DOI: 10.1007/s10533-017-0311-3
Scopus记录号: 2-s2.0-85014256930
论文题名: Seasonal benthic nitrogen cycling in a temperate shelf sea: the Celtic Sea
作者: Kitidis V. ; Tait K. ; Nunes J. ; Brown I. ; Woodward E.M.S. ; Harris C. ; Sabadel A.J.M. ; Sivyer D.B. ; Silburn B. ; Kröger S.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 135, 期: 2018-01-02 起始页码: 103
结束页码: 119
语种: 英语
英文关键词: Anammox
; Denitrification
; N-cycle
; Nitrification
; Sediment
; Shelf-seas
Scopus关键词: ammonium compound
; anoxic conditions
; cohesive sediment
; continental shelf
; denitrification
; inorganic nitrogen
; nitrification
; nitrogen cycle
; organic matter
; oxidation
; oxygen consumption
; phytoplankton
; porewater
; seafloor
; seasonal variation
; shelf sea
; water column
; Atlantic Ocean
; Celtic Sea
英文摘要: We undertook a seasonal study of benthic N-cycling on the Celtic Sea continental shelf in 2015, augmented by an earlier cruise in 2014. Two cruises in 2015 were centred before and after the Spring phytoplankton bloom and a further cruise was carried out in late summer. Five sites covering the mud to sand continuum were visited on all cruises, where we determined ammonium-oxidation, anammox and denitrification rates, expression of anammox and denitrification genes, N-nutrient fluxes and sediment porewater profiles of N-nutrients. Highest process rates were found during the post-bloom and late summer periods. The Celtic Sea was overwhelmingly a source of inorganic-N to the overlying water column. The efflux of nitrate was controlled by the magnitude of ammonium-oxidation. The latter accounted for 10–16% of total Oxygen consumption in cohesive sediments and 35–56% in sandy sediments. Ammonium oxidation rates in the range of 0.001–2.288 mmol m−2 days−1 were inversely correlated with sediment porosity and positively correlated with organic matter content (OM) which together explained 66% of the variance in rates. N-removal was dominated by anammox (0.003–0.636 mmol m−2 days−1), rather than denitrification (0.000–0.034 mmol m−2 days−1). This finding was supported by the corresponding gene expression data. The expression of hydrazine oxidoreductase (anammox) was significantly correlated with anammox and total N-removal rates. Anammox was positively correlated with porosity and OM, whilst denitrification was correlated with OM. The N-requirement of these processes was largely met through nitrification (ammonium-oxidation) rather than influx from the overlying water column. We estimated that N-removal via denitrification and anammox removed 6–9% of the organic-N deposited at the sea-floor from the overlying water column. The Celtic Sea system was thereby losing N which must be replenished on an annual basis in order to sustain productivity. © 2017, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83233
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Plymouth Marine Laboratory, Plymouth, United Kingdom; Department of Chemistry, University of Otago, Dunedin, New Zealand; Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Lowestoft, United Kingdom
Recommended Citation:
Kitidis V.,Tait K.,Nunes J.,et al. Seasonal benthic nitrogen cycling in a temperate shelf sea: the Celtic Sea[J]. Biogeochemistry,2017-01-01,135(2018-01-02)