First toxicological study in two commercial shark species from a Mediterranean Marine Protected Area

Large urban and industrial settlements, and the intense maritime traffic make the Mediterranean one of the most polluted areas in the world. This basin hosts considerable marine biodiversity, including many elasmobranchs, which are extremely vulnerable to environmental contamination due their life history traits. The impact of this threat on the cartilaginous fishes is still poorly studied, as well as the possible consequences for human health, in case of consumption of sharks, are uncertain. To fill this knowledge gap, quantitative and qualitative assessments of three groups of persistent organic pollutants (POPs) were carried out in the muscle and liver of two shark species, Mustelus punctulatus and Mustelus mustelus, caught in the Marine Protected Area (MPA) of Egadi Islands (South-Central Mediterranean Sea) between 2021 and 2023. As sharks are one of the top predators inhabiting the MPA, they can be considered a bioindicator of the local environmental status. Paradoxically, although M. punctulatus and M. mustelus have considerable commercial value for human consumption in the MPA, they are listed as Vulnerable by the IUCN in the Mediterranean. Regarding POPs levels, the results showed a trend of PCBs > DDTs >> HCB in liver and muscle for both species. Our results can significantly contribute to clarify the toxicological status of these species, allowing a first evaluation of the real risks both for the local marine life and for human health.