DOI: 10.1007/s10533-017-0323-z
Scopus记录号: 2-s2.0-85016484204
论文题名: Benthic pH gradients across a range of shelf sea sediment types linked to sediment characteristics and seasonal variability
作者: Silburn B. ; Kröger S. ; Parker E.R. ; Sivyer D.B. ; Hicks N. ; Powell C.F. ; Johnson M. ; Greenwood N.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 135, 期: 2018-01-02 起始页码: 69
结束页码: 88
语种: 英语
英文关键词: Carbon cycle
; Celtic sea
; Microelectrode profiles
; Oxygen
; Sediment pH
; Shelf sea biogeochemistry
Scopus关键词: benthic environment
; biogeochemistry
; carbon cycle
; electrode
; oxygen
; pH
; seasonal variation
; sediment chemistry
; shelf sea
; shelf sediment
; Atlantic Ocean
; Celtic Sea
英文摘要: This study used microelectrodes to record pH profiles in fresh shelf sea sediment cores collected across a range of different sediment types within the Celtic Sea. Spatial and temporal variability was captured during repeated measurements in 2014 and 2015. Concurrently recorded oxygen microelectrode profiles and other sedimentary parameters provide a detailed context for interpretation of the pH data. Clear differences in profiles were observed between sediment type, location and season. Notably, very steep pH gradients exist within the surface sediments (10–20 mm), where decreases greater than 0.5 pH units were observed. Steep gradients were particularly apparent in fine cohesive sediments, less so in permeable sandier matrices. We hypothesise that the gradients are likely caused by aerobic organic matter respiration close to the sediment–water interface or oxidation of reduced species at the base of the oxic zone (NH4 +, Mn2+, Fe2+, S−). Statistical analysis suggests the variability in the depth of the pH minima is controlled spatially by the oxygen penetration depth, and seasonally by the input and remineralisation of deposited organic phytodetritus. Below the pH minima the observed pH remained consistently low to maximum electrode penetration (ca. 60 mm), indicating an absence of sub-oxic processes generating H+ or balanced removal processes within this layer. Thus, a climatology of sediment surface porewater pH is provided against which to examine biogeochemical processes. This enhances our understanding of benthic pH processes, particularly in the context of human impacts, seabed integrity, and future climate changes, providing vital information for modelling benthic response under future climate scenarios. © 2017, The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83229
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: Centre for Environment Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, Suffolk, United Kingdom; Scottish Marine Institute, Oban, Argyll, United Kingdom; University of East Anglia, Norwich Research Park, Norwich, Norfolk, United Kingdom
Recommended Citation:
Silburn B.,Kröger S.,Parker E.R.,et al. Benthic pH gradients across a range of shelf sea sediment types linked to sediment characteristics and seasonal variability[J]. Biogeochemistry,2017-01-01,135(2018-01-02)