Bell James B, Woulds Clare, Oevelen Dick van
School of Geography, University of Leeds, Leeds, LS2 9JT, UK.
Life Sciences, Natural History Museum, Cromwell Rd, London, SW7 5BD, UK.
Sci Rep. 2017 Sep 20;7(1):12025. doi: 10.1038/s41598-017-12291-w.
Hydrothermal vents are highly dynamic ecosystems and are unusually energy rich in the deep-sea. In situ hydrothermal-based productivity combined with sinking photosynthetic organic matter in a soft-sediment setting creates geochemically diverse environments, which remain poorly studied. Here, we use comprehensive set of new and existing field observations to develop a quantitative ecosystem model of a deep-sea chemosynthetic ecosystem from the most southerly hydrothermal vent system known. We find evidence of chemosynthetic production supplementing the metazoan food web both at vent sites and elsewhere in the Bransfield Strait. Endosymbiont-bearing fauna were very important in supporting the transfer of chemosynthetic carbon into the food web, particularly to higher trophic levels. Chemosynthetic production occurred at all sites to varying degrees but was generally only a small component of the total organic matter inputs to the food web, even in the most hydrothermally active areas, owing in part to a low and patchy density of vent-endemic fauna. Differences between relative abundance of faunal functional groups, resulting from environmental variability, were clear drivers of differences in biogeochemical cycling and resulted in substantially different carbon processing patterns between habitats.
热液喷口是高度动态的生态系统，在深海中能量异常丰富。在软沉积物环境中，基于热液的原位生产力与下沉的光合有机物质相结合，创造了地球化学上多样的环境，但对此研究仍很不足。在这里，我们利用一套全面的新的和现有的实地观测数据，构建了一个来自已知最南端热液喷口系统的深海化学合成生态系统的定量生态模型。我们发现，在布兰斯菲尔德海峡的喷口处及其他地方，化学合成生产为后生动物食物网提供了补充。携带内共生体的动物群在支持化学合成碳向食物网的转移，特别是向更高营养级的转移方面非常重要。化学合成生产在所有地点都有不同程度的发生，但即使在热液活动最活跃的区域，它通常也只是食物网总有机物质输入的一小部分，部分原因是喷口特有动物群的密度较低且分布不均。由环境变异性导致的动物功能群相对丰度差异，是生物地球化学循环差异的明显驱动因素，并导致不同栖息地之间的碳处理模式存在显著差异。
