Collaborative Research: US GEOTRACES Pacific Section: Measurement of the organic complexation of dissolved iron, copper and cobalt, and total dissolved cobalt

溶解铁(Fe)、铜(Cu)和钴(Co)是浮游植物生长所必需的元素，而浮游植物生长反过来又影响海洋碳循环；然而，尽管有这一重要作用，这些生物活性元素的循环、分布和生物有效性仍然知之甚少。例如，强有机配体会影响生物利用度和溶解度，但在可变条件下，相互作用如何在整个水柱中发生变化尚不清楚。认识到需要这些数据，来自百慕大海洋科学研究所、伍兹霍尔海洋研究所和斯克里普斯海洋研究所的研究人员将在2013年GEOTRACES邮轮期间测量溶解的铁、铜和钴的有机络合以及总的溶解钴浓度。这项研究将产生一个关于这些生物活性元素在整个水柱中形态分布的重要数据集，这将有助于评估溶解的Fe、Cu和Co分布与配体浓度梯度之间的关系，并可能揭示这一动态海洋区的巨大化学梯度。关于溶解的钴浓度，这些测量应提供有关该元素的海洋生物地球化学的新见解，特别是与氧气最小地带和热液羽流有关的新见解。就更广泛的影响而言，就外展工作而言，研究人员计划通过网络、在百慕大海洋科学研究所(BIOS)参观期间、在一年一度的百慕大海洋科学服务日开放日以及与缅因州大学海洋科学教育示范中心合作举办的由五部分组成的网络研讨会系列和课堂课程，向公众传播他们的工作成果。作为该项目的一部分，伍兹霍尔海洋研究所的一名研究生和斯克里普斯海洋研究所的一名研究生将接受培训和支助。

Dissolved iron (Fe), copper (Cu), and cobalt (Co) are essential elements for phytoplankton growth which in turn influences the marine carbon cycle; however, despite this important role, the cycling, distribution, and bioavailability of these bioactive elements remains poorly understood. For example, strong organic ligands influence bioavailability and solubility, but it is unclear how interactions change throughout the water column under variable conditions. Recognizing a need for this data, researchers from the Bermuda Institute of Ocean Sciences, Woods Hole Oceanographic Institution, and Scripps Institute of Oceanography will measure the organic complexation of dissolved Fe, Cu, and Co as well as total dissolved Co concentrations during the 2013 GEOTRACES cruise which will transect the coastal upwelling zone off Peru, an intense oxygen minimum zone, the East Pacific Rise hydrothermal plume, and the oligotrophic waters near Tahiti. This study will result in a significant dataset on the speciation of these bioactive elements throughout the water column which will help assess the relationships between dissolved Fe, Cu, and Co distributions and ligand concentration gradients and will likely reveal large chemical gradients over this dynamic oceanographic region. As regards dissolved Co concentrations, these measurements should provide new insights on the marine biogeochemistry of the element, especially in relation to oxygen minimum zones and hydrothermal plumes. In terms of the broader impacts, for the outreach efforts, the researchers plan to disseminate results from their work to the public via the web, during tours at the Bermuda Institute of Ocean Sciences (BIOS), and at the annual BIOS Marine Science Service Day open house, as well as through a five-part webinar series produced in collaboration with the Center for Ocean Sciences Education Excellence-Ocean Systems at the University of Maine and classroom curricula. One graduate student from Woods Hole Oceanographic Institution and one graduate student from Scripps Institute of Oceanography would be trained and supported as part of this project.