Trace element patterns in marine macroalgae

Novel information on interspecific variation in trace element accumulation in seaweeds is provided. Concentrations and concentration factors (CFs) of a wide set of elements (As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Se, Sr, U, V and Zn) in 26 dominant macroalgae from the Gulf of Thessaloniki, Aegean Sea were determined and compared. Uni-and multivariate data analyses were applied. Phaeophyceae showed higher concentrations and CFs of As and Sr than Rhodophyta and Chlorophyta, indicating that the accumulation of these elements is closely related to species biochemical composition. Filamentous macroalgae displayed higher concentrations and CFs of several elements, particularly Cd, Co, Cr, Cu, Mn and V than sheet-like, coarsely-branched and/or thick-leathery macroalgae, irrespective of phylogenetic relationships, indicating that the accumulation of several elements is largely related to thallus morphology and growth strategy. On a species basis, Cystoseira spp. showed both the highest concentrations and CFs of As, Padina pavonica of Sr and U, Ceramium spp. of Mn, Ceramium and Cladophora species of Co and Cu, Cladophora prolifera of Cr and Polysiphonia deusta and Ulva clathrata of Cd. Se concentration in Ulva rigida correlated positively with seawater Se concentration, and As concentration in this species with sediment As concentration. Thereby, these seaweeds could be regarded as potential biomonitors for the respective elements. A literature review was performed and global element concentrations and CFs were presented for seaweeds from genera collected during this survey. The data presented can contribute to the interpretation of biomonitoring data and the design of biomonitoring programs for the protection and management of coastal environments.