Assessment of the environmental status in the Hellenic coastal waters (Eastern Mediterranean): From the Water Framework Directive to the Marine Strategy Framework Directive

Abstract

A tested methodology is presented to assess the environmental status Sensu on the Marine Strategy Framework Directive (MSFD) based on the data obtained from the monitoring of water quality in the Hellenic coastal waters within the Water Framework Directive (WFD). A decision tree developed by Borja et al. (2004) for integrating WFD results was applied after some adaptations. Modifications were included to evaluate the physicochemical status based on the eutrophication index developed for the Eastern Mediterranean waters. Results regarding the hydromorphological, physicochemical and biological elements are presented. The chemical status was assessed based on the concentrations of the heavy metals in water. Evaluation of the biological quality was based on the use of metrics developed for the phytoplankton biomass, benthic macroinvertebrates and macroalgae updated to accommodate the MSFD needs. Results from the integrative status of the water bodies were validated by correlating the classification results with a pressure index and environmental indicators in the water column and sediment. Following this decision tree the majority of stations expected to be at risk for achieving the 'good' status were found in the 'moderate' status. The benthos was found to be the element showing the closest agreement with the integrated final status having an increased weightage in the decision tree. The benthos quality and, in some limited cases, the eutrophication index largely determined the final status. The highest disagreement with the integrative classification was revealed by the macroalgae. All the indicators used correlated with the water and sediment parameters, although the benthos correlated better with the sediment factors while the phytoplankton and eutrophication index correlated with the water column parameters.