Seawater carbonate chemistry and fish cognitive performance

• Main Authors: Paula, José Ricardo, Baptista, Miguel, Carvalho, Francisco, Repolho, Tiago, Bshary, Redouan, Rosa, Rui
• Format: Dataset
• Language: English
• Published: PANGAEA 2019
• Subjects: Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Behaviour; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Category; Chordata; Coast and continental shelf; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater; Identification; Indian Ocean; Laboratory experiment; Labroides dimidiatus; Nekton; Number; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide; Indian; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.914654; https://doi.org/10.1594/PANGAEA.914654

Ocean acidification is one of the many consequences of climate change. Various studies suggest that marine organisms' behaviour will be impaired under high CO2. Here, we show that the cognitive performance of the cleaner wrasse, Labroides dimidiatus, has not suffered from the increase of CO2 from pre-industrial levels to today, and that the standing variation in CO2 tolerance offers potential for adaptation to at least 750 µatm. We acclimated cleaners over 30 days to five levels of pCO2, from pre-industrial to high future CO2 scenarios, before testing them in an ecologically relevant task—the ability to learn to prioritize an ephemeral food source over a permanent one. Fish learning abilities remained stable from pre-industrial to present-day pCO2. While performance was reduced under mid (750 µatm) and high CO2 (980 µatm) scenarios, under the former 36% of cleaners still solved the task. The presence of tolerant individuals reveals potential for adaptation, as long as selection pressure on cognitive performance is strong. However, the apparent absence of high CO2 tolerant fish, and potentially synergistic effects between various climate change stressors, renders the probability of further adaptation unlikely.