Temperature is the evil twin: Effects of increased temperature and ocean acidification on reproduction in a reef fish

• Main Authors: Miller, Garielle M, Kroon, F J, Metcalfe, Sarah, Munday, Philip L
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: Alkalinity; total; standard error; Amphiprion melanopus; Animalia; Aragonite saturation state; 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; Clutches; survived to hatching; Clutches per month; Clutches per pair; Coast and continental shelf; Condition index; Containers and aquaria (20-1000 L or < 1 m**2); Eggs area; Eggs per clutch; Eggs survived to hatching; Figure; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gonadosomatic index; Hatchling length; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.836664; https://doi.org/10.1594/PANGAEA.836664

Reproduction in many organisms can be disrupted by changes to the physical environment, such as those predicted to occur during climate change. Marine organisms face the dual climate change threats of increasing temperature and ocean acidification, yet no studies have examined the potential interactive effects of these stressors on reproduction in marine fishes. We used a long-term experiment to test the interactive effects of increased temperature and CO2 on the reproductive performance of the anemonefish, Amphiprion melanopus. Adult breeding pairs were kept for 10 months at three temperatures, 28.5°C (+0.0°C), 30.0°C (+1.5°C) and 31.5°C (+3.0°C), cross-factored with 3 CO2 levels, a current day control (417 µatm) and moderate (644 µatm) and high (1134 µatm) treatments consistent with the range of CO2 projections for the year 2100 under RCP8.5. We recorded each egg clutch produced during the breeding season, the number of eggs laid per clutch, average egg size, fertilization success, survival to hatching, hatchling length and yolk provisioning. Adult body condition, hepatosomatic index, gonadosomatic index, and plasma 17beta-estradiol concentrations were measured at the end of the breeding season to determine the effect of prolonged exposure to increased temperature and elevated CO2 on adults, and to examine potential physiological mechanisms for changes in reproduction. Temperature had by far the stronger influence on reproduction, with clear declines in reproduction occurring in the +1.5°C treatment and ceasing altogether in the +3.0°C treatment. In contrast, CO2 had a minimal effect on the majority of reproductive traits measured, but caused a decline in offspring quality in combination with elevated temperature. We detected no significant effect of temperature or CO2 on adult body condition or hepatosomatic index. Elevated temperature had a significant negative effect on plasma 17beta-estradiol concentrations, suggesting that declines in reproduction with increasing temperature were due to the thermal ...