Multilevel responses of adult zebrafish to crude and chemically dispersed oil exposure

  • Background: The application of chemical dispersants is a common remediation strategy when accidental oil spills occur in aquatic environments. Breaking down the oil slick into small droplets, dispersants facilitate the increase of particulate and dissolved oil compounds, enhancing the bioavailability of toxic oil constituents. The aim of the present work was to explore the effects of water accommodated fractions (WAF) of a naphthenic North Sea crude oil produced with and without the addition of the chemical dispersant FINASOL OSR 52 to adult zebrafish exposed for 3 and 21 d. Fish were exposed to environmentally relevant concentrations of 5% and 25% WAFOIL (1:200) and to 5% WAFOIL+D (dispersant–oil ratio 1:10) in a semi-static exposure setup. Results: The chemically dispersed WAF presented a 20-fold increase of target polycyclic aromatic hydrocarbons (PAHs) in the water phase compared to the corresponding treatment without dispersant and was the only treatment resulting in markedly bioaccumulation of PAHs in carcass after 21 d compared to the control. Furthermore, only 5% WAFOIL+D caused fish mortality. In general, the undispersed oil treatments did not lead to significant effects compared to control, while the dispersed oil induced significant alterations at gene transcription and enzyme activity levels. Significant up-regulation of biotransformation and oxidative stress response genes (cyp1a, gstp1, sod1 and gpx1a) was recorded in the livers. For the same group, a significant increment in EROD activity was detected in liver along with significant increased GST and CAT activities in gills. The addition of the chemical dispersant also reduced brain AChE activity and showed a potential genotoxic effect as indicated by the increased frequency of micronuclei in erythrocytes after 21 d of exposure. Conclusions: The results demonstrate that the addition of chemical dispersants accentuates the effect of toxic compounds present in oil as it increases PAH bioavailability resulting in diverse alterations on different levels of biological organization in zebrafish. Furthermore, the study emphasizes the importance to combine multilevel endpoints for a reliable risk assessment due to high variable biomarker responses. The present results of dispersant impact on oil toxicity can support decision making for oil spill response strategies.

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Author:Ada Esteban-Sánchez, Sarah JohannORCiDGND, Dennis Bilbao, Ailette Prieto, Henner HollertORCiDGND, Thomas-Benjamin SeilerORCiDGND, Amaia Orbea
Parent Title (English):Environmental sciences Europe
Place of publication:Berlin; Heidelberg
Document Type:Article
Date of Publication (online):2021/09/06
Date of first Publication:2021/09/06
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2021/11/15
Tag:Bioaccumulation; Biomarkers; Biotransformation; Chemical dispersants; Crude oil; Genotoxicity; Oil spills; Oxidative stress; Water accommodated fractions; Zebrafish
Issue:art. 106
Page Number:19
First Page:1
Last Page:19
Open Access funding enabled and organized by Projekt DEAL. The present study was funded by EU H2020-BG-2005-2 project GRACE (grant agreement #679266), Spanish MINECO (NACE project CTM2016-81130-R) and MECD (FPU16/01837 grant to A.E.), Basque Government (consolidated research groups IT810-13, IT1302-19, IT1213-19).
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung 4.0