Application of the Shore Zone Functionality Index to the Mantua lakes (Italy) and its comparison with two biological quality indices.

The Shore zone Functionality Index (SFI), proposed by the Italian Institute for Environmental Protection and Research (ISPRA) in 2009, assesses the quality of lake surrounding areas complying with the Water Framework Directive (WFD 2000/60/CE). The method evaluates the functionality of lake surrounding areas providing a useful instrument for land planning and management. In this study, the SFI has been applied to three lakes near the city of Mantua (Lombardia, North Italy) and compared with two other indices: a diatomic eutrophication/pollution index and a biological quality index based on macroinvertebrates. The comparison was carried out in order to verify the connection between the quality of lake surrounding areas and the biological quality of the lake’s water body. The application of the method showed very heterogeneous SFI index values along the shore zone of the three lakes: differences in type and abundance of vegetation and land use have led to judgments of functionality ranging from excellent to extremely poor. No correlations were found between the two indices and the SFI demonstrating that the quality of the shore zone of a lake is not necessary connected with the biological quality of the water body. The SFI index appears very promising to assess functional levels of the surrounding areas of lakes, however the method should be always associated with other indices that evaluate the biological quality of the water body in order to provide a wide knowledge to the land planners and managers.