Fig. 2. Total Hg concentration in the soft tissues (gill, digestive gland, mantle and foot) and byssus threads of the vent mussel B. azoricus kept in seawater for 3 weeks (Control), followed by daily exposure to 20 µg l^-1 inorganic Hg for 3 weeks (Exposure) followed by transfer to Hg-free seawater for an additional 3 weeks (Recovery). Vertical bars represent mean concentrations ± S.E.M. (N=15) in animals dissected at the end of each week of Control, Exposure and Recovery. Statistical differences between tissue levels at different experimental times was tested by one-way analysis of variance. Columns with the same letters are not significantly different according to a S-N-K multiple range test (P<0.05).