RAPID: Effect of Oil Spill on Organic Carbon Partitioning and Transformation in the Water Column in the Northern Gulf

在这笔快速反应研究补助金(RAPID)的资助下，南密西西比大学的研究人员将研究墨西哥湾北部的深水地平线漏油事件--一种具有国家意义的漏油事件--以研究从基线到最大影响的完整时间序列中原油组分的命运、运输和转化及其与海洋有机物的相互作用。他们的工作假设是，原油组分的碳-13同位素很轻，光学性质(UV-Vis和荧光发射-激发矩阵[EEM])与天然海洋有机质不同，因此可以使用稳定的同位素和荧光技术来定量了解它们在墨西哥湾北部的命运、运输和转化。他们将在墨西哥湾北部密西西比湾的一个站点收集海水样本，从基线条件到最大影响。将使用EEM荧光、稳定同位素和流场-流动分馏技术。测量将包括溶解无机碳(DIC)、溶解有机碳(DOC)和颗粒有机碳(POC)及其稳定碳同位素组成(C-13)，光学性质，包括UV-Vis吸光度、吸附系数、光谱斜率和EM、DOM的组成和粒度光谱、叶绿素-a，以及其他常见的环境参数，如盐度、温度、溶解氧和营养物质。这项研究的结果有望提供新的见解，了解漏油产生的有机物如何与海洋有机物相互作用，影响海洋碳收支、生物地球化学过程和整个海洋生态系统。这项研究将结合针对墨西哥湾北部这一史无前例的漏油事件的计划和正在进行的研究，以及更广泛的影响，有助于了解溢油的去向、运输和转化，以及它们与沿海环境中水柱中天然海洋有机物的相互作用。调查人员将与其他资助项目合作共享数据。该项目将支持一名研究生，他将在快速反应研究以及与墨西哥湾沿岸地区其他研究小组的互动方面获得宝贵经验。

With funding through this Grant for Rapid Response Research (RAPID), researchers at the University of Southern Mississippi will examine the Deepwater Horizon oil spill in the northern Gulf of Mexico -- an oil spill of national significance -- to study the fate, transport and transformation of crude oil components and their interactions with marine organic matter from baseline to maximum impact in a complete time series. Their working hypothesis is that the crude oil components are isotopically light (in terms of carbon-13) and distinct in optical properties (UV-vis and fluorescence emission-excitation matrices [EEM]) from natural marine organic matter, thus allowing the use of stable isotopes and fluorescence techniques for quantitative understanding of their fate, transport, and transformations in the northern Gulf of Mexico. They will collect seawater samples at a station in the Mississippi Bight in the northern Gulf of Mexico from base line conditions to maximum impact. EEM fluorescence, stable isotopes, and flow field-flow fractionation techniques will be employed. Measurements will include dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and particulate organic carbon (POC) and their stable carbon isotopic composition (C-13), optical properties, including UV-vis absorbance, adsorption coefficient, spectral slope, and EEMs, composition and size spectrum of DOM, chlorophyll-a, and other common environmental parameters, such as salinity, temperature, dissolved oxygen, and nutrients. Results of this study are expected to provide new insights into how organic matter from oil spills interacts with marine organic matter affecting the ocean carbon budget, biogeochemical processes, and marine ecosystems as a whole. Broader Impacts Combined with planned and ongoing research in response to this unprecedented oil spill in the northern Gulf of Mexico, this research will contribute to the understanding of the fate, transport and transformation of spilled oils and their interactions with natural marine organic matter in the water column in the coastal environment. The investigators will collaborate with other funded projects for data sharing. The project will support one graduate student, who will gain valuable experience in rapid response research as well as in interacting with other research teams in the Gulf Coast region.