Metal mobility and bioaccumulation differences at lower trophic levels in marine ecosystems dominated by Sargassum species

Abstract

Concentrations of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn) and iron (Fe) were measured in three macroalgal species, Codium simulans, Sargassum sinicola and Gracilaria pachydermatica, and in the sea slug Elysia diomedea, living in marine ecosystems dominated by Sargassum species and located near exploited phosphorite deposits. Metal concentrations in macroalgae and sea slugs were significantly different among sites. The highest concentrations of Cd recorded in C. simulans and S. sinicola, as well as in E. diomedea were recorded at the site closest to the phosphorite deposit. In general, Cd and Zn concentrations in E. diomedea were higher than those recorded in specimens of C. simulans, S. sinicola and G. pachydermatica. In contrast, Pb, Cu, and Fe concentrations in E. diomedea were lower than or similar to those in macroalgae from all sampled sites. The information generated contributes to the knowledge about potential mobility and metal bioaccumulation at lower trophic levels in marine eco systems.