Abundance and characteristics of Polychaeta taxa and associated sediment during POLARSTERN campaign ANT-XXII/3 (ANDEEP-IIII)

During the austral summer of 2005, the Weddell deep sea and adjacent basins were sampled in the course of the ANDEEP III project. In this study, 19 epibenthic-sledge stations are analyzed, with a focus on species diversity and distribution patterns of polychaetes. The polychaete fauna of the deep Southern Ocean has been found to be similarly speciose and diverse compared with deep-sea basins worldwide. Also, in depths below 2,000 m many polychaete species do not seem to be endemic for certain areas but are rather far spread within the Southern Ocean and beyond. Therefore, ongoing faunal exchanges between adjacent basins, even beyond the Antarctic convergence, are strongly suggested, ruling out a general isolation of the Southern Ocean deep-sea benthos. Driving forces behind species distribution patterns were investigated. The findings indicate that polychaete species' distribution in the Southern Ocean deep sea is rather dependent on local environment than depths.

2005年南极夏季期间，ANDEEP III项目对威德尔深海及毗邻盆地开展了采样作业。本研究对19个底上拖网（epibenthic-sledge）站位进行分析，重点聚焦多毛类环节动物（polychaetes）的物种多样性与分布格局。研究发现，南大洋深海的多毛类动物区系，其物种丰富度与多样性水平与全球其他深海盆地相当。此外，在2000米以下的水深环境中，多数多毛类物种并非某一区域的特有种，而是广泛分布于南大洋乃至更广海域。据此可推断，相邻盆地间（甚至跨越南极辐合带）存在持续的动物区系交流，这排除了南大洋深海底栖生物普遍隔离的可能性。本研究还探讨了物种分布格局的驱动因素，结果表明，南大洋深海多毛类的分布更多依赖局地环境，而非水深条件。