Unlocking the relationship between tourism and bivalve health: A comprehensive study of Donax trunculus as environmental and public health indicators in Morocco.

This study assessed the levels of Cd, Cu and Pb in the sentinel bivalve Donax trunculus collected from two touristic Moroccan sandy beaches, namely Agadir and Taghazout, in Morocco. The results revealed higher metal contamination in D. trunculus specimens collected from Taghazout compared to those from Agadir. Among the metals analyzed, Pb was found to pose the greatest risk to human health, followed by Cd and Cu. The study also investigated the presence of the trematode parasite Bacciger bacciger in D. trunculus specimens. The parasite was found only in female D. trunculus from Taghazout, with infection rates ranging from 11% to 46%. Furthermore, significantly higher levels of oxidative stress biomarkers were observed in specimens from Taghazout, where positive correlations were observed between Cu, Cd, Glutathione S-Transferase, and parasite prevalence, as well as between Pb and Catalase. In the case of D. trunculus collected from Agadir, Malondialdehyde levels were positively correlated with Cd and negatively correlated with Pb, while Catalase levels were negatively correlated with Cu. Complex interactions emerged between metal pollution, parasitic infection, and oxidative stress biomarkers in D. trunculus from two Moroccan coastal sites. Evaluating biotic stress synergies with biomarkers shows promise for integrating biological implications of coastal contamination.