Mercury (Hg) bioaccumulation and depuration potential was assessed in the glass eel Anguilla anguilla over a 30-day period, through a mesocosm experiment. During exposure period, glass eels exhibited a significant increase in Hg concentration compared with the control ones, revealing great accumulation capability. Distinct bioaccumulation kinetics were observed depending on the exposure concentrations: a saturation model and a linear accumulation model were achieved for low and high Hg levels, respectively. After 72 h of depuration, glass eels lost around 2 and 10 % of the Hg previously accumulated; however, until the end of the experiment, they never reached the original baseline condition. Most importantly, organisms exposed to high Hg concentrations still retained contaminant levels exceeding the European threshold regulating human food consumption. This may raise serious health concerns, due to the species’ rising interest in the international cuisine.