Ocean acidification affects fish spawning but not paternity at CO2 seeps

• Main Authors: Milazzo, Marco, Cattano, Carlo, Alonzo, Suzanne H, Foggo, A, Gristina, Michele, Rodolfo-Metalpa, Riccardo, Sinopoli, Mauro, Spatafora, Davide, Stiver, Kelly A, Hall-Spencer, Jason M
• Format: Dataset
• Language: English
• Published: PANGAEA 2016
• Subjects: Age; Alkalinity; total; Animalia; Aragonite saturation state; Behaviour; Bicarbonate ion; Cala_Isola; 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; CO2 vent; Coast and continental shelf; Courtship; standard error; Dominant male paternity; Eggs; Eggs area; Event label; EXP; Experiment; Field observation; Fish; standard length; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Identification; Individuals; Location; Mediterranean Sea; Nekton; Number; Number of individuals; Number of spawning events; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.867446; https://doi.org/10.1594/PANGAEA.867446

Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification expected to occur owing to anthropogenic carbon dioxide emissions during this century. We provide the first evidence of the effects of ocean acidification on reproductive behaviour of fish in the wild. Satellite and sneaker male ocellated wrasse (Symphodus ocellatus) compete to fertilize eggs guarded by dominant nesting males. Key mating behaviours such as dominant male courtship and nest defence did not differ between sites with ambient versus elevated CO2 concentrations. Dominant males did, however, experience significantly lower rates of pair spawning at elevated CO2 levels. Despite the higher risk of sperm competition found at elevated CO2, we also found a trend of lower satellite and sneaker male paternity at elevated CO2. Given the importance of fish for food security and ecosystem stability, this study highlights the need for targeted research into the effects of rising CO2 levels on patterns of reproduction in wild fish.