Abstract: Based on the integrated assessment methods of ecological quality status (EcoQS) in coastal waters abroad as well as the domestic related research status, 11 indices were selected from the biotic and physicochemical elements of water and sediment to built an integrated EcoQS assessment index system, and, with the comprehensive consideration of domestic and international evaluation standards, 5 levels of EcoQS classified as “high, good, moderate, poor, and bad” were determined. Then, an integrated assessment method of EcoQS in coastal waters was established by using analytic hierarchy process (AHP) and fuzzy mathematics method, and tested by the analysis of the correlations between the EcoQS grade and the major anthropogenic disturbances and pollutant concentrations of Tong’an Bay. The EcoQS of Tong’an Bay was assessed as moderate, i.e., the Bay was moderately disturbed and in transitional to poor status. The established integrated assessment method could not only reflect the major anthropogenic environmental pressure and risk factors, but also give an early warning of the pollutants satisfied by law in the study area.

Key words: coastal waters, ecological quality status (EcoQS), fuzzy integrated assessment, index system, Tong’an Bay