Sinking Jelly-Carbon Unveils Potential Environmental Variability along a Continental Margin
Sinking Jelly-Carbon Unveils Potential Environmental Variability along a Continental Margin
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下沉的胶凝碳揭示了大陆边缘潜在的环境变化
作者：
M. Lebrato;J. Molinero;J. Cartes;D. Lloris;F. Mélin;L. Beni
颗粒物出口为大陆边缘和深海的底栖生态系统提供燃料，从上层海洋中去除碳。胶状浮游动物生物量提供了一种快速碳载体，但研究较少。1994年至2005年大规模底栖拖网捕捞调查的观测数据为量化地中海整个大陆边缘的水母碳并评估与生物和物理变量的潜在联系提供了独特的机会。在货架、斜坡和峡谷中采集了生物量沉积物，峰值在每拖网1000头以上，在拖网捕捞和整合30,000至175,000平方米的海床后，转化为0.3至1.4毫克立方厘米的现存量。从陆架到峡谷的海底水母-碳的空间分布可以用与NAO事件有关的大气强迫和密集的陆架水级联来解释，这两种现象都来自开阔的地中海。在十年尺度上，我们表明，果冻-碳沉积的时间变异性与水气候变化平行，并且增强的果冻-碳沉积与温度驱动系统有关，其中叶绿素起次要作用。我们的结果强调了胶状基团作为大规模生态系统变化指示器的重要性，其中胶状碳沉积在碳和能量向海底系统的运输中发挥着重要作用。
Particulate matter export fuels benthic ecosystems in continental margins and the deep sea, removing carbon from the upper ocean. Gelatinous zooplankton biomass provides a fast carbon vector that has been poorly studied. Observational data of a large-scale benthic trawling survey from 1994 to 2005 provided a unique opportunity to quantify jelly-carbon along an entire continental margin in the Mediterranean Sea and to assess potential links with biological and physical variables. Biomass depositions were sampled in shelves, slopes and canyons with peaks above 1000 carcasses per trawl, translating to standing stock values between 0.3 and 1.4 mg C m2 after trawling and integrating between 30,000 and 175,000 m2 of seabed. The benthopelagic jelly-carbon spatial distribution from the shelf to the canyons may be explained by atmospheric forcing related with NAO events and dense shelf water cascading, which are both known from the open Mediterranean. Over the decadal scale, we show that the jelly-carbon depositions temporal variability paralleled hydroclimate modifications, and that the enhanced jelly-carbon deposits are connected to a temperature-driven system where chlorophyll plays a minor role. Our results highlight the importance of gelatinous groups as indicators of large-scale ecosystem change, where jelly-carbon depositions play an important role in carbon and energy transport to benthic systems.