Study of productivity potential based on diversity and frequency of benthos in Shamrood River

Shamrood river is one of the important river located in the north of Iran. In order to identify the benthic invertebrates of the river, a series of sampling were carried out during one year. The samples were collected by surber sampler (40×40 cm). In this study, the identified invertebrates were: Ephemeroptera 8 genus with the most biodiversity; Plecoptera 2 genus; Coleoptera 4 genus (larvae and pupa); Trichoptera 5 genus (larvae and pupa); Diptera 6 genus in forms of larvae and pupa with the most abundance; and also Hydracarina, Oligochaeta and Turbelaria. The frequency of different species of benthoses were the same in headwater stations and there were more genera diversity. On the other hand, in downwater stations (with lower slope substrate), the ferquency of some families and genera such as Chironomidae and Hydropschae increased but the genera diversity decreased. Based on biological index of benthic invertebrates and mean annual ferquency (26.1); the total production potential and mean total biomass were estimated 348 kg/ha and 4.15 g/m2, respectively