Cd, Co, Cu, Ni, Pb, Zn in coastal and transitional waters of Greece and assessment of background concentrations: Results from 6 years implementation of the Water Framework Directive

Abstract

Dissolved trace metal concentrations were determined in coastal and transitional waters during 6 years (2012 to 2015, 2018, 2019) of monitoring for the implementation of the EU Water Framework Directive (WFD) in Greece. In this work we provide an assessment of background concentrations for dissolved metals in saline water bodies at 3 geochemical-climatic zones of Greece and estimate the upper background concentrations (BAC) for each zone (z1, z2, z3), as follows: z1: 0.022 μg L−1, z2: 0.018 μg L−1, z3: 0.016 μg L−1 for Cd; z1: 0.072 μg L−1, z2: 0.081 μg L−1, z3: 0.057 μg L−1 for Co; z1: 0.420 μg L−1, z2: 0.591 μg L−1, z3: 0.531 μg L−1 for Cu; z1: 0.808 μg L−1, z2: 0.928 μg L−1, z3: 0.841 μg L−1 for Ni; z1: 0.415 μg L−1, z2: 0.383 μg L−1, z3: 0.421 μg L−1 for Pb; z1: 3.19 μg L−1, z2: 3.59 μg L−1, z3: 3.01 μg L−1 for Zn. Coastal and transitional water bodies are classified in relation to the BAC of each zone revealing a diminishing order Ni > Cu > Pb > Co > Cd > Zn for metals concentrations >BAC, showing clearly that Ni and Cu contamination affects the highest number of water bodies. Overall, transitional water bodies of estuaries and wetlands of high biodiversity were found more affected by metal contamination than coastal water bodies. Our work contributes to the assessment of background concentrations for metals and the development of Environmental Quality Standards (EQS) on the EU, regional or individual country level. Specifically, for Greece, it provides the first dataset towards this direction, and highlights Cu as a priority metal. Thus, our work contributes to the implementation of both the WFD and the Marine Strategy Framework Directive (MSFD).