Identifying fossil contamination from surface waters in native algae grown over floating artificial substrates

Abstract Environmental pollution with chemical inputs from chronic and punctuated spills can occur in aquatic environments and reflect a risk in maritime activities, induce detrimental ecological consequencesand affect human health. In this study, native green algae grown on artificial substrates and exposed to a pollution gradient in a eutrophic coastal estuary are investigated to assess fossil-derived contamination. A substantial proportion of the pollution in such environments originates from fossil fuel sources, which are devoid of radiocarbon ( Superscript 14 14 ${{\rm{\;}}^{14}}$ C). Therefore, radiocarbon analysis, together with n-alkane characterization, provides an excellent tracer for identifying fossil pollutants and assessing their magnitude and geographic distribution. Our findings highlight the ability of algae to accumulate n-alkane hydrocarbons under differing sites and growth stages, with radiocarbon analysis showing up to 49% of fossil carbon in algae, and the Total n-alkanes concentrations between 1.45 and 125.38 mu μ $\mu$ g.g Superscript negative 1 − 1 ${{\rm{\;}}^{ - 1}}$ DW, with a median of 6.9 mu μ $\mu$ g.g Superscript negative 1 − 1 ${{\rm{\;}}^{ - 1}}$ DW (N = 10). The sample with the lowest biogenic fraction was near a ferryboat station at Feb/2022, with a prominence of normal n minus normal upper C 27 n − C 27 ${\rm{n}} - {{\rm{C}}_{27}}$ (18.9