Evaluation of newly discovered CO2 seeps as potential natural laboratories to study coral reef acclimatization to ocean acidification

由于海水的碳酸盐化学成分可能发生根本性变化，人为二氧化碳吸收造成的海洋酸化可能会对珊瑚礁产生深远的影响。到目前为止，对海洋酸化对珊瑚礁影响的大部分评估都是在实验室条件下的简化系统中进行的。虽然这些研究是重要的和信息丰富的，但它们在自然变异性、持续时间、年龄分布、遗传多样性和几个珊瑚物种的相互作用方面存在局限性。解决这些局限性的一个可能的解决方案是研究海底二氧化碳渗漏附近的珊瑚礁，这会导致海水中二氧化碳水平的增加。因此，到2100年，酸碱度和温度条件应该与预期的相似。现在已经对三个这样的珊瑚礁进行了调查，有趣的是，在巴布亚新几内亚、日本和北马里亚纳群岛的地点，结果都不同。这种差异的一个可能解释是，这些研究存在缺陷，因为没有考虑到对珊瑚礁健康至关重要的所有参数，例如有毒金属含量。一般来说，海底二氧化碳的排放伴随着温度高达100°C的热液，将重金属释放到研究区域。在将二氧化碳排放作为研究海洋酸化的天然实验室时，必须考虑这两种影响。考虑到这一点，该项目的目的是评估印度尼西亚和菲律宾的几个这样的二氧化碳排放，以便评估它们是否可以用作自然实验室，以更好地了解海洋酸化的影响。

Acidification of the oceans through the uptake of anthropogenic CO2 could have far-reaching effects on coral reefs, since the carbonate chemistry of seawater can undergo fundamental changes. Until now, much of the assessment of the impact of ocean acidification on coral reefs has been carried out in simplified systems under laboratory conditions. While these studies were crucial and informative, they have limitations in terms of natural variability, duration, age distribution, genetic diversity and the interaction of several coral species. One possible solution to these limitations is to study coral reefs in the vicinity of submarine CO2 seeps, which cause increased CO2 levels in seawater. Accordingly, the pH and temperature conditions should be similar to those expected by 2100. Three such coral reefs have now been investigated and, interestingly, the results were all different at the sites in Papua New Guinea, Japan and the Northern Mariana Islands. One possible explanation for this discrepancy is that these studies were flawed in that not all parameters important for the health of the coral reefs were considered, such as toxic metal content. In general, submarine CO2 discharges are accompanied by hydrothermal fluids with temperatures up to 100 °C, which release heavy metals into the study area. These are two effects that have to be considered when using CO2 discharges as natural laboratories for the study of ocean acidification. With this in mind, the aim of this project is to assess several such CO2-emissions in Indonesia and the Philippines, in order to evaluate whether they can be used as natural laboratories to better understand the effects of ocean acidification.