Data from: Ocean acidification affects fish spawning but not paternity at CO2 seeps

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.

在本世纪因人为二氧化碳排放（anthropogenic carbon dioxide emissions）预计会出现的海洋酸化（ocean acidification）水平下，鱼类会出现感知功能受损与行为改变的现象。本研究首次提供了海洋酸化对野生鱼类繁殖行为产生影响的野外证据。眼斑濑鱼（ocellated wrasse，Symphodus ocellatus）的卫星雄鱼（satellite male）与偷袭雄鱼（sneaker male）会竞争受精于由占优势筑巢雄鱼所守护的鱼卵。诸如占优势雄鱼求偶与巢穴防御这类关键交配行为，在环境二氧化碳浓度与升高二氧化碳浓度的采样位点之间并未表现出显著差异。但占优势雄鱼在升高的二氧化碳浓度环境中，其配对产卵的发生率显著更低。尽管在升高的二氧化碳浓度环境下，精子竞争的风险有所升高，但我们同样发现卫星雄鱼与偷袭雄鱼的父权占比呈现出降低的趋势。鉴于鱼类对粮食安全与生态系统稳定的重要意义，本研究强调了针对二氧化碳水平升高对野生鱼类繁殖模式的影响开展定向研究的必要性。