Effects of xenoestrogens in eels

Vitellogenin content in Euopean eel (Anguilla anguilla) in Flanders, Belgium

Context of the study

It's known that xenobiotic substances can have effects on the endocrine system of animals. These endocrine disrupting compounds can come from sewage treatment effluents. However little is known the effects of these compounds on fish in Flemish waters. Through it's carnivorous lifestyle the European eel accumulates many different chemicals throughout his life. During a certain phase of his life (the yellow eel phase) the eel doesn't migrate. Therefore, analysis of residues from eels in this phase of his life would reflect the quality of the environment.

European eel © Lane / NHPA

Content of the study

This study investigated the amount of endocrine disruption in European eels of Flemish surface waters. For this the blood of the eels was analysed for the presence of vitellogenins. Vitellogenins are proteins which are normally only produced by mature female fish. When juvenile or male fish are exposed to endocrine disrupting compounds they can also produce these proteins.

Main results of the study

Although the eels were exposed to different possible endocrine disrupting compounds (e.g. PCBs, organochlorine pesticides, heavy metals) at different concentrations, no effect of any these pollutants on the vitellogenin production was detected. The European eel is therefore at a juvenile phase (the yellow eel phase), not suited to detect endocrine disrupting compounds through vitallogenin production. This, although there are high concentrations of possible endocrine disrupting compounds present in Flanders.

You can find more information on this study through this link