Entry of Sewage-Derived Organic Matter from McMurdo Station, Antarctica, Into the Benthic Food Web and its Biological Consequences

美国南极计划麦克默多站的人口在南方夏季大约有一千人。未经处理的污水经浸湿器处理后，直接排放到站外20米深度的海洋环境中。虽然首席研究人员之前已经绘制了水柱中污水排放羽流的边界，但人为有机富集源被吸收并通过南极底栖生物食物网的程度尚不清楚。巧合的是，了解南极底栖生物群落的结构、组成和功能的基础主要来自在麦克默多污水排放柱边界内进行的实地研究。本研究的目的是确定污水来源的有机物质是否被底栖生物食物网吸收及其影响程度，是否存在对人为有机富集的生物反应，以及如何将其与海豹的自然有机富集进行比较。该研究将有助于认识封印对天然有机质富集的相对贡献。第二个目的是了解不同有机来源对底栖生物的相对贡献，以及这些物质在食物网中的移动方式。主要研究人员将使用稳定的碳、硫和氮同位素比率以及粪便来源的细菌作为指标，并将污水和海豹来源的有机物与来自冰下、底栖动物和水柱的天然有机来源的影响进行比较。他们将测试污水的影响比之前认为的更大的假设。这种理解对于有效的站内污水管理和政策决定，以及在人类居住地或其他有机富集源附近进行的极地底栖生物研究的设计和解释至关重要。

Abstract The population of the United States Antarctic Program at McMurdo Station is approximately one thousand people in the austral summer. Untreated sewage is disposed through a macerator and released into the marine environment as effluent directly offshore of the station at the twenty meter depth contour. Although the Principal Investigators have previously mapped the boundaries of the sewage effluent plume in the water column, the degree to which anthropogenic sources of organic enrichment is taken up and passed through the antarctic benthic food web is unknown. Coincidentally, the foundation for understanding of the structure, composition and functioning of antarctic benthic communities comes primarily from field research conducted within the boundaries of the McMurdo sewage outfall plume. The purpose of this research is to determine if sewage-derived organic material is assimilated by the benthic food web and its extent of influence and if there is a biological response to anthropogenic organic enrichment and how this compares to natural organic enrichment by seals. This research will provide an understanding of the relative contribution to natural organic enrichment by seals. A secondary purpose will be to understand the relative contribution of different organic sources to the benthos and the way that this material moves through the food web. The Principal Investigators will use stable carbon, sulfur, and nitrogen isotope ratios and fecal-derived bacteria as indices and compare the influence of sewage and seal-derived organic matter with natural organic sources from the under-ice, benthos, and water column. They will test the hypothesis that sewage influence is greater than previously thought. This understanding is essential for effective station sewage management and policy decisions and for the design and interpretation of polar benthic research conducted in the vicinity of human inhabitation or other sources of organic enrichment.