Sekizawa Ayami, Uechi Hikaru, Iguchi Akira, Nakamura Takashi, Kumagai Naoki H, Suzuki Atsushi, Sakai Kazuhiko, Nojiri Yukihiro
Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan.
Department of Bioresources Engineering, National Institute of Technology, Okinawa College, 905 Henoko, Nago-City, Okinawa 905-2192, Japan.
Mar Pollut Bull. 2017 Sep 15;122(1-2):282-287. doi: 10.1016/j.marpolbul.2017.06.061. Epub 2017 Jun 24.
Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO, respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration.
海洋酸化通过减少钙化作用对海洋钙化生物产生负面影响，这一点已得到广泛认可，但对于这些生物是否能够在一定的表型可塑性范围内应对海洋酸化和/或适应未来酸化的海洋，仍存在争议。我们使用常见的分支珊瑚指状蔷薇珊瑚和柱形鹿角珊瑚的克隆片段，在对照海水和酸化海水（较低pH值）条件下（分别约为400和900μatm pCO₂）进行了实验室饲养实验，并评估了它们对海洋酸化反应的种内变异。根据pCO₂条件和珊瑚群体的不同，钙化作用和光合效率的种内和种间变异都很明显，这表明在群体水平上，对酸化的反应可能存在个体差异。我们的结果表明，一些珊瑚可能通过表型可塑性进行适应，在其当前的基因型组成范围内应对海洋酸化，而另一些珊瑚可能会面临选择压力，导致种群变化。
