Qualifying the Inlet Rivers of the Anzali Lagoon Based on Macro invertebrates Communities

The macro invertebrate and physico-chemical characteristics on 21 sites (upstream, downstream and around cities) of 12 rivers discharging into Anzali wetland were assessed. Margalef and Menhinic richness, Shannon and Simpson Diversity indices, EPT/Chir and Hilsenhof family level biological index were calculated for each study site. The sites located near the populated city Rasht showed the least diversity and richness indices and the upstream demonstrate the highest values during the whole survey period. Based on Hilsenhof biotic index, stations near the urban area and just before entering the wetland had a poor to very poor water quality, indicating high organic enrichment in these regions. Only a few upstream stations were classified as "good" water quality (4.5>HBI>5). High phosphorous and nitrogen of water confirmed the observed classification. This result reveals the role of urban and agricultural activities in increasing organic pollution of the Inlet Rivers can accelerate the eutriphication of Anzali wetland. According to the study, there is an urgent need for well developed technologies and managements to reduce the organic pollution and its environmental impacts on the Anzali Lagoon.