Assessment of emerging contaminant occurrence in key species of anthozoan in the Mediterranean benthic communities

The biodiversity of the Mediterranean Sea is under severe threat from climate change and anthropic pressure, in particular pollution. Plastic and emerging contaminants (ECs) ever-growing abundance and widespread distribution are raising concerns as one of the most important threats to the marine environment. Indeed, several studies have been conducted in recent years, however, there remains a significant scarcity of studies, especially concerning anthozoan in the Mediterranean region. This study aimed to investigate for the first time the occurrence of emerging contaminants (ECs) in five key anthozoan species in the Mediterranean (Cladocora caespitosa, Eunicella cavolini, Madracis pharensis, Parazoanthus axinellae, and Paramuricea clavata). Specifically, we focused on phthalic acid esters (PAEs), active pharmaceutical ingredients (APIs), and UV-filters molecules, analyzing coral tissues by solid phase microextraction (SPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to detect contamination. Our investigation revealed variable capacities for bioaccumulation among the species, indicating complexity in the absorption dynamics of these contaminants. We discussed inter and intra-specific variability and their potential explanations in relation to growth form and life stage of the colonies, as well as the environmental conditions such as currents and habitat where they are usually found. It is important to notice that even low concentrations of these contaminants may have significant adverse effects due to continuous exposition. Therefore, we examined the potential sublethal impacts, including reduced energy production and photosynthetic activity, growth inhibition, compromised detoxification, and excessive immune system responses. Further research is needed to fully understand the dynamics of accumulation and the biological consequences of these contaminants, especially considering the additional threats posed by climate change. This is important to develop more effective management strategies to mitigate their impact on the marine ecosystem, given the crucial role these species play in shaping habitats along the Mediterranean coast.