Integrated use of bioaccumulation, genotoxic, and haematological endpoints to assess the effect of water remediation strategies on fish health: a complementary study

Biosorption successfully remediates saline water contaminated with legacy contaminants, but its effects on the health of marine organisms remain unclear. Therefore, our aim was to address this knowledge gap with data on the accumulation ability, as well as the cytogenetic and biochemical effects in turbot (Scophthalmus maximus). To this end, we exposed turbot for seven days to a mixture of remediated metals (Rem treatments: Cd, Hg, and Pb), with and without the presence of nanoparticles (NP), and compared them with the maximum allowable concentrations (MAC treatment) for effluent discharges. We determined the metal accumulation in the blood and kidney and evaluated haematological changes (red blood cell count, haemoglobin, and mean cell haemoglobin (MCH)) and genotoxicity (erythrocytic nuclear abnormalities assay) in the blood. The results showed that remediation with non-living macroalgae significantly reduced the metallic blood and kidney burdens in the Rem treatments. Furthermore, no genotoxic potential occurred in the Rem and MAC treatments in parallel with the reduction in MCH levels in the Rem treatments, which would reflect hematopoietic disturbances in the MAC. Our results validate biosorption remediation as we achieved a considerable reduction in metal loads while maintaining the health status of fish, highlighting the importance of testing water remediation methods in the biota.