Biodiversity boosts ecosystems stability and production. Therefore preservationof biodiversity is vital to natural ecosystems conservation including, freshwaterenvironments. The first step in which has to be taken into the account towardsbiodiversity conservation is; recognition of existing biodiversity in eachecosystem and determining the habitat suitability criteria for each individualtaxon to implement the ecologically-based management. Nowadays, using achosen groups of organisms as a biological index in environmental qualityassessment has received too much attentions
