Centre National de la Recherche Scientifique-Institut National des Sciences de l'Univers, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-mer, France.
PLoS One. 2013 Apr 30;8(4):e62655. doi: 10.1371/journal.pone.0062655. Print 2013.
Ocean acidification caused by anthropogenic uptake of CO₂ is perceived to be a major threat to calcifying organisms. Cold-water corals were thought to be strongly affected by a decrease in ocean pH due to their abundance in deep and cold waters which, in contrast to tropical coral reef waters, will soon become corrosive to calcium carbonate. Calcification rates of two Mediterranean cold-water coral species, Lophelia pertusa and Madrepora oculata, were measured under variable partial pressure of CO₂ (pCO₂) that ranged between 380 µatm for present-day conditions and 930 µatm for the end of the century. The present study addressed both short- and long-term responses by repeatedly determining calcification rates on the same specimens over a period of 9 months. Besides studying the direct, short-term response to elevated pCO₂ levels, the study aimed to elucidate the potential for acclimation of calcification of cold-water corals to ocean acidification. Net calcification of both species was unaffected by the levels of pCO₂ investigated and revealed no short-term shock and, therefore, no long-term acclimation in calcification to changes in the carbonate chemistry. There was an effect of time during repeated experiments with increasing net calcification rates for both species, however, as this pattern was found in all treatments, there is no indication that acclimation of calcification to ocean acidification occurred. The use of controls (initial and ambient net calcification rates) indicated that this increase was not caused by acclimation in calcification response to higher pCO₂. An extrapolation of these data suggests that calcification of these two cold-water corals will not be affected by the pCO₂ level projected at the end of the century.
人为吸收二氧化碳导致的海洋酸化被认为是对钙化生物的主要威胁。冷水珊瑚由于在深海和冷水中丰富，被认为会受到海洋 pH 值下降的强烈影响，而与热带珊瑚礁水域相比，这些水域很快就会对碳酸钙产生腐蚀性。本研究测量了两种地中海冷水珊瑚（Lophelia pertusa 和 Madrepora oculata）在可变二氧化碳分压（pCO₂）下的钙化率，pCO₂范围从当今条件下的 380 µatm 到本世纪末的 930 µatm。本研究通过在 9 个月的时间内对同一标本反复测定钙化率，既研究了短期反应，也研究了长期反应。除了研究对升高的 pCO₂水平的直接短期反应外，该研究还旨在阐明冷水珊瑚钙化对海洋酸化的适应潜力。两种珊瑚的净钙化均不受所研究的 pCO₂水平的影响，并且没有显示出短期冲击，因此，在钙化适应碳酸盐化学变化方面没有长期的适应。在对两种物种进行的重复实验中，随着时间的推移，出现了净钙化率增加的情况，但是，由于这种模式在所有处理中都存在，因此没有迹象表明钙化对海洋酸化的适应发生了。对照（初始和环境净钙化率）的使用表明，这种增加不是由于对更高 pCO₂的钙化反应的适应引起的。对这些数据的推断表明，这两种冷水珊瑚的钙化不会受到本世纪末预计的 pCO₂水平的影响。
