University of California Santa Cruz, Ecology and Evolutionary Biology, 130 McAllister Way, Santa Cruz, California, 95060, USA.
Moss Landing Marine Laboratories, San Jose State University, 8272 Moss Landing Rd, Moss Landing, California, 95039, USA.
J Phycol. 2022 Aug;58(4):517-529. doi: 10.1111/jpy.13272. Epub 2022 Jul 2.
Global climate changes, such as warming and ocean acidification (OA), are likely to negatively impact calcifying marine taxa. Abundant and ecologically important coralline algae may be particularly susceptible to OA; however, multi-stressor studies and those on articulated morphotypes are lacking. Here, we use field observations and laboratory experiments to elucidate the impacts of warming and acidification on growth, calcification, mineralogy, and photophysiology of the temperate articulated coralline alga, Calliarthron tuberculosum. We conducted a 4-week fully factorial mesocosm experiment exposing individuals from a southern CA kelp forest to current and future temperature and pH/pCO conditions (+2°C, -0.5 pH units). Calcification was reduced under warming (70%) and further reduced by high pCO or high pCO x warming (~150%). Growth (change in linear extension and surface area) was reduced by warming (40% and 50%, respectively), high pCO (20% and 40%, respectively), and high pCO x warming (50% and 75%, respectively). The maximum photosynthetic rate (P ) increased by 100% under high pCO conditions, but we did not detect an effect of pCO or warming on photosynthetic efficiency (α). We also did not detect the effect of warming or pCO on mineralogy. However, variation in Mg incorporation in cell walls of different cell types (i.e., higher mol % Mg in cortical vs. medullary) was documented for the first time in this species. These results support findings from a growing body of literature suggesting that coralline algae are often more negatively impacted by warming than OA, with the potential for antagonistic effects when factors are combined.
全球气候变化，如变暖与海洋酸化（OA），可能会对钙化海洋生物产生负面影响。丰富且生态重要的珊瑚藻可能特别容易受到 OA 的影响；然而，目前缺乏多压力因素研究和关节形态研究。在这里，我们使用野外观察和实验室实验来阐明变暖与酸化对温带关节珊瑚藻 Calliarthron tuberculosum 的生长、钙化、矿物学和光生理的影响。我们进行了为期 4 周的完全因子中尺度实验，使来自加利福尼亚南部海藻林的个体暴露于当前和未来的温度和 pH/pCO 条件下（+2°C，-0.5 pH 单位）。在变暖条件下（70%），钙化减少，高 pCO 或高 pCO x 变暖（~150%）进一步减少钙化。生长（线性延伸和表面积的变化）因变暖（分别减少 40%和 50%）、高 pCO（分别减少 20%和 40%）和高 pCO x 变暖（分别减少 50%和 75%）而减少。在高 pCO 条件下，最大光合作用率（P ）增加了 100%，但我们没有检测到 pCO 或变暖对光合作用效率（α）的影响。我们也没有检测到变暖或 pCO 对矿物学的影响。然而，不同细胞类型细胞壁中镁的含量（即皮质比髓质中更高的 mol%Mg）的变化首次在该物种中得到证实。这些结果支持越来越多的文献表明，珊瑚藻通常比 OA 更易受到变暖的影响，当因素结合时，可能会产生拮抗作用。
