N. Nurra

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.

Trace elements, rare earth elements and inorganic arsenic in seaweeds from Giglio Island (Thyrrenian Sea) after the Costa Concordia shipwreck and removal

The occurrence of trace elements, REE and iAs was investigated in macroalgae collected from Giglio Island (Grosseto, Italy), 3 years after the Costa Concordia shipwreck recovery operations. There was a high variability of metals and REE between species, even those belonging to the same phylum. Arsenic level was found within the range of the Tuscany marine environment; the inorganic fraction was from 9% to 31%. Al, Be, Pb and Zn levels in seaweeds from Giglio Island were found to be significantly higher than in macroalgae from other islands of the Tuscany archipelago. REE were double the values found in the Tuscan islands of Elba and Capraia. We suggest that concentrations of metals and REE were influenced by the 3-year-long naval operations carried out for the Costa Concordia shipwreck rescue, and that macroalgae could be suitable bioindicators of perturbations in metal concentrations in the marine environment. CAPSULE Inorganic contaminants in seaweeds for Giglio Island.

Trace metal occurrence in Mediterranean seaweeds

Seaweeds have been used as animal feed since a long time and are consumed as food in several cultures. In fact, macroalgae are a source of protein, fiber, polyunsaturated fat, and minerals. The concentration of trace elements was determined in dominant macroalga species from three sites of the northwestern Mediterranean Sea. A high interspecies variability was observed, with higher metal levels in brown and green than those in red seaweeds. The maximum values set by European regulations for arsenic, mercury, and cadmium in food and feed were never exceeded, but a few samples were very close to limits set for mercury. Conversely, the maximum limit for lead in feed was exceeded in all species from one of the considered sites. Analogously, lead in seaweeds could constitute a potential risk for human health, due to the exceeding of the maximum value set for food supplements.