Evidencing the Impact of Coastal Contaminated Sediments on Mussels Through Pb Stable Isotopes Composition

Abstract

Heavily contaminated sediments are a serious concern for ecosystem quality, especially in coastal areas, where vulnerability is high due to intense anthropogenic pressure. Surface sediments (54 stations), 50 cm interface cores (five specific stations), river particles, coal and bulk Pb plate from past French Navy activities, seawater and mussels were collected in Toulon Bay (NW Mediterranean Sea). Lead content and Pb stable isotope composition have evidenced the direct impact of sediment pollution stock on both the water column quality and the living organisms, through the specific Pb isotopic signature in these considered compartments. The history of pollution events including past and present contaminant dispersion in Toulon Bay were also demonstrated by historical records of Pb content and Pb isotope ratios in sediment profiles. The sediment resuspension events, as simulated by batch experiments, could be a major factor contributing to the high Pb mobility in the considered ecosystem. A survey of Pb concentrations in surface seawater at 40 stations has revealed poor seawater quality, affecting both the dissolved fraction and suspended particles and points to marina/harbors as additional diffuse sources of dissolved Pb.

Remobilization of polycyclic aromatic hydrocarbons and organic matter in seawater during sediment resuspension experiments from a polluted coastal environment: Insights from Toulon Bay (France)

“…Several studies have reported high concentrations of trace metals, metalloids and organometallics during Toulon Bay seabed disturbances (Cossa et al, 2014;Dang et al, 2015a, Pougnet et al,2014Tessier et al,2011). In addition, Dang et al (2015b) demonstrated that Pb was significantly released in seawater and further transferred to organisms such as mussels during resuspension experiments on surface and deep sediments from Toulon Bay. Nevertheless, to our knowledge, no data are available describing PAH remobilization during sediment resuspension events in such a strongly dredged and multi-contaminated area.…”

“…Therefore, in the present study, we carried out supplementary experiments simulating the resuspension of surface and deep sediments in Toulon Bay, as proposed by Dang et al (2015b)…”

Precessional Cyclicity of Seawater Pb Isotopes in the Late Miocene Mediterranean

“…The very short residence time of Pb in the troposphere (less than a week; Moore et al, 1973;Turekian et al, 1977) leads to a near-instantaneous change in Mediterranean Sea Pb (Nicolas et al, 1994). Consequently, core top sediment Pb isotope compositions are not necessarily expected to reflect the composition of modern seawater (e.g., Alleman et al, 2000;Huy et al, 2015;Kamenov et al, 2009), and correspondingly, there is a paucity of information in the literature dealing with Pb isotope compositions in marginal Mediterranean sediment porewaters. However, in addition to these studies which indicate that Pb mobility is low, a few have shown results consistent with our assumption of substantial seawater control.…”

A Suite of Robust Radioanalytical Techniques for the Determination of Tritium and Other Volatile Radionuclides in Decommissioning Wastes and Environmental Matrices

“…In these situations, stable Pb isotope ratios provide an additional means of Pb source discrimination and have been applied successfully in a range of sedimentary/environmental settings (e.g. [27][28][29][30][31][32][33][34]). Ultrahigh precision, double-spike mass spectrometry stable Pb isotope data for the 2014 Hythe core (Figure 7) show a gradual reduction in 206 Pb/ 207 Pb ratio from core base upwards (consistent with studies from other sedimentary settings in the UK (e.g.…”