Oden Southern Ocean 2008-09 - Yager - Sea Ice microbial biogeochemistry

The Oden Southern Ocean 2008-2009 expedition (OSO08), which was an international collaborative research project, took place between November 2008 and January 2009 and traveled across the poorly studied south Pacific sector of the Antarctic between Montevideo, Uruguay and McMurdo Station, Antarctica. Although sea-ice biota have been studied for decades, the Oden cruise afforded a unique opportunity to study their impact on climate-sensitive biogeochemistry. The Antarctic transect covered more than 3000 miles of the ice-covered Pacific sector, allowing us to sample a large range of sea-ice conditions and types, normally unavailable within a single expedition. Our measurements should provide insight to relationships between climate-active gas fluxes, microbial activity, and physical variables potentially measurable by satellite. We collected sea ice (cores), brine (from sackholes), and under-ice seawater from 16 stations between 70°S, 107°W and 76°S, 151°W in the Amundsen Sea and measured concentrations of inorganic and organic carbon and nitrogen, along with microbiological biomass and rate measurements. The Yager group measured concentrations of total inorganic carbon, bacterial abundance, bacterial community structure, bacterial production and respiration, as well as bacterial incorporation and respiration of model organic carbon substrates such as amino acids and methyl bromide.

奥登南大洋2008-2009科考航次（Oden Southern Ocean 2008-2009 expedition，OSO08）是一项国际合作研究项目，于2008年11月至2009年1月间实施，航行穿越南极地区研究程度极低的南太平洋扇区，航线覆盖乌拉圭蒙得维的亚（Montevideo）至南极洲麦克默多站（McMurdo Station）。尽管海冰生物群（sea-ice biota）的相关研究已开展数十年，但本次奥登航次为探究其对气候敏感型生物地球化学过程的影响提供了独特契机。本次南极科考样带覆盖冰覆盖的太平洋扇区逾3000英里海域，使我们得以采集单次航次通常难以获取的多样海冰环境与类型样本。本研究的观测数据将有助于揭示气候活性气体通量、微生物活动与卫星可潜在观测的物理变量之间的关联。我们在阿蒙森海（Amundsen Sea）内70°S, 107°W至76°S, 151°W之间的16个科考站位，采集了海冰岩芯（sea ice cores）、囊孔卤水以及冰下海水样本，并测定了无机碳、有机碳与氮的浓度，同时开展了微生物生物量及相关速率测定。耶格尔课题组（Yager group）则测定了总无机碳浓度、细菌丰度、细菌群落结构、细菌生产与呼吸速率，以及细菌对氨基酸、溴甲烷（methyl bromide）等典型有机碳底物的同化与呼吸作用。