Takao Shintaro, Kumagai Naoki H, Yamano Hiroya, Fujii Masahiko, Yamanaka Yasuhiro
Faculty of Environmental Earth Science, Hokkaido University North 10 West 5, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.
Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
Ecol Evol. 2015 Jan;5(1):213-23. doi: 10.1002/ece3.1358. Epub 2014 Dec 18.
Seaweed beds play a key role in providing essential habitats and energy to coastal areas, with enhancements in productivity and biodiversity and benefits to human societies. However, the spatial extent of seaweed beds around Japan has decreased due to coastal reclamation, water quality changes, rising water temperatures, and heavy grazing by herbivores. Using monthly mean sea surface temperature (SST) data from 1960 to 2099 and SST-based indices, we quantitatively evaluated the effects of warming seawater on the spatial extent of suitable versus unsuitable habitats for temperate seaweed Ecklonia cava, which is predominantly found in southern Japanese waters. SST data were generated using the most recent multiple climate projection models and emission scenarios (the Representative Concentration Pathways or RCPs) used in the Coupled Model Intercomparison Project phase 5 (CMIP5). In addition, grazing by Siganus fuscescens, an herbivorous fish, was evaluated under the four RCP simulations. Our results suggest that continued warming may drive a poleward shift in the distribution of E. cava, with large differences depending on the climate scenario. For the lowest emission scenario (RCP2.6), most existing E. cava populations would not be impacted by seawater warming directly but would be adversely affected by intensified year-round grazing. For the highest emission scenario (RCP8.5), previously suitable habitats throughout coastal Japan would become untenable for E. cava by the 2090s, due to both high-temperature stress and intensified grazing. Our projections highlight the importance of not only mitigating regional warming due to climate change, but also protecting E. cava from herbivores to conserve suitable habitats on the Japanese coast.
海藻床在为沿海地区提供重要栖息地和能量方面发挥着关键作用，有助于提高生产力和生物多样性，并造福人类社会。然而，由于沿海填海、水质变化、水温上升以及食草动物的过度啃食，日本周边海藻床的空间范围已经缩小。利用1960年至2099年的月平均海表温度（SST）数据和基于SST的指数，我们定量评估了海水变暖对温带海藻裙带菜适宜和不适宜栖息地空间范围的影响，裙带菜主要分布在日本南部海域。SST数据是使用耦合模式比较计划第5阶段（CMIP5）中使用的最新多气候预测模型和排放情景（代表性浓度路径或RCPs）生成的。此外，在四个RCP模拟下评估了食草鱼黄斑篮子鱼的啃食情况。我们的结果表明，持续变暖可能会导致裙带菜分布向极地转移，具体差异取决于气候情景。对于最低排放情景（RCP2.6），大多数现有的裙带菜种群不会直接受到海水变暖的影响，但会受到全年啃食加剧的不利影响。对于最高排放情景（RCP8.5），到2090年代，由于高温胁迫和啃食加剧，日本沿海以前适宜的栖息地将变得不适宜裙带菜生存。我们的预测强调了不仅要缓解气候变化导致的区域变暖，还要保护裙带菜免受食草动物侵害以保护日本海岸适宜栖息地的重要性。
