Antarctica's ecological isolation will be broken by storm-driven dispersal and warming
Antarctica's ecological isolation will be broken by storm-driven dispersal and warming
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DOI：
10.1038/s41558-018-0209-7
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发表时间：
2018-08-01
影响因子：
30.7
通讯作者：
Waters, Jonathan M.
中科院分区：
文献类型：
--
作者：
Fraser, Ceridwen, I;Morrison, Adele K.;Waters, Jonathan M.
长期以来，南极洲一直被认为是生物上孤立的。全球变暖将使南极洲的部分地区更适合入侵类群的居住，但人们认为扩散的障碍——尤其是南大洋强大的环极风、洋流和锋面——可以保护该地区免受来自北方的非人为殖民化(1,2)。我们结合分子和海洋学工具来直接测试整个南大洋的生物扩散。基因组分析表明，漂流的关键海带最近移动了超过 20,000 公里，并跨越了几个海滨“障碍”，从中纬度源种群到达南极洲。高分辨率海洋环流模型结合了中尺度涡流和波浪驱动的斯托克斯漂移，表明这种南极入侵非常频繁和迅速。我们的结果表明，风暴迫使的表面波浪和海洋涡流可以显着增强表层漂移粒子的海洋学连通性，并表明南极洲并不是生物上孤立的。我们推断，南极洲长期存在的生态差异是极端环境的结果，这些极端环境阻碍了适应温带的类群的建立，但这些类群仍然经常分散到该地区。因此，全球变暖有可能允许多种新物种的建立，其中包括将彻底改变生态系统动态的关键海带，即使没有人为引入。
Antarctica has long been considered biologically isolated'. Global warming will make parts of Antarctica more habitable for invasive taxa, yet presumed barriers to dispersal-especially the Southern Ocean's strong, circumpolar winds, ocean currents and fronts-have been thought to protect the region from non-anthropogenic colonizations from the north(1,2). We combine molecular and oceanographic tools to directly test for biological dispersal across the Southern Ocean. Genomic analyses reveal that rafting keystone kelps recently travelled >20,000 km and crossed several ocean-front 'barriers' to reach Antarctica from mid-latitude source populations. High-resolution ocean circulation models, incorporating both mesoscale eddies and wave-driven Stokes drift, indicate that such Antarctic incursions are remarkably frequent and rapid. Our results demonstrate that storm-forced surface waves and ocean eddies can dramatically enhance oceanographic connectivity for drift particles in surface layers, and show that Antarctica is not biologically isolated. We infer that Antarctica's long-standing ecological differences have been the result of environmental extremes that have precluded the establishment of temperate-adapted taxa, but that such taxa nonetheless frequently disperse to the region. Global warming thus has the potential to allow the establishment of diverse new species-including keystone kelps that would drastically alter ecosystem dynamics-even without anthropogenic introductions.