Exploring the levels of rare earth elements and trace metals in macroalgae from different Antarctic islands

The Antarctic continent remains one of the most unexplored ecosystems in the world due to its extreme climatic conditions and to the fact that it is the most remote environment. Despite this, it is known that human activities are increasing the contamination of its ecosystems with pollutants, including metals. Algae are considered as important bioindicators for monitoring these kinds of pollutants, since they easily absorb organic and inorganic compounds. In this context, herein we report the presence of rare earth elements (REEs) and trace elements in three Antarctic macroalgae species, i.e., Desmarestia anceps, Palmaria decipiens, and Phaeurus antarcticus collected in different regions. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was employed to determine the concentration of 33 metals in the algal samples. Our findings revealed that the trace metals and REEs concentrations are dependent on the species and collection site. P. decipiens presented the greatest capacity to accumulate REEs; and D. anceps and P. decipiens presented the highest levels of trace metals, with Fe concentrations ranging from 166 to 6640 μg/g of dry algae biomass. The comparison of collection sites revealed that Deception Island had higher average total levels of REEs and trace metals than the other islands. These results provide an important contribution to the biomonitoring of trace metals and, especially, REEs, which remain poorly studied in the region.