Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2018GL078571 |
Drivers of Oxygen Consumption in the Northern Gulf of Mexico Hypoxic Waters-A Stable Carbon Isotope Perspective | |
Wang, Hongjie1; Hu, Xinping1; Rabalais, Nancy N.2,3; Brandes, Jay4 | |
2018-10-16 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS |
ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2018 |
卷号 | 45期号:19页码:10528-10538 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | We examined the stable carbon isotopic composition of remineralized organic carbon (delta C-13(OCx)) in the northern Gulf of Mexico (nGoM) using incubations (sediment and water) and a three-end-member mixing model. delta C-13(OCx) in incubating sediments was -18.1 parts per thousand +/- 1.3 parts per thousand, and delta C-13(OCx) in incubating near-surface and near-bottom waters varied with salinity, ranging from -30.4 parts per thousand to -16.2 parts per thousand from brackish water to full-strength Gulf water. The average delta C-13(OCx) was -18.6 parts per thousand +/- 1.8 parts per thousand at salinity >23. A three-end-member mixing model based on a multiyear data set collected in previous summer hypoxia cruises (2011, 2012, 2014, 2015, and 2016) suggested that delta C-13(OCx) in near-bottom waters across the nGoM (5-50 m) was -18.1 parts per thousand +/- 0.6 parts per thousand. The close agreement of delta C-13(OCx) obtained from the three independent approaches, that is, incubations of water column, surface sediments, and mixing model, suggests that C-13-enriched organic matter of marine origin played the dominant role in near- bottom water and benthic oxygen consumption in the nGoM shelf in summer. Plain Language Summary Bottom water hypoxia, that is, dissolved oxygen concentration < 2 mg/L, has been increasingly disrupting important coastal ecosystems. The ultimate reasons for causing the low oxygen levels include stratified physical conditions that isolate bottom water from oxygen-rich surface water and rapid respiration in the bottom water, where microbes feed on organic matter (OM) and at the same time consume oxygen. In complex coastal environments, OM can be supplied from multiple sources, including river delivery, coastal erosion, and primary production enhanced by terrestrial nutrient loading. On the Louisiana shelf of the northern Gulf of Mexico, where extensive summer hypoxia has been frequently observed, the type of OM that fuels bottom water oxygen consumption on a broad scale has not been systematically examined. Using field data and lab experiments, we address the question regarding the OM source issue on the Louisiana shelf. Our findings suggest that respiration of terrestrial OM is restricted to a low- salinity zone where river influence is significant, while marine-generated OM is dominant in the much broader Louisiana shelf. As the marine production is closely associated with land-derived nutrients, curbing the hypoxia problem requires unambiguous and persistent management in fertilizer usage upstream. |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000448656800057 |
WOS关键词 | DISSOLVED INORGANIC CARBON ; PARTICULATE ORGANIC-CARBON ; LOWER MISSISSIPPI RIVER ; COASTAL SEDIMENTS ; SURFACE SEDIMENTS ; PORE WATERS ; OCEAN ; EUTROPHICATION ; MATTER ; NITROGEN |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/25745 |
专题 | 气候变化 |
作者单位 | 1.Texas A&M Univ, Dept Phys & Environm Sci, Corpus Christi, TX 78412 USA; 2.Louisiana State Univ, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 USA; 3.Louisiana Univ Marine Consortium, Chauvin, LA 70344 USA; 4.Univ Georgia, Skidaway Inst Oceanog, Skidaway, GA USA |
推荐引用方式 GB/T 7714 | Wang, Hongjie,Hu, Xinping,Rabalais, Nancy N.,et al. Drivers of Oxygen Consumption in the Northern Gulf of Mexico Hypoxic Waters-A Stable Carbon Isotope Perspective[J]. GEOPHYSICAL RESEARCH LETTERS,2018,45(19):10528-10538. |
APA | Wang, Hongjie,Hu, Xinping,Rabalais, Nancy N.,&Brandes, Jay.(2018).Drivers of Oxygen Consumption in the Northern Gulf of Mexico Hypoxic Waters-A Stable Carbon Isotope Perspective.GEOPHYSICAL RESEARCH LETTERS,45(19),10528-10538. |
MLA | Wang, Hongjie,et al."Drivers of Oxygen Consumption in the Northern Gulf of Mexico Hypoxic Waters-A Stable Carbon Isotope Perspective".GEOPHYSICAL RESEARCH LETTERS 45.19(2018):10528-10538. |
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