Biliary PAH metabolites in European eel (Anguilla anguilla) from Mar Menor lagoon (SE Spain)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic contaminants present in marine sediments as a consequence of their continuous input from either land- or marine-based sources. Fishes have a higher capacity to metabolize and excrete PAHs than invertebrates such as mollusks and consequently the concentration of PAH metabolites in the bile fluid of fish can be used as an indirect indicator of exposure to PAH contamination. In this study the concentration and distribution of major PAHs metabolites in European eel (Anguilla anguilla) bile from the hypersaline Mar Menor coastal lagoon (SE Spain) were characterized for the first time. Eels of two different weight classes (350 g) were sampled from the northern and southern part of the lagoon using traditional fishing methods by local fishermen in spring 2014 and winter 2015. Bile samples were treated individually and maintained at -20ºC until analysis. 10 L of bile sample was diluted with water for liquid chromatography, incubated with β-glucuronidase/arylsulfatase for 2 hours at 37ºC, then the reaction was stopped with cold methanol and the sample centrifuged. The concentrations of PAHs metabolites (phenanthrol and pyrenol) in the supernatant were directly analysed by liquid chromatography with fluorescence detection using a standard solution for external calibration. Phenanthrol and pyrenol were found in all samples, with pyrenol being always the predominant one. The metabolite concentrations were higher in specimens sampled in spring 2014 than in winter 2015, suggesting a different seasonal pattern of PAH exposure to fish in the Mar Menor lagoon