3.     Ecological status and potential

3.1.    Introduction

Water Framework Directive (WFD) defines “Ecological status” as the quality of the structure and functioning of aquatic ecosystems associated with surface waters.  Ecological status results from assessment of the biological status of all WFD biological quality elements (fish, macroinvertebrates, phytoplankton, phytobenthos, macrophytes) and the supportive physico-chemical parameters (general and specific ones).  According to ecological status water bodies can be classified into five categories, such as high, good, moderate, poor and bad.