Eels: contaminant cocktails pinpointing environmental contamination

river basins of IJzer, Scheldt, and Meuse (ca. 13 500 km 2 ), 2613 eels were sampled covering a dense monitoring network of 357 stations. Eels were analysed for ca. 100 chemicals. These included PCBs, organochlorine pesticides, heavy metals, brominated flame retardants, volatile organic pollutants (VOCs), endocrine disruptors, dioxins, perfluorooctane sulphonic acids (PFOSs), metallothioneins, and polycyclic aromatic compounds. This series represents only a very small fraction (,0.5%) of the .30 000 chemicals currently marketed and used in Europe. The biomonitoring value of eels as a tool for monitoring environmental contamination is illustrated. Two major conclusions were drawn: (i) the eel is a highly suitable biomonitor for environmental contaminants, for both local and international purposes, e.g. to evaluate the chemical status for the Water Framework Directive, and (ii) dependent on the degree of pollution in their habitat, the levels of certain contaminants reported in yellow eels can be high, and might affect their potential for reproduction.