A multibiomarker approach using the polychaete Arenicola marina to assess oil-contaminated sediments

Abstract

Marine and coastal sediments can accumulate substantial concentrations of metals and hydrocarbons, yet the consequences of this contamination for exposed biota in situ can be difficult to establish. Here, we examine the hypothesis that exposure to contaminated sediments can lead to detrimental effects in sediment-dwelling species. The combination of chemical and biological assessment allows the identification of the impact of chemical contamination, and their use as assessment tools is becoming increasingly important. The study was applied to marine sediments from the Bay of Algeciras (S Spain) impacted by multiple, low-level contaminant inputs, and the Galician Coast (NW Spain), historically impacted by an oil spill (Prestige 2002), with two reference sites selected in UK and Spain. The common lugworm Arenicola marina was exposed in the laboratory for 14 days to the marine sediments, and a suite of biomarkers of sublethal toxicity was combined with analytical chemistry to test for relationships between sediment contamination and effect. Moderate to strong correlations between organics, metals, and biological responses were observed, with DNA damage as measured using the Comet assay forming the largest contribution toward the observed differences (p < 0.05). The responses of worms from sites experiencing different contamination loads were clearly distinguishable. We show how a combination of multibiomarkers with analytical chemistry can be used to investigate the toxicity of marine sediments, enabling the differentiation of sites showing different types of contamination. There are clear relationships in sublethal assays that can be related to the putative mode of toxicity of the contaminants. The use of A. marina in this way provides a sensitive, holistic approach to sediment toxicity assessment, enabling comparisons between oil-polluted sites to be quantified. These tools provide a relatively simple, rapid, and economic way to test the environmental status of oil-contaminated sediment.