CO2-induced ocean acidification increases anxiety in Rockfish via alteration of GABAA receptor functioning

• Main Authors: Hamilton, Trevor James, Holcombe, Adam, Tresguerres, Martin
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Alkalinity; total; standard error; Animalia; Aragonite saturation state; Behaviour; Bicarbonate ion; Calcite saturation state; Calculated using CO2SYS; 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); Distance; Figure; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Immobility; Laboratory experiment; Nekton; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Potentiometric; Salinity; Sebastes diploproa; Single species; Species; Table; Temperate; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.834309; https://doi.org/10.1594/PANGAEA.834309

The average surface pH of the ocean is dropping at a rapid rate due to the dissolution of anthropogenic CO2, raising concerns for marine life. Additionally, some coastal areas periodically experience upwelling of CO2-enriched water with reduced pH. Previous research has demonstrated ocean acidification (OA)-induced changes in behavioural and sensory systems including olfaction, which is due to altered function of neural gamma-aminobutyric acid type A (GABAA) receptors. Here, we used a camera-based tracking software system to examine whether OA-dependent changes in GABAA receptors affect anxiety in juvenile Californian rockfish (Sebastes diploproa). Anxiety was estimated using behavioural tests that measure light/dark preference (scototaxis) and proximity to an object. After one week in OA conditions projected for the next century in the California shore (1125 ± 100 µatm, pH 7.75), anxiety was significantly increased relative to controls (483 ± 40 µatm CO2, pH 8.1). The GABAA-receptor agonist muscimol, but not the antagonist gabazine, caused a significant increase in anxiety consistent with altered Cl- flux in OA-exposed fish. OA-exposed fish remained more anxious even after 7 days back in control seawater; however, they resumed their normal behaviour by day 12. These results show that OA could severely alter rockfish behaviour; however, this effect is reversible.