Mercury in the coastal waters of Greece under the implementation of the Water Framework Directive (WFD)

Mercury (Hg) is an environmentally hazardous metal and a priority element in Mediterranean environmental monitoring. Hg is a priority pollutant in the main pieces of European legislation pertaining to the marine environment (the Marine Strategy Framework Directive - MSFD and the Water Framework Directive WFD). Despite the environmental importance of Hg there is limited knowledge on levels in Greek waters. The Laboratory of Environmental Chemistry (LEC) analyses very low Hg concentrations (above 0.5ng/L) using state of the art equipment in clean room facilities and participates in the national WFD coastal zone monitoring since 2012 in collaboration with the Hellenic Centre for Marine Research (HCMR). This paper presents the first attempt to evaluate Hg levels in the coastal waters of Greece in the last 8 years (2012-2020) and identify trends and spatial patterns. The Hg levels measured in all areas were well below the European Legislation threshold of 70ng/L (EC 2013/39). Increased levels of Hg were found, as expected, near the major cities of Greece (Athens, Thessaloniki) and the major rivers of Northern Greece as well as in some of smaller ports.