The interactions between trace elements and biogenic carbonates (marine mussel shells) in aqueous media were evaluated. The behaviour of Mn, Cu, Co, and Cd was investigated using spectrometric techniques (electrothermal atomic absorption, inductively coupled plasma atomic emission and electron paramagnetic resonance). The results obtained show that the metals considered do not form a distinct precipitated phase on the shell surfaces, but that they interact with the CaCO3. This study aimed to provide more information on the mechanisms involved in the storage of trace elements by the shells of marine bivalves. This would allow the use of mussel shells as an alternative to soft tissues for trace metal analyses in biological monitoring programmes.