Trophic state and water quality in Mediterranean coastal lagoons: Lesina vs Varano

The Water Framework Directive (WFD) establishes a framework for the protection of all waters (including inland surface waters, transitional waters and groundwater) in order to achieve good ecological status by the year 2015. The Directive requires definition of ecosystem typology and ecological status and the identification of type-specific descriptors of monitoring ecological status. Nevertheless, transitional water ecosystems are characterised by intense and sometimes unpredictable spatial and temporal variability in physical-chemical and biological conditions. This contribution highlights some of the main topics debate about WFD implementation comparing Lesina and Varano lagoons, situated on the southern Adriatic Sea coast (Italy), which are geographically adjacent therefore are influenced by the same meteorological forcing and tidal range. They are different in geomorphological features (0.7 m and 3 m mean depth for Lesina and Varano, respectively), salinity range, water residence time, nutrients loading. Physical-chemical parameters, nutrients and chlorophyll a concentrations, total and organic particulate matter have been used in order to assess ecological status. Several indexes have been used to classify the trophic state and water quality of Lesina and Varano lagoons.