A first report of rare earth elements in northwestern Mediterranean seaweeds

The concentrations of rare earth elements (REE) were determined by ICP-MS in dominant seaweed species, collected from three locations of the northwestern Mediterranean Sea. This is the first study to define levels and patterns of REE in macro algae from these coastal areas. Rare elements are becoming emerging inorganic contaminants in marine ecosystems, due to their worldwide increasing applications in industry, technology, medicine and agriculture. Significant inter-site and interspecies differences were registered, with higher levels of REE in brown and green macro algae than in red seaweeds. Levels of light REE were also observed to be greater compared to heavy REE in all samples. One of the investigated locations (Bergeggi, SV) had higher REE and ΣREE concentrations, probably due to its proximity to an important commercial and touristic harbor, while the other two sites were less affected by anthropogenic contaminations, and showed comparable REE patterns and lower concentrations. Capsule: Rare earth elements in seaweeds. - Highlights: • Rare earth elements (REE) were detected in Mediterranean macro algae. • Significant inter-site and interspecies differences were found. • Levels of Light REE were greater than Heavy REE in all samples. • REE could constitute a pollution tracer, being more concentrated in polluted areas.