DOI: 10.1016/j.quascirev.2018.05.023
Scopus记录号: 2-s2.0-85048478262
论文题名: Seasonal variability in the abundance and stable carbon-isotopic composition of lipid biomarkers in suspended particulate matter from a stratified equatorial lake (Lake Chala, Kenya/Tanzania): Implications for the sedimentary record
作者: van Bree L.G.J. ; Peterse F. ; van der Meer M.T.J. ; Middelburg J.J. ; Negash A.M.D. ; De Crop W. ; Cocquyt C. ; Wieringa J.J. ; Verschuren D. ; Sinninghe Damsté J.S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 192 起始页码: 208
结束页码: 224
语种: 英语
英文关键词: Aquatic biomarkers
; East Africa
; Organic geochemistry
; Paleoclimatology
; Paleolimnology
; Stable isotopes
Scopus关键词: Alkalinity
; Aquatic organisms
; Carbon
; Fatty acids
; Geochemistry
; Isotopes
; Lakes
; Mixing
; Paleolimnology
; Paraffins
; Phytoplankton
; Productivity
; Aquatic biomarkers
; East Africa
; Organic geochemistry
; Paleoclimatology
; Stable isotopes
; Biomarkers
; Bacillariophyta
; Cyanobacteria
; Eustigmatophyceae
; Tracheophyta
英文摘要: We studied the distribution and stable carbon-isotopic (δ13C) composition of various lipid biomarkers in suspended particulate matter (SPM) from the water column of Lake Chala, a permanently stratified crater lake in equatorial East Africa, to evaluate their capacity to reflect seasonality in water-column processes and associated changes in the lake's phytoplankton community. This lake has large seasonal variation in water-column dynamics (stratified during wet seasons and mixing during dry seasons) with associated phytoplankton succession. We analyzed lipid biomarkers in SPM collected monthly at 5 depths (0–80 m) from September 2013 to January 2015. Seasonal variation in total phytoplankton biovolume is strongly reflected in the concentration of phytadienes, a derivative of the general photosynthetic pigment chlorophyll. The wax and wane of several specific biomarker lipids between June and December 2014 reflect pronounced phytoplankton succession after deep mixing, starting with a long and sustained chlorophyte bloom (reflected by C23:1, C25:1 and C27:1 n-alkenes, and C21 and C23 n-alkanes), followed by a peak in diatoms between July and October (loliolide and isololiolide), and then eustigmatophytes (C30 and C32 1,15 diols) once stratification resumes in October. Peak abundance of the C19:1 n-alkene during shallow mixing of the water column in January–February 2014 can be tentatively linked to the seasonal distribution of cyanobacteria. The concentration, seasonal variability, and low δ13C values of the C28 fatty acid in the SPM suggest that this biomarker is produced in the water column of Lake Chala instead of having the typically assumed vascular plant origin. The δ13C signature of particulate carbon and all aquatic biomarkers become increasingly more negative (by up to 16‰) during mixing-induced episodes of high productivity, whereas enrichment would be expected during such blooms. This reversed fractionation may be attributed to chemically enhanced diffusion, which generates depleted HCO3 − under high pH (>9) conditions, as occur in the epilimnion of Lake Chala during periods of high productivity. The influence of this process can potentially explain previously observed 13C-depleted carbon signatures in the paleorecord of Lake Chala, and should be considered prior to paleorecord interpretation of organic-matter δ13C values derived (partially) from aquatic organisms in high-pH, i.e. alkaline, lakes. © 2018 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112149
Appears in Collections: 气候减缓与适应
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作者单位: Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Princetonlaan 8A, Utrecht, CD 3584, Netherlands; NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Utrecht University, PO Box 59, Den Burg, AB 1790, Netherlands; Ghent University, Limnology Unit, K.L. Ledeganckstraat 35, Gent, B-9000, Belgium; Meise Botanic Garden, Nieuwelaan 38, Meise, B-1860, Belgium; Naturalis Biodiversity Centre, P.O. Box 9517, Leiden, RA 2300, Netherlands
Recommended Citation:
van Bree L.G.J.,Peterse F.,van der Meer M.T.J.,et al. Seasonal variability in the abundance and stable carbon-isotopic composition of lipid biomarkers in suspended particulate matter from a stratified equatorial lake (Lake Chala, Kenya/Tanzania): Implications for the sedimentary record[J]. Quaternary Science Reviews,2018-01-01,192