ارزيابي زيستي رودخانه لاسم( شهرستان آمل -استان مازندران ) با استفاده از ساختار جمعيت بزرگ بي مهرگان كفزي

Bioassessment of Lasem River (Amol, Mazandaran Prov.), Using Macroinvertebrates Community Structure

Assemblage structure of benthic macroinvertebrates studied in Lasem river (Amol, Mazandaran Prov.) during 12 months, that they collected with surber sampler (40x40 cm, Mesh 100 Mm). 33 families and 32 genera identified from benthic macroinvertebrates that aquatic insect larvae (Ephemeroptera, Diptera, Trichoptera and Plecoptera) had most abundance and diversity. The maximum amd minimum abundance was 2411.9 No/M2 in station 2 and 725.5 No/M2 in station 1 respectively. Benthic macroinvertebrates Frequency data was summarized to community structure metrics including Total Richness, EPT Richness, EPT%, EPT/Chir and PCD. Hilsenhoff and BMWP/ASPT family level biotic index were also determined for each studied station. Minimum and maximum HFBI were 3.55 for station 1 and 4.25 for station 2 respectively. Maximum and minimum BMWP/ASPT index were 6.67 for station 3 and 5.72 for station 5 respectively. In end, stations was assayed quality condition. They classified in 3 groups that station 2 was bad quality and station 3 was good quality condition.