The effects of ocean acidification on ecosystems remain poorly understood, because it is difficult to simulate the effects of elevated CO₂ on entire marine communities. Natural systems enriched in CO₂ are being used to help understand the long-term effects of ocean acidification in situ. Here, we compared biofilm bacterial communities on intertidal cobbles/boulders and bedrock along a seawater CO₂ gradient off Japan. Samples sequenced for 16S rRNA showed differences in bacterial communities with different pCO₂ and between habitat types. In both habitats, bacterial diversity increased in the acidified conditions. Differences in pCO₂ were associated with differences in the relative abundance of the dominant phyla. However, despite the differences in community composition, there was no indication that these changes would be significant for nutrient cycling and ecosystem function. As well as direct effects of seawater chemistry on the biofilm, increased microalgal growth and decreased grazing may contribute to the shift in bacterial composition at high CO₂, as documented by other studies. Thus, the effects of changes in bacterial community composition due to globally increasing pCO₂ levels require further investigation to assess the implications for marine ecosystem function. However, the apparent lack of functional shifts in biofilms along the pCO₂ gradient is a reassuring indicator of stability of their ecosystem functions in shallow ocean margins.

海洋酸化对生态系统的影响仍然知之甚少，因为很难模拟升高的CO ₂对整个海洋群落的影响。富含CO _2的自然系统正在用于帮助了解原位海洋酸化的长期影响。在这里，我们比较了沿日本沿海海水CO ₂梯度的潮间卵石/巨石和基岩上的生物膜细菌群落。对16S rRNA进行测序的样品显示，具有不同p CO _2的细菌群落和生境类型之间存在差异。在两个生境中，在酸化条件下细菌多样性都增加了。p CO _2的差异与优势种的相对丰度的差异有关。然而，尽管社区组成有所不同，但没有迹象表明这些变化对于养分循环和生态系统功能将是重要的。正如其他研究所证明的那样，除了海水化学作用对生物膜的直接影响之外，微藻生长的增加和放牧的减少也可能导致高CO _2下细菌组成的变化。因此，由于全球p CO ₂水平的提高而引起的细菌群落组成变化的影响需要进一步研究，以评估其对海洋生态系统功能的影响。然而，沿p CO _2的生物膜明显缺乏功能转移 梯度是浅海边缘其生态系统功能稳定的令人放心的指标。