Biochemical responses of Solea senegalensis after continuous flow exposure to urban effluents

- S. senegalensis were exposed to a continuous flow at 5 different effluent concentrations.
- Sub-lethal effects were measured by a selected battery of biomarkers.
- Contaminants of emerging concern concentrations were reduced after photobiotreatment application.
- Biochemical responses were statistically related with the chemical composition of the effluent.
- Additional depuration treatment allowed the fish detoxification mechanism to function.

Urban effluent potential toxicity was assessed by a battery of biomarkers aimed at determining sub-lethal effects after continuous exposure on the marine organism Solea senegalensis. Specimens were exposed to five effluent concentrations (1/2, 1/4, 1/8, 1/16, 1/32) during 7-days, simulating the dispersion plume at the discharge point. Three different groups of biomarkers were selected in the present study: biomarkers of exposure (Phase I: EROD and DBF; Phase II: GST), biomarkers with antioxidant responses (GR and GPX) and biomarkers of effects (DNA damage and LPO). Additionally, a biological depuration treatment (photobiotreatment (PhtBio)) was tested in order to reduce the adverse effects on aquatic organisms. Effluent exposure caused sub-lethal responses in juvenile fish suggesting oxidative stress. After PhtBio application, concentrations of the major part of measured contaminants were reduced, as well as their bioavailability and adverse effects.

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