Seawater carbonate chemistry and calcification during incubation experiments with Mytilus edulis and Grassostrea gigas, 2006

Ocean acidification resulting from human emissions of carbon dioxide has already lowered and will further lower surface ocean pH. The consequent decrease in calcium carbonate saturation potentially threatens calcareous marine organisms. Here, we demonstrate that the calcification rates of the edible mussel (Mytilus edulis) and Pacific oyster (Crassostrea gigas) decline linearly with increasing pCO2. Mussel and oyster calcification may decrease by 25 and 10%, respectively, by the end of the century, following the IPCC IS92a scenario (?740 ppmv in 2100). Moreover, mussels dissolve at pCO2 values exceeding a threshold value of ?1800 ppmv. As these two species are important ecosystem engineers in coastal ecosystems and represent a large part of worldwide aquaculture production, the predicted decrease of calcification in response to ocean acidification will probably have an impact on coastal biodiversity and ecosystem functioning as well as potentially lead to significant economic loss.

由人类活动排放二氧化碳引发的海洋酸化 (ocean acidification) 现已降低且未来还将持续降低海洋表层pH值。随之而来的碳酸钙饱和度 (calcium carbonate saturation) 下降，或对钙化海洋生物 (calcareous marine organisms) 构成潜在威胁。本研究证实，可食用贻贝 (Mytilus edulis) 与太平洋牡蛎 (Crassostrea gigas) 的钙化速率 (calcification rates) 随二氧化碳分压 (pCO2) 升高呈线性下降趋势。按照政府间气候变化专门委员会 (IPCC) IS92a情景，预计2100年大气二氧化碳浓度约为740ppmv，到本世纪末，贻贝与牡蛎的钙化率或将分别下降25%与10%。此外，当二氧化碳分压超过约1800ppmv的阈值时，贻贝会出现溶解现象。由于这两个物种是沿海生态系统中的重要生态系统工程师 (ecosystem engineers)，且在全球水产养殖产量 (aquaculture production) 中占据较大份额，海洋酸化引发的钙化率下降预测结果，或对沿海生物多样性 (coastal biodiversity) 与生态系统功能 (ecosystem functioning) 产生影响，并可能造成显著的经济损失。