Norwegian Polar Institute, Tromsø, Norway.
Department of Biological and Environmental Sciences, University of Gothenburg, Fiskebäckskil, Sweden.
Glob Chang Biol. 2018 Jan;24(1):e365-e377. doi: 10.1111/gcb.13870. Epub 2017 Sep 21.
Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognized as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid-base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across geographically separated populations of the keystone Arctic copepod Calanus glacialis. In copepodites stage CIV, measured reaction norms of ingestion rate and metabolic rate showed severe reductions in ingestion and increased metabolic expenses in two populations from Svalbard (Kongsfjord and Billefjord) whereas no effects were observed in a population from the Disko Bay, West Greenland. At pH 7.87, which has been predicted for the Svalbard west coast by year 2100, these changes resulted in reductions in scope for growth of 19% in the Kongsfjord and a staggering 50% in the Billefjord. Interestingly, these effects were not observed in stage CV copepodites from any of the three locations. It seems that CVs may be more tolerant to OA perhaps due to a general physiological reorganization to meet low intracellular pH during hibernation. Needless to say, the observed changes in the CIV stage will have serious implications for the C. glacialis population health status and growth around Svalbard. However, OA tolerant populations such as the one in the Disko Bay could help to alleviate severe effects in C. glacialis as a species.
广泛的海洋酸化（OA）正在改变全球海洋的化学性质，北极被认为是变化将以最快速度推进的区域。此外，北极物种的细胞内稳态和酸碱调节能力较低，使它们特别容易受到 OA 的影响。在本研究中，我们发现了地理上分离的北极关键桡足类 Calanus glacialis 种群对 OA 反应的生理差异。在桡足幼体阶段 CIV 中，测量的摄食率和代谢率反应规范显示，来自斯瓦尔巴群岛（康斯峡湾和比列弗峡湾）的两个种群的摄食严重减少，代谢费用增加，而在来自格陵兰岛西海岸迪斯科湾的种群中则没有观察到这些影响。在 pH7.87 的条件下，预计到 2100 年斯瓦尔巴群岛西海岸的 pH 值将达到这个水平，这些变化导致康斯峡湾的生长范围缩小了 19%，而比列弗峡湾的生长范围则缩小了 50%。有趣的是，在来自这三个地点的任何一个地点的 CV 阶段桡足幼体中都没有观察到这些影响。似乎 CV 可能对 OA 更具耐受性，也许是由于在冬眠期间为满足低细胞内 pH 值而进行的一般生理重组。不用说，在斯瓦尔巴群岛周围的 C. glacialis 种群健康状况和生长方面，观察到的 CIV 阶段的变化将产生严重影响。然而，像迪斯科湾那样的耐 OA 种群可能有助于缓解 C. glacialis 作为一个物种的严重影响。
