Application of the EPT-index for Ecological Status Assessment of the Riverine Water Bodies within the Basin of Kamchia River

Indexes based on the intolerance of the groups Ephemeroptera, Plecoptera and Trichoptera to pollution were used for assessment of the ecological status along the river system of Kamchia. The achieved data about the EPT-indexes were compared with standard biological indexes for water quality assessment of the surface running waters, according to Ordinance No.7/1986 (Appendix 1). The results from the survey illustrated that the values of the ЕРТ-N and ЕРТ-S indexes confirm the assessment for the sapro-biological conditions along the Kamchia river valley. These indexes efficiently establish the changes in the water quality and successfully can be used for the purposes of ecological categorization of the river water bodies.