Comparative developmental toxicity of conventional oils and diluted bitumen on early life stages of the rainbow trout (Oncorhynchus mykiss).

Schiano Di Lombo, Magali; Weeks-Santos, Shannon; Clérandeau, Christelle; Triffault-Bouchet, Gaëlle; Langlois, Valérie S. ORCID: https://orcid.org/0000-0003-4031-6838; Couture, Patrice ORCID: https://orcid.org/0000-0002-1944-5136 et Cachot, Jérôme (2021). Comparative developmental toxicity of conventional oils and diluted bitumen on early life stages of the rainbow trout (Oncorhynchus mykiss). Aquatic Toxicology , vol. 239 . p. 105937. DOI: 10.1016/j.aquatox.2021.105937.

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Résumé

Petroleum hydrocarbons are widely used and transported, increasing the risks of spills to the environment. Although conventional oils are the most commonly produced, the production of unconventional oils (i.e. diluted bitumen or dilbit) is increasing. In this study, we compared the effects of conventional oils (Arabian Light and Lloydminster) and dilbits (Bluesky and Clearwater) on early life stages of a salmonid. To this end, aqueous fractions (WAF: water accommodated fraction) of these oils were extracted using mountain spring water. Rainbow trout (Oncorhynchus mykiss) larvae were exposed to 10 and 50% dilutions of these WAFs from hatching (340 DD; degree days) until yolk sac resorption (541 DD). Exposure to WAFs increased skeletal malformations (both dilbits) and hemorrhage (both conventional oils and Bluesky) and decreased head growth (Arabian Light). In addition, increases in EROD activity and DNA damage were measured for all oils and an increase in cyp1a gene expression was measured for Arabian Light, Bluesky and Clearwater. The PAH and C₁₀ C₅₀ concentrations were positively correlated to total larval EROD activity, whereas concentrations of total hydrocarbons, VOCs, PAHs, and C₁₀ C₅₀ were positively correlated to cyp1a expression. Total hydrocarbon, VOC, and C₁₀ C₅₀ concentrations were also negatively correlated to larval growth. This study supports that petroleum hydrocarbons are toxic to early developmental stages of rainbow trout and show that their degree and spectrum of toxicity depends on their chemical composition.

Type de document:	Article
Mots-clés libres:	conventional oils; diluted bitumen; aqueous fraction; embryo-larval toxicity; swimming behavior; molecular responses
Centre:	Centre Eau Terre Environnement
Date de dépôt:	15 sept. 2021 17:36
Dernière modification:	11 août 2023 04:00
URI:	https://espace.inrs.ca/id/eprint/11940

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