Long-term history of chemoautotrophic clam-dominated faunas of petroleum seeps in the Northwestern Gulf of Mexico
Long-term history of chemoautotrophic clam-dominated faunas of petroleum seeps in the Northwestern Gulf of Mexico
复制标题
墨西哥湾西北部石油渗漏区以化能自养蛤为主的动物群的长期历史
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
E. Powell
中科院分区：
文献类型：
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作者：
Russell Callender;E. Powell
摘要在墨西哥湾大陆坡，以化能自养蛤类为主的生物组合通常与石油渗漏有关。我们研究的持久性和弹性，这些社区的丰度，生物量和营养动力学从四个独立的石油渗漏点的路易斯安那州大陆坡的社区评估downcore的趋势。一些石油渗漏点在与地质有关的时期内持续为某些物种保留了最佳生境。然而，更常见的是，栖息地优化在数百年的时间尺度上变化很大。因此，这些地点的一个重要特征是化能自养生物群的持久性程度。一个动物群通常在几百年的时间跨度内持续存在，但在更长的时间跨度内通常不持续存在。产生局部灭绝的机制仍不清楚，但少年生存的时间变化似乎是大大大于幼虫定居的时间变化，在一定程度上，严重taphonomically偏见的记录少年个人允许这样的结论。当化能自养生物区系发生局部灭绝时，该生物区系被正常斜坡生物区系或正常斜坡生物区系与未能存活至成年期的化能自养物种幼鱼的混合物所取代。因此，唯一的动物群过渡是在特定的化能自养动物群和非化能自养动物群之间。两个化能自养动物群之间没有一个明显的区系过渡。因此，每个离散的化能自养动物群在很长的时间尺度上是有弹性的;时间尺度的地质意义。
SummaryChemoautotrophic clam-dominated assemblages are commonly associated with petroleum seepage on the continental slope of the Gulf of Mexico. We examine the persistence and resilence of these communities by evaluating downcore trends in abundance, biomass, and trophodynamics in communities from four separate petroleum seep sites on the Louisiana continental slope. Some petroleum seep sites retained optimal habitat for some species continuously over geologically-relevant periods of time. More commonly, however, habitat optimality varied substantially over time scales of hundreds of years. Thus, one important characteristic of these sites was the degree of persistence of the chemoautotrophic biota. A fauna typically was persistent over a time span of a few hundred years, but was typically not persistent over a longer time span. The mechanisms producing local extinction remain unclear, however temporal variations in juvenile survivorship seem to be substantially larger than temporal variations in larval settlement, to the extent that the heavily taphonomically-biased record of juvenile individuals permits such a conclusion. When local extinctions occurred in the chemoautotrophic biota, the biota was replaced by a normal slope biota or a mixture of a normal slope biota and the juveniles of chemoautotrophic species that failed to survive to adulthood. Thus, the only faunal transitions were between specific chemoautotrophic faunas and the non-chemoautotrophic fauna. Not one distinctive faunal transition between two chemoautotrophic faunas was observed. Accordingly, each discrete chemoautotrophic fauna was resilient over long time scales; time scales of geological importance.