Seawater carbonate chemistry and behavioural abnormalities in coral reef fish

• Main Authors: Jarrold, Michael, Humphrey, Craig, McCormick, Mark I, Munday, Philip L
• Format: Dataset
• Language: English
• Published: PANGAEA 2017
• Subjects: Acanthochromis polyacanthus; Alkalinity; total; standard deviation; Amphiprion percula; Animalia; Aragonite saturation state; Behaviour; Bicarbonate ion; Bramble_reef; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chordata; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Identification; Individuals; Laboratory experiment; Lateralization; Nekton; Number of observations; OA-ICC; Ocean Acidification International Coordination Centre; Other; Partial pressure of carbon dioxide; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Registration number of species; Salinity; Single species; South Pacific; Species; Temperature; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.893703; https://doi.org/10.1594/PANGAEA.893703

Elevated CO2 levels associated with ocean acidification (OA) have been shown to alter behavioural responses in coral reef fishes. However, all studies to date have used stable pCO2 treatments, not considering the substantial diel pCO2 variation that occurs in shallow reef habitats. Here, we reared juvenile damselfish, Acanthochromis polyacanthus, and clownfish, Amphiprion percula, at stable and diel cycling pCO2 treatments in two experiments. As expected, absolute lateralization of A. polyacanthus and response to predator cue of Am. percula were negatively affected in fish reared at stable, elevated pCO2 in both experiments. However, diel pCO2 fluctuations reduced the negative effects of OA on behaviour. Importantly, in experiment two, behavioural abnormalities that were present in fish reared at stable 750 µatm CO2 were largely absent in fish reared at 750 ± 300 µatm CO2. Overall, we show that diel pCO2 cycles can substantially reduce the severity of behavioural abnormalities caused by elevated CO2. Thus, past studies may have over-estimated the impacts of OA on the behavioural performance of coral reef fishes. Furthermore, our results suggest that diel pCO2 cycles will delay the onset of behavioural abnormalities in natural populations.