Spatial and temporal patterns of rare earth elements in the seaweed Saccarina latissima along the Norwegian coast

Rising rare earth elements (comprising the 15 lanthanoids plus yttrium (REY)) processing and use can lead to increased anthropogenic REY release into the environment, representing a potential environmental concern. Seaweeds due to their key ecological role as primary producers, habitat forming organisms and their tendency to accumulate metals have been largely used for monitoring anthropogenic pollution in coastal areas. In this study we assessed REY contents in Saccarina latissima seaweed to identify potential anthropogenic REY sources, and to relate accumulation patterns to different local abiotic and biotic conditions, including light regime, salinity, temperature and nutrient concentrations which can change over space and time. S. latissima specimens were collected at 2 depths (1-2 m and 8-9 m) in 4 locations at 4 time points (from May to August) along the Norwegian coastline over a germinating season. REY concentrations were analysed in freeze dried samples, each constituted by a pool of 10 specimens, with ICP-MS and relations between seaweed and REY accumulation, growth and protein contents were evaluated. Results provided in this study are expected to deepen the knowledge of the environmental bioavailability and accumulation patterns of REY along a spatial and temporal environmental gradient.