Interannual patterns of variation in concentrations of trace elements in arms of Octopus vulgaris

Mean concentrations of trace elements analysed were in the following order: As > Zn > Fe > Cu ≫ Cd > Pb > Se > Mn ≫ Hg. The results of speciation of arsenic demonstrate that virtually all arsenic was in the arsenobetaine form, which is the less toxic form. The concentrations of several trace elements were generally high in samples from Viana in 2002. Cadmium concentrations were above the legal limit for human consumption in samples from Viana in 2002 and two of these animals also had lead concentrations that exceeded legal limits. Mercury appeared in all samples but levels were within legally defined safe limits. No relationship was detected between trace element concentrations and size or maturity of octopus.