Chemosynthetically-driven ecosystems south of the Polar Front: biogeography and ecology

我们建议分析极锋以南的南极洲的化学合成生态系统。我们将对四种不同类型的化学合成驱动群落及其区域构造背景进行详细的调查和分析。我们调查的群落包括：与高温裸岩热液喷口有关的群落(东斯科舍海脊)、与高温、沉积物为主的热液活动有关的群落(布兰斯菲尔德海峡)、泥火山(南桑威奇弧前盆地)和甲烷水合物(乔治王岛以北)。我们提出了三次巡航和随后的以实验室为基础的方案。邮轮1号将前往东斯科舍海，在那里我们将检查构造环境，并使用自主水下航行器和热液采样器布里奇特对热液排放进行采样。邮轮2号将前往同一地区，并将使用英国遥控潜水器(ROV)IIS潜水，采样并描述邮轮1中确定的喷口和渗漏地点周围的生物和物理环境。邮轮3将是一次地球物理、化学和生物相结合的邮轮，使用ROV IIS潜水并研究南极乔治王岛北部和南部的热液和冷渗漏环境。随后的分析将比较这四个地点的热液和渗漏化学。我们将使用微生物和后生动物种群的形态、分子、脂肪和稳定同位素分析来确定物种的系统地理，并了解食物网的过程。我们的计划将确定，在这些最孤立的化学合成驱动的生态系统中，喷口和渗漏的殖民是由海洋过程还是构造过程驱动的，或者是否有任何地点是完全孤立的进化的宿主。

We propose an analysis of the chemosynthetic ecosystems in Antarctica south of the Polar Front. We will conduct a detailed investigation and analysis of four contrasting types of chemosynthetically-driven communities, together with their regional tectonic setting. The communities chosen for our investigation comprise: those associated with high-temperature, bare-rock hydrothermal vents (East Scotia Ridge), high-temperature, sediment-hosted hydrothermal activity (Bransfield Strait), mud volcanoes (South Sandwich fore-arc basin) and methane hydrates (north of King George Island). We propose three cruises and subsequent laboratory-based programmes. Cruise 1 will be to the East Scotia Sea where we will examine the tectonic setting and sample the hydrothermal discharge using autonomous underwater vehicles and the hydrothermal sampler BRIDGET. Cruise 2 will be to the same area and will use the UK Remotely Operated Vehicle (ROV) Isis to dive on, sample and characterise the biological and physical environment surrounding vent and seep sites identified during Cruise 1. Cruise 3 will be a combined geophysical, chemical and biological cruise, using the ROV Isis to dive upon and examine hydrothermal and cold seep environments both north and south of King George Island, Antarctic Peninsula. Subsequent analysis will compare the hydrothermal and seep chemistry among these four sites. We will use morphological, molecular, lipid and stable isotope analyses of microbial and metazoan populations to determine the phylogeography of species, and understand the food web processes. Our programme will determine whether colonisation of vents and seeps, in these most isolated of chemosynthetically-driven ecosystems, is driven by oceanographic or tectonic processes or whether any site is, instead, host to completely isolated evolution.