Metal body burden and tissue oxidative status in the bivalve Venerupis decussata from Tunisian coastal lagoons

Coastal transitional waters are exposed to many anthropogenic threats. This study aims to assess the trace metals' pollution status of transitional waters by evaluating its biological effects in the clam Venerupis decussata. Among the studied sites along the Tunisian littoral, South Tunis and Boughrara were the most impacted, since clams from these two lagoons presented significant differences in: (i) trace metal contents, (ii) in-cell hydrogen peroxide, (iii) enzymatic and non-enzymatic defenses, (iv) damage to lipids and proteins, and (v) protein post-translational modifications. These changes related to evident histopathological traits. PCA showed a clear separation between the digestive gland and gills tissues and illustrated an impact gradient in Tunisian coastal lagoons. Water temperature was revealed as an added natural stressor that, when concurring with high pollution, may jeopardize an ecosystem's health and contribute to the accumulation of hazardous metals in organisms.

This study was supported by the Spanish Ministry of Economy and Competitiveness -CTM2016-75908-R-, by the Andalusian Plan of Research, Development, and Innovation, and by the University of Cordoba “Plan Propio” program to group BIO187 (Spain). Safa Bejaoui stay in Cordoba was funded by the Tunisian government, Ministry of Higher Education and Scientific Research, University of Tunis EL Manar, Laboratory of Ecology, Biology and Physiology of Aquatic Organisms -EBPAO, LR18ES41- (Tunisia). Pedro M. Costa acknowledges Fundação para a Ciência e Tecnologia -FCT-MCES- for the grant IF/00265/2015 and for the support to UCIBIO, Applied Molecular Biosciences Unit -UID/Multi/04378/2019- (Portugal).

Peer reviewed