Development of a Fish-Based Multimetric Index for the Assessment of Lagoons' Ecological Quality in Northern Greece.

Maintaining and improving the aquatic ecosystems in the community is the aim of the Water Framework Directive (WFD) 2000/60/EC. The WFD requires the water quality to be classified into five categories. Lagoons are dynamic ecosystems. The fish communities inhabiting them are highly affected by the environmental conditions prevailing both in the freshwater systems and in the marine environment. The current paper presented the first effort to develop a fish-based index (Lagoon Fish-based Index—LFI) for the assessment of the Mediterranean shallow lagoons, as almost all indices produced to date refer to freshwater or estuarine systems. For the development and calibration of the index, data were collected from nine lagoons situated in three estuarine systems in the East Macedonia and Thrace regions. The development of the LFI was based on the principles of the Indices of Biological Integrity (IBIs) that were primary used for the assessment of aquatic ecosystems in the USA. A total number of 25 metrics were selected as potential metrics for the LFI. These metrics describe attributes such as the abundance and composition of the fish fauna, the feeding strategies of the species, and the presence of sentinel species. Finally, eight metrics were included in the LFI. [ABSTRACT FROM AUTHOR]