Elemental fingerprinting of sea urchin (Paracentrotus lividus) gonads to assess food safety and trace its geographic origin

Sea urchin gonads are an economically valuable seafood item, considered a delicacy in many parts of the world. However, its consumption can either pose a food safety threat, as they accumulate potentially toxic elements from contaminated environments or promote the depletion of natural stocks due to the high demand. Knowing their harvesting location is therefore paramount to guarantee food safety and the conservation of natural stocks. In this study, the elemental fingerprints of sea urchin (Paracentrotus lividus) gonads collected in several locations along the Portuguese coast, in 2020 and 2021, were used to assess the levels of some potentially toxic elements (i.e., As, Cu, Pb and Zn) and to trace the harvesting location of this marine resource. P. lividus gonads presented mean levels of As, Cu, Pb and Zn above the thresholds recommended for human consumption (considering mollusks due to the absence of safety thresholds for echinoderms), in at least one of the sampling locations. The elemental fingerprints of gonads hold the potential to trace the harvesting location of P. lividus, even when it was used elemental fingerprints of different years to train and test the models.