Trace metals in the marine surface microlayer of coastal areas in the Aegean sea, Eastern Mediterranean. (30th September 2021) - Karavoltsos, Sotirios
Abstract: Concentrations of 10 trace metals were determined seasonally in the sea surface microlayer (SML) and sub-surface water (SSW) at coastal areas of the Aegean sea comprising different morphological characteristics and degrees of pollution. Metal concentrations varied broadly, specifically in the SML, being typical of coastal areas subject to intense anthropogenic pressures. The mean enrichment factors (EFs) for dissolved metals range from 1.7 (for V) to 3.6 (Zn), being lower than the corresponding calculated for suspended particulate metals ranging from 2.4 (Cd) to 17 (Cr). A statistically significant enrichment of the SML (greater than unity) was obtained for dissolved metals following the decreasing order Ζn, Cu, Mn, Pb, Fe, Co, Cr, Ni, however not for Cd and V, and in the suspended particulate matter for Cr, Cu, Pb, Ni, V, Zn, Cd, Mn, while not for Fe. Surface microlayer enrichment in metals is governed by complex physicochemical and biological processes, occurring in coastal areas, among which the continuous precipitation of atmospheric particles onto the sea surface and the processes of metals dissolution and partitioning. Correlations among the trace metals examined, the sites sampled and the factor of seasonality are also discussed. Highlights: Trace metals were assessed in the sea-surface microlayer (SML) of coastal areas Ranges of metal EFs in SML (dissolved: 1.7–3.6; suspended particulate 2.4–17) SML was enriched in dissolved Zn, Cu, Mn, Pb, Fe, Co, Cr, Ni while not in Cd, V Air particles precipitation and metals dissociation seem to affect SML enrichment Correlations between metals, areas and seasons are also discussed