Oxidative stress and biomarker responses in the Atlantic halibut after long term exposure to elevated CO2 and a range of temperatures

B Carney Almroth; K Bresolin de Souza; E Jönsson; J Sturve

doi:10.1016/j.cbpb.2019.110321

Oxidative stress and biomarker responses in the Atlantic halibut after long term exposure to elevated CO₂ and a range of temperatures

Comp Biochem Physiol B Biochem Mol Biol. 2019 Dec:238:110321. doi: 10.1016/j.cbpb.2019.110321. Epub 2019 Aug 28.

Authors

B Carney Almroth¹, K Bresolin de Souza¹, E Jönsson¹, J Sturve²

Affiliations

¹ Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, SE-405 30 Gothenburg, Sweden.
² Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, SE-405 30 Gothenburg, Sweden. Electronic address: joachim.sturve@bioenv.gu.se.

PMID: 31472240
DOI: 10.1016/j.cbpb.2019.110321

Abstract

CO₂ emissions from human activities are increasing, resulting in greater rates of change in the oceans, exceeding any other event in geological and historical records over the past 300 million years. Oceans are warming and pH levels are decreasing. Marine organisms will need to respond to multiple stressors and the potential consequences of global change-related effects in fish needs to be investigated. Fish are affected by many biotic and abiotic environmental variables, including temperature and CO₂ fluctuations, and it is therefore critical to investigate how these variables may affect physiological and biochemical processes. We investigated the effects of elevated CO₂ levels (pH of 8.0, which served as a control, or 7.6, which is predicted for the year 2100) combined with exposure to different temperatures (5, 10, 12, 14, 16, and 18 °C) in the Atlantic halibut (Hippoglossus hippoglossus) during a three month experiment. Since regulation of reactive oxygen species (ROS) is crucial for physiological processes the focus was on the antioxidant defense system and we assessed the effects on catalytic activities of antioxidant enzymes (SOD, CAT, GR, GST, GPx). In addition we also analyzed effects on cholinesterase enzymes (AChE and BChE), and CYP1A enzyme activities (EROD). The treatments resulted in oxidative stress, and damage was evident in the form of protein carbonyls which were consistently higher in the elevated CO₂-treated fish at all temperatures. Analyses of antioxidant enzymes did not show the same results, suggesting that the exposure to elevated CO₂ increased ROS formation but not defences. The antioxidant defense system was insufficient, and the resulting oxidative damage could impact physiological function of the halibut on a cellular level.

Keywords: Atlantic halibut; Carbon dioxide; Climate change; Hippoglossus hippoglossus; Ocean acidification; Oxidative stress; Teleost fish; Temperature.

MeSH terms

Animals
Carbon Dioxide / metabolism*
Flounder / metabolism*
Oxidation-Reduction
Oxidative Stress*
Temperature*
Time Factors

Substances

Carbon Dioxide