DOI: 10.5061/dryad.2m353
title: Data from: CO2-induced ocean acidification does not affect individual or group behaviour in a temperate damselfish

description: Open ocean surface CO2 levels are projected to reach approximately
 800 µatm, and ocean pH to decrease by approximately 0.3 units by the year
 2100 due to anthropogenic CO2 emissions and the subsequent process of
 ocean acidification (OA). When exposed to these CO2/pH values, several
 fish species display abnormal behaviour in laboratory tests, an effect
 proposed to be linked to altered neuronal GABAA­ receptor function.
 Juvenile blacksmith (Chromis punctipinnis) are social fish that regularly
 experience CO2/pH fluctuations through kelp forest diurnal primary
 production and upwelling events, so we hypothesized that they might be
 resilient to OA. Blacksmiths were exposed to control conditions
 (pH ∼ 7.92; pCO2 ∼ 540 µatm), constant acidification (pH ∼ 7.71;
 pCO2 ∼ 921 µatm) and oscillating acidification (pH ∼ 7.91, pCO2 ∼ 560 µatm
 (day), pH ∼ 7.70, pCO2 ∼ 955 µatm (night)), and caught and tested in two
 seasons of the year when the ocean temperature was different: winter
 (16.5 ± 0.1°C) and summer (23.1 ± 0.1°C). Neither constant nor oscillating
 CO2-induced acidification affected blacksmith individual light/dark
 preference, inter-individual distance in a shoal or the shoal's
 response to a novel object, suggesting that blacksmiths are tolerant to
 projected future OA conditions. However, blacksmiths tested during the
 winter demonstrated significantly higher dark preference in the individual
 light/dark preference test, thus confirming season and/or water
 temperature as relevant factors to consider in behavioural tests.
description: Kwan et
 al.,Dryad_data_FinalDue to anthropogenic
 CO<sub>2</sub> emissions and the subsequent process of ocean
 acidification (OA), open ocean surface CO<sub>2</sub> levels
 are projected to more than double to ~1,000 μatm, and pH to decrease by
 ~0.3 units by the year 2100. When exposed to these
 CO<sub>2</sub>/pH values, several fish species display
 abnormal behaviour in laboratory tests, an effect proposed to be linked to
 altered neuronal GABA<sub>A</sub> receptor function. This
 study examined the effects of constant and oscillating OA-like conditions
 on individual and group behaviour of juvenile blacksmith (<i>Chromis
 punctipinnis</i>), a social fish that regularly experiences
 CO<sub>2</sub>/pH fluctuations through kelp forest diurnal
 primary production and upwelling events. Blacksmiths were exposed to three
 treatments: control (pH ~7.92; pCO<sub>2</sub> ~540 μatm);
 constant acidification (pH ~7.72; pCO<sub>2</sub> ~920 μatm);
 and oscillating acidification (pH ~7.92, pCO<sub>2</sub> ~560
 μatm (day), pH ~7.75, pCO<sub>2</sub> ~955 μatm (night)).
 After seven and eleven days, respectively, blacksmiths were administered
 individual light/dark preference and group shoaling tests, which are
 well-validated measures of anxiety-like behaviour and are modulated by
 GABA<sub>A</sub> receptors. In addition, to investigate
 potential interactions between OA and season of the year, the effect of
 CO<sub>2</sub>/pH on individual blacksmith behaviour was
 tested in January (16.50 ± 0.01<sup>o</sup>C) and September
 (23.10 ± 0.01 <sup>o</sup>C). While season had a significant
 effect on light/dark preference, oscillating acidification did not affect
 any behavioural parameter, suggesting blacksmiths are tolerant to
 projected future OA conditions.