Effects of seawater acidification and cadmium on the antioxidant defense of flounder Paralichthys olivaceus larvae

Increasing atmospheric carbon dioxide has led to a decrease in the pH of the ocean, which influences the special ion of heavy metals and consequently affects metal toxicity in marine organisms. To investigate the effects of seawater acidification and metals on the antioxidant defenses of marine fish...

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Bibliographic Details
Published in:Science of The Total Environment
Main Authors: Cui, Wenting, Cao, Liang, Liu, Jinhu, Ren, Zhonghua, Zhao, Bo, Dou, Shuozeng
Format: Report
Language:English
Published: ELSEVIER 2020
Subjects:
Early life stages
Cadmium
Seawater acidification
Metal accumulation
Oxidative stress
Marine fish
Environmental Sciences & Ecology
Environmental Sciences
EARLY-LIFE STAGES
OCEAN ACIDIFICATION
OREOCHROMIS-NILOTICUS
CARASSIUS-AURATUS
OLIVE FLOUNDER
FISH
RESPONSES
TOXICITY
Ocean acidification
Online Access:http://ir.qdio.ac.cn/handle/337002/167225
https://doi.org/10.1016/j.scitotenv.2020.137234
Description
Summary:Increasing atmospheric carbon dioxide has led to a decrease in the pH of the ocean, which influences the special ion of heavy metals and consequently affects metal toxicity in marine organisms. To investigate the effects of seawater acidification and metals on the antioxidant defenses of marine fishes, the flounder Para, ichthys olivaceus, was continuously exposed to cadmium (Cd; control, 0.01 and 0.15 mg L-1) and acidified seawater (control (pH 8.10), 7.70 and 7.30) for 49 days from embryogenesis to settlement. The results demonstrated that both Cd and acidified seawater could induce oxidative stress and consequently cause lipid peroxidation (LPO) in the larvae. Antioxidants (i.e., superoxide dismutase, SOD; catalase, CAT; reduced glutathione, GSH; glutathione 5-transferase, GST; glutathione peroxidase, GPx; and glutathione reductase, GR) functioned to defend the larvae against oxidative damage. Overall, Cd induced (SOD, GST and GSH) or inhibited (CAT and GPx) the enzymatic activities or contents of all the selected antioxidants except for GR. The antioxidants responded differently to seawater acidification, depending on their interaction with the metal. Similarly, the mRNA expressions of the antioxidant-related genes were upregulated (sod, gr and gst) or downregulated (cat and gpx) in response to increasing Cd exposure. Seawater acidification did not necessarily affect all of the biomarkers; in some cases (eg, SOD and sod, GR and gr), Cd stress may have exceeded and masked the stress from seawater acidification in regulating the antioxidant defense of the larvae. The integrated biomarker response (IBR) was enhanced with increasing levels of the stressors. These findings support the hypothesis that seawater acidification not only directly affects the antioxidant defense in flounder larvae but also interacts with Cd to further regulate this defense. This study has ecological significance for assessing the long-term impacts of ocean acidification and metal pollution on the recruitment of fish populations in the ...

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