The disappearance of the European eel from the western Wadden Sea

A cohort model for the European eel is presented, which enables the interpretation of observed catches of yellow eel and silver eel in the western Wadden Sea in terms of recruitment data of glasseel. The model builds on various assumptions on length-dependent mortality and silvering rates and on the standard Dynamic Energy Budget (DEB) model which predicts length growth. DEB parameter values are estimated on the basis of literature data. The model predictions are generally in good agreement with the data, though the final decline in numbers in the 1980s occurs earlier than predicted. This suggests that the decrease in eel stock is not just a consequence of lower glasseel immigration but that local conditions must have impoverished, a phenomenon earlier observed in fresh water.