Eighty-five million years of Pacific Ocean gyre ecosystem structure: long-term stability marked by punctuated change
Eighty-five million years of Pacific Ocean gyre ecosystem structure: long-term stability marked by punctuated change
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八千五百万年的太平洋环流生态系统结构：以间断变化为特征的长期稳定性
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
L. Graves
中科院分区：
文献类型：
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作者：
E. Sibert;R. Norris;J. Cuevas;L. Graves
虽然在公海的鳍鱼和板鳃类谱系的分类多样化的历史越来越多的人知道，他们在公海生态系统中的作用的演变仍然知之甚少。为了评估这些群体随着时间的推移的相对重要性，我们测量了过去8500万年（百万年）以来北太平洋和南太平洋环流深海沉积物岩心中微化石鱼牙齿和板鳃类真皮层（鱼化石）的积累率。我们发现三个不同的和稳定的开放的海洋生态系统结构，每个定义的相对和绝对丰度的板鳃类和鳍鱼遗骸。白垩纪海洋（前66马）的特点是丰富的板鳃类的密集，但低丰度的鱼类牙齿。由白垩纪/古近纪生物大灭绝引发的古近纪海洋（66-20 Ma），其鱼类牙齿的丰度几乎是板鳃类的四倍。这种古近纪海洋结构在始新世温室（50 Ma）和始新世-渐新世冰期（34 Ma）期间保持稳定，尽管在这些间隔期间这两个群体的总体积累发生了很大变化，这表明气候变化不是生态系统结构的主要驱动力。大约在20 Ma左右，深海鱼化石组合中的真皮齿垢几乎消失了，而鱼牙齿的积累在变异性上急剧增加，标志着现代海洋的开始。总之，这些结果表明，开放的海洋鱼类群落结构在长时间尺度上是稳定的，不受总产量和气候变化的影响。这些状态之间的突然转变的时间表明，这种转变可能是由于与其他非保护远洋消费群体的相互作用。
While the history of taxonomic diversification in open ocean lineages of ray-finned fish and elasmobranchs is increasingly known, the evolution of their roles within the open ocean ecosystem remains poorly understood. To assess the relative importance of these groups through time, we measured the accumulation rate of microfossil fish teeth and elasmobranch dermal denticles (ichthyoliths) in deep-sea sediment cores from the North and South Pacific gyres over the past 85 million years (Myr). We find three distinct and stable open ocean ecosystem structures, each defined by the relative and absolute abundance of elasmobranch and ray-finned fish remains. The Cretaceous Ocean (pre-66 Ma) was characterized by abundant elasmobranch denticles, but low abundances of fish teeth. The Palaeogene Ocean (66–20 Ma), initiated by the Cretaceous/Palaeogene mass extinction, had nearly four times the abundance of fish teeth compared with elasmobranch denticles. This Palaeogene Ocean structure remained stable during the Eocene greenhouse (50 Ma) and the Eocene–Oligocene glaciation (34 Ma), despite large changes in the overall accumulation of both groups during those intervals, suggesting that climate change is not a primary driver of ecosystem structure. Dermal denticles virtually disappeared from open ocean ichthyolith assemblages approximately 20 Ma, while fish tooth accumulation increased dramatically in variability, marking the beginning of the Modern Ocean. Together, these results suggest that open ocean fish community structure is stable on long timescales, independent of total production and climate change. The timing of the abrupt transitions between these states suggests that the transitions may be due to interactions with other, non-preserved pelagic consumer groups.
影响因子：
5.3
作者：
J. Zachos;H. McCarren;B. Murphy;U. Röhl;T. Westerhold
通讯作者：
J. Zachos;H. McCarren;B. Murphy;U. Röhl;T. Westerhold