The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification
Ocean acidification is a phenomenon associated with global change and anthropogenic CO2 emissions that is changing the chemistry of seawater. These changes result in elevated pCO2 and reduced pH in seawater and this is impacting marine organisms in various ways. Marine fishes are considered generall...
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ftrhodesunivcory:vital:26094 2023-05-15T17:49:03+02:00 The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification Edworthy, Carla 2018 74 pages pdf http://hdl.handle.net/10962/51417 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:26094 English eng Rhodes University Faculty of Science, Ichthyology and Fisheries Science http://hdl.handle.net/10962/51417 vital:26094 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:26094 Edworthy, Carla Argyrosomus Argyrosomus -- Growth Argyrosomus -- Mortality Argyrosomus -- Larvae -- Ecology Ocean acidification Marine ecology -- South Africa Carbon dioxide -- Physiological effect text Thesis Masters MSc 2018 ftrhodesunivcory 2022-12-26T09:11:24Z Ocean acidification is a phenomenon associated with global change and anthropogenic CO2 emissions that is changing the chemistry of seawater. These changes result in elevated pCO2 and reduced pH in seawater and this is impacting marine organisms in various ways. Marine fishes are considered generally tolerant to conditions of ocean acidification; however, these assumptions are based on juvenile and adult fish tolerance and the larval stages have not been frequently assessed. Furthermore, it has been suggested that temperate species, particularly those with an estuarine association, may be tolerant to variable CO2 and pH. This study used an eco-physiological approach to understand how the early life stages of Argyrosomus japonicus, an estuarine dependent marine fisheries species found in warm-temperate regions, may be impacted by ocean acidification. The metabolic response of early stage larvae (hatching to early juvenile stage) was assessed under conditions of elevated pCO2 and reduced pH in a controlled laboratory setting. Small volume static respirometry was used to determine the oxygen consumption rate of larvae raised in three pCO2 treatments including a low (pCO2 = 327.50 ± 80.07 µatm at pH 8.15), moderate (pCO2 477.40 ± 59.46 µatm at pH 8.03) and high treatment (PCO2 910.20 ± 136.45 µatm at pH 7.78). These treatment levels were relevant to the present (low) and projected conditions of ocean acidification for the years 2050 (moderate) and 2100 (high). Prior to experimentation with ocean acidification treatments, baseline metabolic rates and diurnal variation in oxygen consumption rates in early stage A. japonicus was determined. Distinct ontogenetic structuring of metabolic rates was observed in early stage A. japonicus, with no cyclical fluctuations in metabolic rate occurring during the 24 hour photoperiodic cycle. Pre-flexion larvae showed no metabolic response to ocean acidification treatments; however post-flexion stage larvae showed metabolic depression of standard metabolic rate in the moderate ... Master Thesis Ocean acidification Rhodes University Cory: Repository |
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Open Polar |
collection |
Rhodes University Cory: Repository |
op_collection_id |
ftrhodesunivcory |
language |
English |
topic |
Argyrosomus Argyrosomus -- Growth Argyrosomus -- Mortality Argyrosomus -- Larvae -- Ecology Ocean acidification Marine ecology -- South Africa Carbon dioxide -- Physiological effect |
spellingShingle |
Argyrosomus Argyrosomus -- Growth Argyrosomus -- Mortality Argyrosomus -- Larvae -- Ecology Ocean acidification Marine ecology -- South Africa Carbon dioxide -- Physiological effect Edworthy, Carla The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification |
topic_facet |
Argyrosomus Argyrosomus -- Growth Argyrosomus -- Mortality Argyrosomus -- Larvae -- Ecology Ocean acidification Marine ecology -- South Africa Carbon dioxide -- Physiological effect |
description |
Ocean acidification is a phenomenon associated with global change and anthropogenic CO2 emissions that is changing the chemistry of seawater. These changes result in elevated pCO2 and reduced pH in seawater and this is impacting marine organisms in various ways. Marine fishes are considered generally tolerant to conditions of ocean acidification; however, these assumptions are based on juvenile and adult fish tolerance and the larval stages have not been frequently assessed. Furthermore, it has been suggested that temperate species, particularly those with an estuarine association, may be tolerant to variable CO2 and pH. This study used an eco-physiological approach to understand how the early life stages of Argyrosomus japonicus, an estuarine dependent marine fisheries species found in warm-temperate regions, may be impacted by ocean acidification. The metabolic response of early stage larvae (hatching to early juvenile stage) was assessed under conditions of elevated pCO2 and reduced pH in a controlled laboratory setting. Small volume static respirometry was used to determine the oxygen consumption rate of larvae raised in three pCO2 treatments including a low (pCO2 = 327.50 ± 80.07 µatm at pH 8.15), moderate (pCO2 477.40 ± 59.46 µatm at pH 8.03) and high treatment (PCO2 910.20 ± 136.45 µatm at pH 7.78). These treatment levels were relevant to the present (low) and projected conditions of ocean acidification for the years 2050 (moderate) and 2100 (high). Prior to experimentation with ocean acidification treatments, baseline metabolic rates and diurnal variation in oxygen consumption rates in early stage A. japonicus was determined. Distinct ontogenetic structuring of metabolic rates was observed in early stage A. japonicus, with no cyclical fluctuations in metabolic rate occurring during the 24 hour photoperiodic cycle. Pre-flexion larvae showed no metabolic response to ocean acidification treatments; however post-flexion stage larvae showed metabolic depression of standard metabolic rate in the moderate ... |
format |
Master Thesis |
author |
Edworthy, Carla |
author_facet |
Edworthy, Carla |
author_sort |
Edworthy, Carla |
title |
The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification |
title_short |
The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification |
title_full |
The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification |
title_fullStr |
The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification |
title_full_unstemmed |
The metabolic physiology of early stage Argyrosomus japonicus with insight into the potential effects of pCO2 induced ocean acidification |
title_sort |
metabolic physiology of early stage argyrosomus japonicus with insight into the potential effects of pco2 induced ocean acidification |
publisher |
Rhodes University |
publishDate |
2018 |
url |
http://hdl.handle.net/10962/51417 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:26094 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
http://hdl.handle.net/10962/51417 vital:26094 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:26094 |
op_rights |
Edworthy, Carla |
_version_ |
1766155258725138432 |