Biogeochemistry of the Darwin Mounds, NE Atlantic

The Darwin Mounds are a series of small (<=5 m high, 75-100 m diameter) sandy features located in the northern Rockall Trough. They provide a habitat for communities of Lophelia pertusa and associated fauna. Suspended particulate organic matter (sPOM) reaching the deep-sea floor, which could potentially fuel this deep-water coral (DWC) ecosystem, was collected during summer 2000. This was relatively "fresh" (i.e. dominated by labile lipids such as polyunsaturated fatty acids) and was derived largely from phytoplankton remains and faecal pellets, with contributions from bacteria and microzooplankton. Labile sPOM components were enriched in the benthic boundary layer (~10 m above bottom (mab)) relative to 150 mab. The action of certain benthic fauna that are exclusively associated with the DWC ecosystem (e.g. echiuran worms) leads to the subduction of fresh organic material into the sediments. The mound surface sediments are enriched in organic carbon, relative to off-mound sites. […]

达尔文丘群是一系列小型（高度不超过5米，直径75-100米）的沙质地貌，位于洛克勒尔海槽北部。这些地貌为（Lophelia pertusa）珊瑚及其相关生物群落提供了栖息地。在2000年夏季，收集了悬浮的颗粒有机物质（sPOM），这些物质抵达深海底部，可能为该深海珊瑚（DWC）生态系统提供能量来源。这些物质相对较“新鲜”（即主要由易变的脂类，如多不饱和脂肪酸）组成，主要来源于浮游植物残骸和粪便球粒，细菌和微型浮游动物亦有所贡献。与底部150米相比，易变的sPOM成分在海底边界层（距底部约10米，mab）中富集。某些与深海珊瑚生态系统（例如，鳃鳃类蠕虫）唯一相关联的底栖生物群的活动，导致新鲜有机物质被推移入沉积物中。与丘群外缘的地点相比，丘群表面的沉积物富含有机碳。