Abstract More than 30 cold seeps have been discovered on the northern continental slope of the South China Sea (SCS), but only two cold seep sites actively harbor living cold seep communities. One is the Haima cold seep, which is located at a water depth of approximately 1360–1400 m at the northern slope of the SCS. To date, however, the scale of seepage activity, the spatial distribution of seepages, and the biodiversity of benthic fauna associated with this field remain largely unknown because of the absence of a high-resolution seafloor investigation. Here, we report the spatial distribution of individual seepage areas within the Haima cold seep field and their associated biological community structures. Huge gas flares 100 to 200 m inwidth and ascending ~200–800 m into the water column were identified. Seventeen dives conducted by the manned submersible Shenhaiyongshi showed that the Haima consists of at least six individual patch of communities and(or) carbonate mound (HM-1 to HM-6). Outcrops of gas hydrates were observed at HM-3, where active seepage causes dense seep communities to flourish. We found that Mytilidae and Vesicormyidae were predominant, together with Ophiuridae, Chiridotidae, Siboglinidae, Turridae, Actinernidae, Galatheidae, Alvinocarididae, and Lithodidae. Spatially varying patterns of the Haima fauna are attributed to the supply of methane and sulfides, which could provide useful information regarding dynamical seep change and the carbon and sulfur cycles of cold seep areas.

中文翻译：

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南海海马冷渗场渗流及相关生物群落空间分布

摘要 南海北部大陆坡（SCS）已发现30多处冷泉，但仅有2处冷泉活跃地存在冷泉群落。一是海马冷泉，位于南海北坡水深约1360～1400m处。然而，迄今为止，由于缺乏高分辨率海底调查，渗流活动的规模、渗流的空间分布以及与该领域相关的底栖动物群的生物多样性在很大程度上仍然未知。在这里，我们报告了海马冷渗场内各个渗流区的空间分布及其相关的生物群落结构。确定了宽度为 100 至 200 m 并上升约 200-800 m 进入水体的巨大气体火炬。载人潜水器“神海永世”号进行的 17 次潜水表明，海马由至少 6 个独立的群落和（或）碳酸盐丘（HM-1 至 HM-6）组成。在 HM-3 观察到天然气水合物的露头，活跃的渗流导致密集的渗流群落蓬勃发展。我们发现螳螂科和丝虫科占主导地位，其他还有蛇蝎科、千鸟科、丝虫科、鹳科、猕猴桃科、加拉鱼科、燕尾蛾科和石蛾科。海马动物群的空间变化模式归因于甲烷和硫化物的供应，这可以提供有关动态渗流变化和冷渗区碳和硫循环的有用信息。在 HM-3 观察到天然气水合物的露头，活跃的渗流导致密集的渗流群落蓬勃发展。我们发现螳螂科和丝虫科占主导地位，其他还有蛇蝎科、千鸟科、丝虫科、鹳科、猕猴桃科、加拉鱼科、燕尾蛾科和石蛾科。海马动物群的空间变化模式归因于甲烷和硫化物的供应，这可以提供有关动态渗流变化和冷渗区碳和硫循环的有用信息。在 HM-3 观察到天然气水合物的露头，活跃的渗流导致密集的渗流群落蓬勃发展。我们发现螳螂科和丝虫科占主导地位，其他还有蛇蝎科、千鸟科、丝虫科、鹳科、猕猴桃科、加拉鱼科、燕尾蛾科和石蛾科。海马动物群的空间变化模式归因于甲烷和硫化物的供应，这可以提供有关动态渗流变化和冷渗区碳和硫循环的有用信息。