Seasonal trends and tissue distribution of organochlorine pollutants in wild and farmed gilthead sea bream (Sparus aurata) from the Western Mediterranean Sea and their relationship with environmental and biological factors.

Seasonal trends and tissue distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in gilthead sea bream (Sparus aurata) samples from the Western Mediterranean were investigated. Hexane extracts of white and red muscle, liver, and gills from wild and cultured specimens were purified by normal-phase high-performance liquid chromatography, and selected OCPs and PCBs were determined by gas chromatography coupled to mass spectrometry as indicators of contamination. The limits of detection for the analytical methodology allowed was 0.25 ng/g. Data obtained showed the presence of DDTs and PCBs in the different tissues, with the highest concentration of pollutants being in tissues of higher lipid content. Concentrations of organochlorine compounds in sea bream tissues strongly correlated with seasonal changes and the biological cycle of the species. In general, cultured fish had lower concentrations of contaminants and smaller season variability than wild fish. Trace levels of contaminants were found in fish muscle throughout the year, but always below the guidelines recommended for human consumption.