Embryonic cardio-respiratory impairments in rainbow trout (Oncorhynchus mykiss) following exposure to hydraulic fracturing flowback and produced water. (1st October 2022)

• Record Type: Journal Article
• Authors: Folkerts, Erik J.; Snihur, Katherine N.; Zhang, Yifeng; Martin, Jonathan W.; Alessi, Daniel S.; Goss, Greg G.
• Is Part Of: Environmental pollution. Volume 310(2022)
• Publication Date: 2022-10-01
• Subjects: Hydraulic fracturing -- Cardiac -- Rainbow trout -- Respiration -- Embryonic; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.119886
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: During hydraulic fracturing, wastewaters - termed flowback and produced water (FPW) - are created as a by-product during hydrocarbon extraction. Given the large volumes of FPW that a single well can produce, and the history of FPW release to surface water bodies, it is imperative to understand the hazards that hydraulic fracturing and FPW pose to aquatic biota. Using rainbow trout embryos as model organisms, we investigated impacts to cardio-respiratory system development and function following acute (48 h) and sub-chronic (28-day) FPW exposure by examining occurrences of developmental deformities, rates of embryonic respiration (MO2 ), and changes in expression of critical cardiac-specific genes. FPW-exposed embryos had significantly increased rates of pericardial edema, yolk-sac edema, and tail/trunk curvatures at hatch. Furthermore, when exposed at three days post-fertilization (dpf), acute 5% FPW exposures significantly increased embryonic MO2 through development until 15 dpf, where a switch to significantly reduced MO2 rates was subsequently recorded. A similar trend was observed during sub-chronic 1% FPW exposures. Interestingly, at certain specific developmental timepoints, previous salinity exposure seemed to affect embryonic MO2 ; a result not previously observed. Following acute FPW exposures, embryonic genes for cardiac development and function were significantly altered, although at termination of sub-chronic exposures, significant changes to these same genes were not found. Together, our evidence of induced developmental deformities, modified embryonic MO2, and altered cardiac transcript expression suggest that cardio-respiratory tissues are toxicologically targeted following FPW exposure in developing rainbow trout. These results may be helpful to regulatory bodies when developing hazard identification and risk management protocols concerning hydraulic fracturing activities. Graphical abstract: Image 1 Highlights: Impacts of flowback and produced water (FPW) exposure on salmonid development and cardio-respiratory function. Increased mortality, pericardial and yolk-sac edema, and tail/spine curvatures in exposed embryos. Exposed embryos displayed altered respiration past initial acute exposures. Altered expression of key cardiac developmental, structural, and electrophysiological genes. Embryos earlier in development were more susceptible to FPW-induced sublethal toxicity.