Trace metal variability, background levels and pollution status assessment in line with the water framework and Marine Strategy Framework EU Directives in the waters of a heavily impacted Mediterranean Gulf

The aim of this work is to assess trace metal pollution status (Cd, Cu, Ni, Pb, Zn) in the waters of Saronikos Gulf, Greece, in line with the WFD and MSFD European Directives, based on data collected over a decade (2000–2010). Dissolved metal background levels are estimated for the first time for Greek marine waters and the upper limits are: Cd: 0.574 nmol L−1; Cu: 8.26 nmol L−1; Ni: 7.94 nmol L−1; Pb: 2.60 nmol L−1; Zn: 115 nmol L−1. The variability of dissolved and particulate metals reflected the presence of several point sources and revealed the importance of natural mechanisms acting as non-point sources. The status of Saronikos Gulf is classified as ‘High’ for most metals studied. An exception to this is the enclosed Elefsis Bay where Cu, Ni and Zn concentrations are found above background. Our work will assist the implementation of WFD and MSFD directives in Greece.