably effects high flow velocity Dohezar River and high self-purification capacity that cased to effluent dilution and effects adverse less. This study showed influence different pulsation such as effluent fish farms or excessive removal sands of bottom river in the stations up river diversity and abundance between sensitive families macro benthic to pulsations showed less but don't sensitive families in down river showed increased such as (Naididae,Tubificidae,Chironomidae,Simulidae,Baetidae,Hydropsychidae).