Long-term effects of ocean acidification upon energetics and oxygen transport in the European sea bass (Dicentrarchus labrax, Linnaeus)
WOS:000482385600002 The accumulation of CO2 in the atmosphere and resulting ocean acidification represent a threat to marine ecosystems. While acid-base regulatory capacity is well developed in marine fish, allowing compensation of extra-cellular pH during short-term hypercapnia, the possible energe...
Published in: | Marine Biology |
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Main Authors: | , , , , , , , |
Other Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2019
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-02868565 https://doi.org/10.1007/s00227-019-3562-9 |
Summary: | WOS:000482385600002 The accumulation of CO2 in the atmosphere and resulting ocean acidification represent a threat to marine ecosystems. While acid-base regulatory capacity is well developed in marine fish, allowing compensation of extra-cellular pH during short-term hypercapnia, the possible energetic costs of such regulation during long-term exposure remain to be established. In this study, juvenile European sea bass (Dicentrarchus labrax) were exposed from 2 days post-hatching to three different ocean acidification scenarios: control (present condition, PCO2-69pt 520 mu atm, pH 7.9), moderate acidification (PCO2\document\ treatments did not affect fish standard metabolic rate (SMR). However, the most severe acidification condition was associated with a significantly elevated maximum metabolic rate (MMR).This was supported by heavier gill system and higher blood haemoglobin concentration. A reduction of maximum cardiac frequency (f(Hmax)) during incremental warming of anaesthetized fish was also observed in both acidification scenarios. On the other hand, the critical oxygen level (O-2crit), the minimum oxygen level required to sustain SMR, did not differ among groups. The increased MMR, associated with maintained SMR, suggests that acid-base compensatory processes, although not increasing maintenance costs, may affect components of bass homeostasis, resulting in new internal physico-chemical conditions. The possibility that these alterations influence metabolic pathways and physiological functions involved in fish aptitude to maximally transport oxygen is discussed. |
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