Ocean acidification compromises energy management in Sparus aurata (Pisces: Teleostei)

• Published in: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology
• Main Authors: Ruiz-Jarabo, Ignacio, Gregório, Silvia Filipa, Alves, Alexandra, Mancera, Juan Miguel, Fuentes, Juan
• Other Authors: Ministério da Ciência, Tecnologia e Ensino Superior (Portugal), European Commission, Fundação para a Ciência e a Tecnologia (Portugal)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: Sparus aurata; Energy management; Fish; Intermediary metabolism; Ocean acidification
• Online Access: http://hdl.handle.net/10261/343348; https://doi.org/10.1016/j.cbpa.2021.110911; https://doi.org/10.13039/501100006111; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100001871; https://api.elsevier.com/content/abstract/scopus_id/85102392756

The effects of ocean acidification mediated by an increase in water pCO2 levels on marine organisms are currently under debate. Elevated CO2 concentrations in the seawater induce several physiological responses in teleost fish, including acid-base imbalances and osmoregulatory changes. However, the consequences of CO2 levels enhancement on energy metabolism are mostly unknown. Here we show that 5 weeks of exposure to hypercapnia (950 and 1800 μatm CO2) altered intermediary metabolism of gilthead seabream (Sparus aurata) compared to fish acclimated to current ocean values (440 μatm CO2). We found that seabream compromises its physiological acid-base balance with increasing water CO2 levels and the subsequent acidification. Intestinal regions (anterior, mid, and rectum) engaged in maintaining this balance are thus altered, as seen for Na+/K+-ATPase and the vacuolar-type H+-ATPase activities. Moreover, liver and muscle counteracted these effects by increasing catabolic routes e.g., glycogenolysis, glycolysis, amino acid turnover, and lipid catabolism, and plasma energy metabolites were altered. Our results demonstrate how a relatively short period of 5 weeks of water hypercapnia is likely to disrupt the acid-base balance, osmoregulatory capacity and intermediary metabolism in S. aurata. However, long-term studies are necessary to fully understand the consequences of ocean acidification on growth and other energy-demanding activities, such as reproduction. This study was partly supported by the Ministry of Science and Higher Education and European Social Funds through the Portuguese National Science Foundation (FCT) by Project PTDC/MAR-BIO/3034/2014 to JF. CCMar is supported by national funds from the Portuguese Foundation for Science and Technology (FCT) through project UIDB/04326/2020. Peer reviewed