Data from a 3 m sediment core collected west of Pidgeon Island in the Windmill Islands, Antarctica

A sediment core was collected from the western side of Pidgeon Island, (66.3216 S, 110.445 E) at a water depth of 82.0 m. This sediment core (PG 1411-2) was recovered using a release-controlled piston corer, with a length of 3 m, using the coring technique described in Melles et al., (1994). The total core length was 240 cm. This core was stored in the dark, at 0 degrees C until required. Samples were taken for diatom analyses and radiocarbon (14C) dating. Prior to sub-sampling the core was split in half, along its length. One half was used for sampling, the other kept intact and stored at IASOS (University of Tasmania). To reduce potential contamination, resulting from the disturbance of sediments during the core-splitting procedure, a thin layer of sediment was removed from the exposed surface immediately prior to sampling.In order to obtain samples for diatom analysis, a toothpick was inserted into the core segment, and used to gouge a small amount of sediment from the middle of the core. Samples for diatom analyses were initially collected every 5 mm, however, sampling frequency progressively decreased down the core. Samples for radiocarbon data consisted of at least 1 cm 3 of sediment, collected from the middle of the core. These samples were collected from between 0-1 cm, 12-13 cm, 59-60 cm, 77-78 cm, 117-118 cm, and 229-230 cm depth.Diatom data are presented as raw counts, benthic abundances, the ratio of benthic to plankton species, and as the benthic index. Calculated ages (in years) are also given for all samples. The sedimentological core log is given as a powerpoint presentation.This work was completed as part of ASAC project 1130 (ASAC_1130) and project 2201 (ASAC_2201).Public summary from project 1130:Algal mats grow on sea floor in most shallow marine environments. They are thought to contribute more than half of the total primary production in many of these areas, making them a critical food source for invertebrates and some fish. We will establish how important they are in Antarctic marine environments and determine the effects of local sewerage and tip site pollution. We will also investigate the impact on the algal mats of the additional UV radiation which results from the ozone hole.Public summary from project 2201:As a signatory to the Protocol on Environmental Protection to the Antarctic Treaty Australia is committed to comprehensive protection of the Antarctic environment. This protocol requires that activities in the Antarctic shall be planned and conducted on the basis of information sufficient to make prior assessments of, and informed judgements about, their possible impacts on the Antarctic environment. Most of our activities in the Antarctic occur along the narrow fringe of ice-free rock adjacent to the sea and many of our activities have the potential to cause environmental harm to marine life. The Antarctic seas support the most complex and biologically diverse plant and animal communities of the region. However, very little is known about them and there is certainly not sufficient known to make informed judgements about possible environmental impacts.The animals and plants of the sea-bed are widely accepted as being the most appropriate part of the marine ecosystem for indicating disturbance caused by local sources. Attached sea-bed organisms have a fixed spatial relationship with a given place so they must either endure conditions or die. Once lost from a site recolonisation takes some time, as a consequence the structure of sea-bed communities reflect not only present conditions but they can also integrate conditions in the past. In contrast, fish and planktonic organisms can move freely so their site of capture does not indicate a long residence time at that location. Because sea-bed communities are particularly diverse they contain species with widely differing life strategies, as a result different species can have very different levels of tolerance to stress; this leads to a range of subtle changes in community structure as a response to gradually increasing disturbance, rather than an all or nothing response.This project will examine sea-bed communities near our stations to determine how seriously they are affected by human activities. This information will be used to set priorities for improving operational procedures to reduce the risk of further environmental damage.The fields in this dataset are:SpeciesSiteBenthic %Planktonic %Depth (cm)Age (years)Radiocarbon AgeCorrected AgeBenthic Index

研究人员于皮吉恩岛西侧（南纬66.3216°，东经110.445°）、水深82.0米处采集了一根沉积物岩芯。该岩芯编号为PG 1411-2，采用Melles等人1994年报道的取芯技术，通过可控释放活塞式取芯器获取，初始标称长度为3米，实际回收总长度为240厘米。该岩芯全程避光保存于0℃环境中直至实验使用。研究人员分别开展了硅藻分析与放射性碳（14C）定年样品的采集工作。分样前，岩芯沿轴向被对半剖开，一半用于取样分析，另一半完整保存于塔斯马尼亚大学IASOS研究所。为降低岩芯剖开过程中沉积物扰动带来的潜在污染，取样前需即刻去除暴露表面的薄层沉积物。

为获取硅藻分析样品，研究人员使用牙签插入岩芯段，从岩芯中部挖取少量沉积物。初始采样间距为每5毫米采集一个样品，但沿岩芯向下采样频率逐渐降低。放射性碳定年样品需采集至少1 cm³的岩芯中部沉积物，采样深度分别为0-1 cm、12-13 cm、59-60 cm、77-78 cm、117-118 cm及229-230 cm。

硅藻数据以原始计数、底栖硅藻丰度、底栖-浮游硅藻比值以及底栖硅藻指数的形式呈现。所有样品均给出了计算年龄（单位：年）。沉积物岩芯的岩性录井以PowerPoint演示文稿形式提供。

本研究作为ASAC项目1130（ASAC_1130）与项目2201（ASAC_2201）的一部分完成。

项目1130公开摘要：
多数浅海环境的海底均生长有藻垫，其贡献的初级生产总量在诸多区域占比超过一半，是无脊椎动物与部分鱼类的关键食物来源。本研究旨在明确藻垫在南极海洋环境中的重要性，评估当地排污与垃圾填埋场污染的影响，并探究臭氧空洞导致的额外紫外线辐射对藻垫的作用。

项目2201公开摘要：
作为《南极条约环境保护议定书》的签署国，澳大利亚致力于全面保护南极环境。该议定书要求，南极地区的所有活动都需基于足够的信息进行规划与实施，以便预先评估并审慎判断其对南极环境的潜在影响。我国在南极开展的多数活动均集中于临海的无冰岩石狭窄带，诸多活动均存在对海洋生物造成环境损害的潜在风险。南极海域孕育了该区域最为复杂、生物多样性最丰富的动植物群落，但目前人们对其了解甚少，远不足以支撑对潜在环境影响作出审慎判断。

海底动植物被广泛认为是指示人类活动局部干扰的最适宜海洋生态系统组分：附着型海底生物与特定海域存在固定的空间关联，它们要么适应环境存活，要么死亡。一旦某一区域的附着生物消失，该海域的重新定殖需要耗费一定时间，因此海底群落结构不仅反映当前环境条件，还能整合记录过往的环境变化。与之相对，鱼类与浮游生物可自由移动，其捕获位点无法体现它们在该区域的长期停留情况。由于海底群落多样性极高，其中包含的物种具有迥异的生存策略，故而不同物种对胁迫的耐受程度差异显著，这会导致群落结构随干扰程度加剧出现一系列细微变化，而非“全有或全无”的响应模式。

本项目将对科考站附近的海底群落展开调查，以明确其受人类活动影响的严重程度，相关信息将用于优化作业流程优先级，以降低进一步环境破坏的风险。

本数据集包含以下字段：
物种、采样位点、底栖占比（%）、浮游占比（%）、深度（cm）、年龄（年）、放射性碳年龄、校正后年龄、底栖硅藻指数