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Tian H, Du Y, Deng Y, Sun X, Xu J, Gan Y, Wang Y. Identification of methane cycling pathways in Quaternary alluvial-lacustrine aquifers using multiple isotope and microbial indicators. WATER RESEARCH 2024; 250:121027. [PMID: 38113595 DOI: 10.1016/j.watres.2023.121027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/07/2023] [Accepted: 12/15/2023] [Indexed: 12/21/2023]
Abstract
Groundwater rich in dissolved methane is often overlooked in the global or regional carbon cycle. Considering the knowledge gap in understanding the biogeochemical behavior of methane in shallow aquifers, particularly those in humid alluvial-lacustrine plains with high organic carbon content, we investigated methane sources and cycling pathways in groundwater systems at the central Yangtze River basins. Composition of multiple stable isotopes (2H/18O in water, 13C in dissolved inorganic carbon, 13C/2H in methane, and 13C in carbon dioxide) was combined with the characteristics of microbes and dissolved organic matter (DOM) in the study. The results revealed significant concentrations of biogenic methane reaching up to 13.05 mg/L in anaerobic groundwater environments with abundant organic matter. Different pathways for methane cycling (methanogenic CO2-reduction and acetate-fermentation, and methane oxidation) were identified. CO2-reduction dominated acetate-fermentation in the two methanogenic pathways primarily associated with humic DOM, while methane oxidation was more closely associated with microbially derived DOM. The abundance of obligate CO2-reduction microorganisms (Methanobacterium and Methanoregula) was higher in samples with substantial CO2-reduction, as indicated by isotopic composition. The obligate acetate-fermentation microorganism (Methanosaeta) was more abundant in samples exhibiting evident acetate-fermentation. Additionally, a high abundance of Candidatus Methanoperedens was identified in samples with apparent methane oxidation. Comparing our findings with those in other areas, we found that various factors, such as groundwater temperature, DOM abundance and types, and hydrogeological conditions, may lead to differences in groundwater methane cycling. This study offered a new perspective and understanding of methane cycling in worldwide shallow alluvial-lacustrine aquifer systems without geothermal disturbance.
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Affiliation(s)
- Hao Tian
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China
| | - Yao Du
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China.
| | - Yamin Deng
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China
| | - Xiaoliang Sun
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China
| | - Jiawen Xu
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China
| | - Yiqun Gan
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China
| | - Yanxin Wang
- MOE Key Laboratory of Groundwater Quality and Health, China University of Geosciences, Wuhan 430078, China; School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430078, China
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Groundwater discharge as a driver of methane emissions from Arctic lakes. Nat Commun 2022; 13:3667. [PMID: 35760781 PMCID: PMC9237097 DOI: 10.1038/s41467-022-31219-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 06/06/2022] [Indexed: 11/18/2022] Open
Abstract
Lateral CH4 inputs to Arctic lakes through groundwater discharge could be substantial and constitute an important pathway that links CH4 production in thawing permafrost to atmospheric emissions via lakes. Yet, groundwater CH4 inputs and associated drivers are hitherto poorly constrained because their dynamics and spatial variability are largely unknown. Here, we unravel the important role and drivers of groundwater discharge for CH4 emissions from Arctic lakes. Spatial patterns across lakes suggest groundwater inflows are primarily related to lake depth and wetland cover. Groundwater CH4 inputs to lakes are higher in summer than in autumn and are influenced by hydrological (groundwater recharge) and biological drivers (CH4 production). This information on the spatial and temporal patterns on groundwater discharge at high northern latitudes is critical for predicting lake CH4 emissions in the warming Arctic, as rising temperatures, increasing precipitation, and permafrost thawing may further exacerbate groundwater CH4 inputs to lakes. CH4 inputs to Arctic lakes via groundwater discharge are an important pathway that links CH4 production in thawing permafrost to emission via lakes. Here the authors unravel the role and drivers of groundwater inflows for CH4 emissions from Arctic lakes.
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Hudson JM, Michaud AB, Emerson D, Chin YP. Spatial distribution and biogeochemistry of redox active species in arctic sedimentary porewaters and seeps. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:426-438. [PMID: 35170586 DOI: 10.1039/d1em00505g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Redox active species in Arctic lacustrine sediments play an important, regulatory role in the carbon cycle, yet there is little information on their spatial distribution, abundance, and oxidation states. Here, we use voltammetric microelectrodes to quantify the in situ concentrations of redox-active species at high vertical resolution (mm to cm) in the benthic porewaters of an oligotrophic Arctic lake (Toolik Lake, AK, USA). Mn(II), Fe(II), O2, and Fe(III)-organic complexes were detected as the major redox-active species in these porewaters, indicating both Fe(II) oxidation and reductive dissolution of Fe(III) and Mn(IV) minerals. We observed significant spatial heterogeneity in their abundance and distribution as a function of both location within the lake and depth. Microbiological analyses and solid phase Fe(III) measurements were performed in one of the Toolik Lake cores to determine the relationship between biogeochemical redox gradients and microbial communities. Our data reveal iron cycling involving both oxidizing (FeOB) and reducing (FeRB) bacteria. Additionally, we profiled a large microbial iron mat in a tundra seep adjacent to an Arctic stream (Oksrukuyik Creek) where we observed Fe(II) and soluble Fe(III) in a highly reducing environment. The variable distribution of redox-active substances at all the sites yields insights into the nature and distribution of the important terminal electron acceptors in both lacustrine and tundra environments capable of exerting significant influences on the carbon cycle.
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Affiliation(s)
- Jeffrey M Hudson
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware 19716, USA.
| | | | - David Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Yu-Ping Chin
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware 19716, USA.
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4
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Recent Changes in Groundwater and Surface Water in Large Pan-Arctic River Basins. REMOTE SENSING 2022. [DOI: 10.3390/rs14030607] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Surface and groundwater in large pan-Arctic river basins are changing rapidly. High-quality estimates of these changes are challenging because of the limits on the data quality and time span of satellite observations. Here, the term pan-Arctic river refers to the rivers flowing to the Arctic Ocean basin. In this study, we provide a new evaluation of groundwater storage (GWS) changes in the Lena, Ob, Yenisei, Mackenzie and Yukon River basins from the GRACE total water storage anomaly product, in situ runoff, soil moisture form models and a snow water equivalent product that has been significantly improved. Seasonal Trend decomposition using Loess was utilized to obtain trends in GWS. Changes in surface water (SW) between 1984 and 2019 in these basins were also examined based on the Joint Research Centre Global Surface Water Transition data. Results suggested that there were great GWS losses in the North American river basins, totaling approximately −219 km3, and GWS gains in the Siberian river basins, totaling ~340 km3, during 2002–2017. New seasonal and permanent SWs are the primary contributors to the SW transition, accounting for more than 50% of the area of the changed SW in each basin. Changes in the Arctic hydrological system will be more significant and various in the case of rapid and continuous changes in permafrost.
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5
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Eugster W, DelSontro T, Shaver GR, Kling GW. Interannual, summer, and diel variability of CH 4 and CO 2 effluxes from Toolik Lake, Alaska, during the ice-free periods 2010-2015. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:2181-2198. [PMID: 33078814 DOI: 10.1039/d0em00125b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Accelerated warming in the Arctic has led to concern regarding the amount of carbon emission potential from Arctic water bodies. Yet, aquatic carbon dioxide (CO2) and methane (CH4) flux measurements remain scarce, particularly at high resolution and over long periods of time. Effluxes of methane (CH4) and carbon dioxide (CO2) from Toolik Lake, a deep glacial lake in northern Alaska, were measured for the first time with the direct eddy covariance (EC) flux technique during six ice-free lake periods (2010-2015). CO2 flux estimates from the lake (daily average efflux of 16.7 ± 5.3 mmol m-2 d-1) were in good agreement with earlier estimates from 1975-1989 using different methods. CH4 effluxes in 2010-2015 (averaging 0.13 ± 0.06 mmol m-2 d-1) showed an interannual variation that was 4.1 times greater than median diel variations, but mean fluxes were almost one order of magnitude lower than earlier estimates obtained from single water samples in 1990 and 2011-2012. The overall global warming potential (GWP) of Toolik Lake is thus governed mostly by CO2 effluxes, contributing 86-93% of the ice-free period GWP of 26-90 g CO2,eq m-2. Diel variation in fluxes was also important, with up to a 2-fold (CH4) to 4-fold (CO2) difference between the highest nighttime and lowest daytime effluxes. Within the summer ice-free period, on average, CH4 fluxes increased 2-fold during the first half of the summer, then remained almost constant, whereas CO2 effluxes remained almost constant over the entire summer, ending with a linear increase during the last 1-2 weeks of measurements. Due to the cold bottom temperatures of this 26 m deep lake, and the absence of ebullition and episodic flux events, Toolik Lake and other deep glacial lakes are likely not hot spots for greenhouse gas emissions, but they still contribute to the overall GWP of the Arctic.
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Affiliation(s)
- Werner Eugster
- Institute of Agricultural Sciences, Department of Environmental Systems Science, ETH Zürich, CH-8092 Zürich, Switzerland.
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6
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Thalasso F, Sepulveda-Jauregui A, Gandois L, Martinez-Cruz K, Gerardo-Nieto O, Astorga-España MS, Teisserenc R, Lavergne C, Tananaev N, Barret M, Cabrol L. Sub-oxycline methane oxidation can fully uptake CH 4 produced in sediments: case study of a lake in Siberia. Sci Rep 2020; 10:3423. [PMID: 32099029 PMCID: PMC7042212 DOI: 10.1038/s41598-020-60394-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 02/10/2020] [Indexed: 11/09/2022] Open
Abstract
It is commonly assumed that methane (CH4) released by lakes into the atmosphere is mainly produced in anoxic sediment and transported by diffusion or ebullition through the water column to the surface of the lake. In contrast to that prevailing idea, it has been gradually established that the epilimnetic CH4 does not originate exclusively from sediments but is also locally produced or laterally transported from the littoral zone. Therefore, CH4 cycling in the epilimnion and the hypolimnion might not be as closely linked as previously thought. We utilized a high-resolution method used to determine dissolved CH4 concentration to analyze a Siberian lake in which epilimnetic and hypolimnetic CH4 cycles were fully segregated by a section of the water column where CH4 was not detected. This layer, with no detected CH4, was well below the oxycline and the photic zone and thus assumed to be anaerobic. However, on the basis of a diffusion-reaction model, molecular biology, and stable isotope analyses, we determined that this layer takes up all the CH4 produced in the sediments and the deepest section of the hypolimnion. We concluded that there was no CH4 exchange between the hypolimnion (dominated by methanotrophy and methanogenesis) and the epilimnion (dominated by methane lateral transport and/or oxic production), resulting in a vertically segregated lake internal CH4 cycle.
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Affiliation(s)
- Frédéric Thalasso
- Biotechnology and Bioengineering Department, Center for Research and Advanced Studies (Cinvestav), Mexico City, Mexico.,The Environmental Biogeochemistry in Extreme Ecosystems Laboratory (EnBEELab), University of Magallanes, Punta Arenas, Chile
| | - Armando Sepulveda-Jauregui
- The Environmental Biogeochemistry in Extreme Ecosystems Laboratory (EnBEELab), University of Magallanes, Punta Arenas, Chile. .,Center for Climate and Resilience Research (CR)2, Santiago, Chile.
| | - Laure Gandois
- EcoLab, Université de Toulouse, CNRS, Toulouse, France
| | - Karla Martinez-Cruz
- The Environmental Biogeochemistry in Extreme Ecosystems Laboratory (EnBEELab), University of Magallanes, Punta Arenas, Chile
| | - Oscar Gerardo-Nieto
- Biotechnology and Bioengineering Department, Center for Research and Advanced Studies (Cinvestav), Mexico City, Mexico
| | - María S Astorga-España
- The Environmental Biogeochemistry in Extreme Ecosystems Laboratory (EnBEELab), University of Magallanes, Punta Arenas, Chile
| | | | - Céline Lavergne
- Escuela de Ingeniería Bioquímica, Pontificia Universidad de Valparaiso, Valparaiso, Chile
| | | | | | - Léa Cabrol
- Aix-Marseille University, Univ Toulon, CNRS, IRD, Mediterranean Institute of Oceanography, Marseille, France
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7
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Kendrick MR, Huryn AD, Bowden WB, Deegan LA, Findlay RH, Hershey AE, Peterson BJ, Beneš JP, Schuett EB. Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river. GLOBAL CHANGE BIOLOGY 2018; 24:5738-5750. [PMID: 30218544 DOI: 10.1111/gcb.14448] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 08/04/2018] [Accepted: 08/18/2018] [Indexed: 05/21/2023]
Abstract
Rapidly, increasing air temperatures across the Arctic are thawing permafrost and exposing vast quantities of organic carbon, nitrogen, and phosphorus to microbial processing. Shifts in the absolute and relative supplies of these elements will likely alter patterns of ecosystem productivity and change the way carbon and nutrients are delivered from upland areas to surface waters such as rivers and lakes. The ultra-oligotrophic nature of surface waters across the Arctic renders these ecosystems particularly susceptible to changes in productivity and food web dynamics as permafrost thaw alters terrestrial-aquatic linkages. The objectives of this study were to evaluate decadal-scale patterns in surface water chemistry and assess potential implications of changing water chemistry to benthic organic matter and aquatic food webs. Data were collected from the upper Kuparuk River on the North Slope of Alaska by the U.S. National Science Foundation's Long-Term Ecological Research program during 1978-2014. Analyses of these data show increases in stream water alkalinity and cation concentrations consistent with signatures of permafrost thaw. Changes are also documented for discharge-corrected nitrate concentrations (+), discharge-corrected dissolved organic carbon concentrations (-), total phosphorus concentrations (-), and δ13 C isotope values of aquatic invertebrate consumers (-). These changes show that warming temperatures and thawing permafrost in the upland environment are leading to shifts in the supply of carbon and nutrients available to surface waters and consequently changing resources that support aquatic food webs. This demonstrates that physical, geochemical, and biological changes associated with warming permafrost are fundamentally altering linkages between upland and aquatic ecosystems in rapidly changing arctic environments.
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Affiliation(s)
- Michael R Kendrick
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama
| | - Alexander D Huryn
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama
| | - William B Bowden
- Rubenstein School of Environment & Natural Resources, University of Vermont, Burlington, Vermont
| | | | - Robert H Findlay
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama
| | - Anne E Hershey
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Bruce J Peterson
- Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - Joshua P Beneš
- Rubenstein School of Environment & Natural Resources, University of Vermont, Burlington, Vermont
| | - Elissa B Schuett
- Rubenstein School of Environment & Natural Resources, University of Vermont, Burlington, Vermont
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8
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Abstract
Submarine groundwater discharge (SGD) is a global and well-studied geological process by which groundwater of varying salinities enters coastal waters. SGD is known to transport bioactive solutes, including but not limited to nutrients (nitrogen, phosphorous, silica), gases (methane, carbon dioxide), and trace metals (iron, nickel, zinc). In addition, physical changes to the water column, such as changes in temperature and mixing can be caused by SGD. Therefore SGD influences both autotrophic and heterotrophic marine biota across all kingdoms of life. This paper synthesizes the current literature in which the impacts of SGD on marine biota were measured and observed by field, modeling, or laboratory studies. The review is grouped by organismal complexity: bacteria and phytoplankton, macrophytes (macroalgae and marine plants), animals, and ecosystem studies. Directions for future research about the impacts of SGD on marine life, including increasing the number of ecosystem assessment studies and including biological parameters in SGD flux studies, are also discussed.
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9
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Climate and permafrost effects on the chemistry and ecosystems of High Arctic Lakes. Sci Rep 2017; 7:13292. [PMID: 29038475 PMCID: PMC5643399 DOI: 10.1038/s41598-017-13658-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 09/25/2017] [Indexed: 11/25/2022] Open
Abstract
Permafrost exerts an important control over hydrological processes in Arctic landscapes and lakes. Recent warming and summer precipitation has the potential to alter water availability and quality in this environment through thermal perturbation of near surface permafrost and increased mobility of previously frozen solutes to Arctic freshwaters. We present a unique thirteen-year record (2003–16) of the physiochemical properties of two High Arctic lakes and show that the concentration of major ions, especially SO42−, has rapidly increased up to 500% since 2008. This hydrochemical change has occurred synchronously in both lakes and ionic ratio changes in the lakes indicate that the source for the SO42− is compositionally similar to terrestrial sources arising from permafrost thaw. Record summer temperatures during this period (2003–16) following over 100 years of warming and summer precipitation in this polar desert environment provide likely mechanisms for this rapid chemical change. An abrupt limnological change is also reflected in the otolith chemistry and improved relative condition of resident Arctic char (Salvelinus alpinus) and increased diatom diversity point to a positive ecosystem response during the same period.
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10
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Groundwater Discharge in the Arctic: A Review of Studies and Implications for Biogeochemistry. HYDROLOGY 2017. [DOI: 10.3390/hydrology4030041] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Stackpoole SM, Butman DE, Clow DW, Verdin KL, Gaglioti BV, Genet H, Striegl RG. Inland waters and their role in the carbon cycle of Alaska. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:1403-1420. [PMID: 28376236 DOI: 10.1002/eap.1552] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 03/20/2017] [Accepted: 03/24/2017] [Indexed: 05/08/2023]
Abstract
The magnitude of Alaska (AK) inland waters carbon (C) fluxes is likely to change in the future due to amplified climate warming impacts on the hydrology and biogeochemical processes in high latitude regions. Although current estimates of major aquatic C fluxes represent an essential baseline against which future change can be compared, a comprehensive assessment for AK has not yet been completed. To address this gap, we combined available data sets and applied consistent methodologies to estimate river lateral C export to the coast, river and lake carbon dioxide (CO2 ) and methane (CH4 ) emissions, and C burial in lakes for the six major hydrologic regions in the state. Estimated total aquatic C flux for AK was 41 Tg C/yr. Major components of this total flux, in Tg C/yr, were 18 for river lateral export, 17 for river CO2 emissions, and 8 for lake CO2 emissions. Lake C burial offset these fluxes by 2 Tg C/yr. River and lake CH4 emissions were 0.03 and 0.10 Tg C/yr, respectively. The Southeast and South central regions had the highest temperature, precipitation, terrestrial net primary productivity (NPP), and C yields (fluxes normalized to land area) were 77 and 42 g C·m-2 ·yr-1 , respectively. Lake CO2 emissions represented over half of the total aquatic flux from the Southwest (37 g C·m-2 ·yr-1 ). The North Slope, Northwest, and Yukon regions had lesser yields (11, 15, and 17 g C·m2 ·yr-1 ), but these estimates may be the most vulnerable to future climate change, because of the heightened sensitivity of arctic and boreal ecosystems to intensified warming. Total aquatic C yield for AK was 27 g C·m-2 ·yr-1 , which represented 16% of the estimated terrestrial NPP. Freshwater ecosystems represent a significant conduit for C loss, and a more comprehensive view of land-water-atmosphere interactions is necessary to predict future climate change impacts on the Alaskan ecosystem C balance.
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Affiliation(s)
- Sarah M Stackpoole
- U.S. Geological Survey, National Research Program, Denver Federal Center, MS413, Denver, Colorado, 80225, USA
| | - David E Butman
- National Research Program, U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado, 80303, USA
- School of Environmental and Forest Sciences and Civil & Environmental Engineering, University of Washington - Seattle, Box 325100, Seattle, Washington, 98195, USA
| | - David W Clow
- U.S. Geological Survey, Colorado Water Science Center, Denver Federal Center, MS415, Denver, Colorado, 80225, USA
| | - Kristine L Verdin
- U.S. Geological Survey, Colorado Water Science Center, Denver Federal Center, MS415, Denver, Colorado, 80225, USA
| | - Benjamin V Gaglioti
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, Alaska, 99508, USA
- Tree Ring Lab, Lamont-Doherty Earth Observatory, 61 Route 9W - PO Box 1000, Palisades, New York, 10964, USA
| | - Hélène Genet
- Institute of Arctic Biology, University of Alaska - Fairbanks, 902 Koyukuk Drive, Fairbanks, Alaska, 99775, USA
| | - Robert G Striegl
- National Research Program, U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado, 80303, USA
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12
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Dean JF, Billett MF, Murray C, Garnett MH. Ancient dissolved methane in inland waters revealed by a new collection method at low field concentrations for radiocarbon ( 14C) analysis. WATER RESEARCH 2017; 115:236-244. [PMID: 28284090 DOI: 10.1016/j.watres.2017.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 02/27/2017] [Accepted: 03/04/2017] [Indexed: 06/06/2023]
Abstract
Methane (CH4) is a powerful greenhouse gas that plays a prominent role in the terrestrial carbon (C) cycle, and is released to the atmosphere from freshwater systems in numerous biomes globally. Radiocarbon (14C) analysis can indicate both the age and source of CH4 in natural environments. In contrast to CH4 present in bubbles released from aquatic sediments (ebullition), dissolved CH4 in lakes and streams can be present in low concentrations compared to carbon dioxide (CO2), and therefore obtaining sufficient aquatic CH4 for radiocarbon (14C) analysis remains a major technical challenge. Previous studies have shown that freshwater CH4, in both dissolved and ebullitive form, can be significantly older than other forms of aquatic C, and it is therefore important to characterise this part of the terrestrial C balance. This study presents a novel method to capture sufficient amounts of dissolved CH4 for 14C analysis in freshwater environments by circulating water across a hydrophobic, gas-permeable membrane and collecting the CH4 in a large headspace volume. The results of laboratory and field tests show that reliable dissolved δ13CH4 and 14CH4 samples can be readily collected over short time periods (∼4-24 h), at relatively low cost and from a variety of surface water types. The initial results further support previous findings that dissolved CH4 may be significantly older than other forms of aquatic C, and is currently unaccounted for in many terrestrial C balances and models. This method is suitable for use in remote locations, and could potentially be used to detect the leakage of unique 14CH4 signatures from point sources into waterways, e.g. coal seam gas and landfill gas.
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Affiliation(s)
- Joshua F Dean
- NERC Radiocarbon Facility, East Kilbride, G75 0QF, UK; Department of Earth Sciences, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands.
| | - Michael F Billett
- Biological and Environment Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Callum Murray
- NERC Radiocarbon Facility, East Kilbride, G75 0QF, UK
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13
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Northington RM, Saros JE. Factors Controlling Methane in Arctic Lakes of Southwest Greenland. PLoS One 2016; 11:e0159642. [PMID: 27454863 PMCID: PMC4959701 DOI: 10.1371/journal.pone.0159642] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 07/06/2016] [Indexed: 11/30/2022] Open
Abstract
We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.
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Affiliation(s)
- Robert M. Northington
- Climate Change Institute, University of Maine, Orono, ME, 04469, United States of America
- * E-mail:
| | - Jasmine E. Saros
- Climate Change Institute, University of Maine, Orono, ME, 04469, United States of America
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14
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Dimova NT, Paytan A, Kessler JD, Sparrow KJ, Garcia-Tigreros Kodovska F, Lecher AL, Murray J, Tulaczyk SM. Current Magnitude and Mechanisms of Groundwater Discharge in the Arctic: Case Study from Alaska. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12036-12043. [PMID: 26372173 DOI: 10.1021/acs.est.5b02215] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
To better understand groundwater-surface water dynamics in high latitude areas, we conducted a field study at three sites in Alaska with varying permafrost coverage. The natural groundwater tracer ((222)Rn, radon) was used to evaluate groundwater discharge, and electrical resistivity tomography (ERT) was used to examine subsurface mixing dynamics. Different controls govern groundwater discharge at these sites. In areas with sporadic permafrost (Kasitsna Bay), the major driver of submarine groundwater discharge is tidal pumping, due to the large tidal oscillations, whereas at Point Barrow, a site with continuous permafrost and small tidal amplitudes, fluxes are mostly affected by seasonal permafrost thawing. Extended areas of low resistivity in the subsurface alongshore combined with high radon in surface water suggests that groundwater-surface water interactions might enhance heat transport into deeper permafrost layers promoting permafrost thawing, thereby enhancing groundwater discharge.
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Affiliation(s)
- Natasha T Dimova
- Department of Geological Sciences, University of Alabama , Tuscaloosa, Alabama 35487, United States
| | | | - John D Kessler
- Department of Earth and Environmental Sciences, University of Rochester , Rochester, New York 14627, United States
| | - Katy J Sparrow
- Department of Earth and Environmental Sciences, University of Rochester , Rochester, New York 14627, United States
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MacMillan GA, Girard C, Chételat J, Laurion I, Amyot M. High Methylmercury in Arctic and Subarctic Ponds is Related to Nutrient Levels in the Warming Eastern Canadian Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7743-53. [PMID: 26030209 DOI: 10.1021/acs.est.5b00763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L(-1)). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3-2.2 ng L(-1)) than polygonal ponds (0.1-0.3 ng L(-1)) or lakes (<0.1 ng L(-1)). High MeHg was measured in the bottom waters of Subarctic thaw ponds near Kuujjuarapik (0.1-3.1 ng L(-1)). High water MeHg concentrations in thaw ponds were strongly correlated with variables associated with high inputs of organic matter (DOC, a320, Fe), nutrients (TP, TN), and microbial activity (dissolved CO2 and CH4). Thawing permafrost due to Arctic warming will continue to release nutrients and organic carbon into these systems and increase ponding in some regions, likely stimulating higher water concentrations of MeHg. Greater hydrological connectivity from permafrost thawing may potentially increase transport of MeHg from thaw ponds to neighboring aquatic ecosystems.
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Affiliation(s)
- Gwyneth A MacMillan
- †Centre d'études nordiques, Département de sciences biologiques, Université de Montréal, Montreal, Quebec Canada, H2V 2S9
| | - Catherine Girard
- †Centre d'études nordiques, Département de sciences biologiques, Université de Montréal, Montreal, Quebec Canada, H2V 2S9
| | - John Chételat
- ‡Environment Canada, National Wildlife Research Centre, Ottawa, Ontario Canada, K1A 0H3
| | - Isabelle Laurion
- §Centre d'études nordiques, Institut national de la recherche scientifique, Centre Eau, Terre et Environnement, Québec, Quebec Canada, G1K 9A9
| | - Marc Amyot
- †Centre d'études nordiques, Département de sciences biologiques, Université de Montréal, Montreal, Quebec Canada, H2V 2S9
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