Department of Earth Sciences, Laboratory of Palaeobotany and Palynology, Faculty of Geosciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, Netherlands.
Science. 2013 Apr 19;340(6130):341-4. doi: 10.1126/science.1223646.
The circum-Antarctic Southern Ocean is an important region for global marine food webs and carbon cycling because of sea-ice formation and its unique plankton ecosystem. However, the mechanisms underlying the installation of this distinct ecosystem and the geological timing of its development remain unknown. Here, we show, on the basis of fossil marine dinoflagellate cyst records, that a major restructuring of the Southern Ocean plankton ecosystem occurred abruptly and concomitant with the first major Antarctic glaciation in the earliest Oligocene (~33.6 million years ago). This turnover marks a regime shift in zooplankton-phytoplankton interactions and community structure, which indicates the appearance of eutrophic and seasonally productive environments on the Antarctic margin. We conclude that earliest Oligocene cooling, ice-sheet expansion, and subsequent sea-ice formation were important drivers of biotic evolution in the Southern Ocean.
环南极南大洋是全球海洋食物网和碳循环的重要区域，因为这里有海冰的形成和独特的浮游生态系统。然而，这个独特生态系统的形成机制及其发展的地质时间仍然未知。在这里，我们基于化石海洋甲藻孢囊记录表明，浮游生态系统在最早的渐新世（约 3360 万年前）发生了一次重大的结构重组，与第一次主要的南极冰期同时发生。这种转变标志着浮游动物-浮游植物相互作用和群落结构的重大转变，表明在南极边缘出现了富营养化和季节性生产力的环境。我们的结论是，最早的渐新世冷却、冰盖扩张和随后的海冰形成是南大洋生物进化的重要驱动因素。
