Elevated CO2 enhances aerobic scope of a coral reef fish.
The uptake of anthropogenic CO2 by the ocean has been suggested to impact marine ecosystems by decreasing the respiratory capacity of fish and other water breathers. We investigated the aerobic metabolic scope of the spiny damselfish, Acanthochromis polyacanthus, from the Great Barrier Reef, Australia when exposed for 17 days to CO2 conditions predicted for the end of the century (946 μatm CO2). Surprisingly, resting O2 consumption rates were significantly lower and maximal O2 consumption rates significantly higher in high-CO2-exposed fish compared with control fish (451 μatm CO2). Consequently, high-CO2-exposed fish exhibited an unexpected increase in absolute (38%) and factorial aerobic scopes (47%). Haematological and muscle water changes associated with exercise were not affected by CO2 treatment. Thus, contrary to predictions, our results suggest that elevated CO2 may enhance aerobic scope of some fish species. Long-term experiments are now required to assess the response to elevated CO2 further, because developmental and transgenerational effects can be dramatic in fish. Ultimately, understanding the variability among species regarding the effects of CO2 on aerobic scope will be critical in predicting the impacts of ocean acidification on marine communities and ecosystems.
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.
Jodie L
JL
Rummer
Programme for Physiology and Neurobiology, Department of Biosciences, University of Oslo, 0316 Oslo, Norway; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, USA.
Jonathan A W
JA
Stecyk
Programme for Physiology and Neurobiology, Department of Biosciences, University of Oslo, 0316 Oslo, Norway.
Christine S
CS
Couturier
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia.
Sue-Ann
SA
Watson
Programme for Physiology and Neurobiology, Department of Biosciences, University of Oslo, 0316 Oslo, Norway.
Göran E
GE
Nilsson
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia.
Philip L
PL
Munday
aerobic scope; climate change; coral reef fish; ocean acidification