Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2019GL082075 |
Recent Increases in Water Column Denitrification in the Seasonally Suboxic Bottom Waters of the Santa Barbara Basin | |
White, Margot E.1; Rafter, Patrick A.2; Stephens, Brandon M.3,4; Wankel, Scott D.5; Aluwihare, Lihini I.1 | |
2019-06-28 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS
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ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2019 |
卷号 | 46期号:12页码:6786-6795 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | Denitrification in the anoxic sediments of the Santa Barbara Basin has been well documented in the historic and modern record, but the regulation of and frequency with which denitrification occurs in the overlying water column are less understood. Since 2004, the magnitude and speciation of redox active nitrogen species in bottom waters have changed markedly. Most notable are periods of decreased nitrate and increased nitrite concentrations. Here we examine these changes in nitrogen cycling as recorded by the stable isotopes of dissolved nitrate from 2010-2016. When compared to previous studies, our data identify an increase in water column denitrification in the bottom waters of the basin. Observations from inside the basin as well as data from the wider California Current Ecosystem implicate a long-term trend of decreasing oxygen concentrations as the driver for these observed changes, with ramifications for local benthic communities and regional nitrogen loss. Plain Language Summary The current chemical environment of the deep Santa Barbara Basin is unprecedented in the 30 years since measurements began, suggesting that a regional change in ocean chemistry has occurred over this time period. Here we use stable isotope measurements of nitrate to examine how the nitrogen cycle in the deep part of the basin has changed, documenting a recent increase in the amount of nitrate being removed from the water column at this location. Nitrogen removal in the dark ocean, known as denitrification, occurs when microbes utilize nitrate for respiration in the absence of oxygen. Such a process is consistent with the extremely low or absent oxygen concentrations that accompany the altered nitrate isotope signatures we measured in this study. Denitrification in sediments is common in the Santa Barbara Basin, but extensive water column denitrification has not been previously documented. Loss of nitrate from the water column can have important consequences for the balance of nutrients that support primary production in the ocean. These changes appear to be an effect of decreasing oxygen concentrations observed on a regional scale in the North Pacific Ocean, a trend which is likely to continue as the oceans warm. |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000477616300069 |
WOS关键词 | TROPICAL SOUTH-PACIFIC ; OXYGEN-ISOTOPE FRACTIONATION ; ARABIAN SEA ; FRESH-WATER ; NITROGEN ; NITRATE ; NITRITE ; NITRIFICATION ; SEAWATER ; PERU |
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/184268 |
专题 | 气候变化 |
作者单位 | 1.Univ Calif San Diego, Scripps Inst Oceanog, San Diego, CA 92103 USA; 2.Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA USA; 3.Univ Calif Santa Barbara, Inst Marine Sci, Santa Barbara, CA 93106 USA; 4.Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA; 5.Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA |
推荐引用方式 GB/T 7714 | White, Margot E.,Rafter, Patrick A.,Stephens, Brandon M.,et al. Recent Increases in Water Column Denitrification in the Seasonally Suboxic Bottom Waters of the Santa Barbara Basin[J]. GEOPHYSICAL RESEARCH LETTERS,2019,46(12):6786-6795. |
APA | White, Margot E.,Rafter, Patrick A.,Stephens, Brandon M.,Wankel, Scott D.,&Aluwihare, Lihini I..(2019).Recent Increases in Water Column Denitrification in the Seasonally Suboxic Bottom Waters of the Santa Barbara Basin.GEOPHYSICAL RESEARCH LETTERS,46(12),6786-6795. |
MLA | White, Margot E.,et al."Recent Increases in Water Column Denitrification in the Seasonally Suboxic Bottom Waters of the Santa Barbara Basin".GEOPHYSICAL RESEARCH LETTERS 46.12(2019):6786-6795. |
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