{"refrec":{"BRefID":295476,"RR":"<b>Borges, A.V.; Abril, G.; Bouillon, S.</b> (2018). Carbon dynamics and CO<sub>2</sub> and CH<sub>4</sub> outgassing in the Mekong delta. <i>Biogeosciences 15(4)</i>: 1093-1114. <a href=\"https://dx.doi.org/10.5194/bg-15-1093-2018\" target=\"_blank\">https://dx.doi.org/10.5194/bg-15-1093-2018</a>","BEntID":287563,"PublicFlag":1,"CheckedFlag":1,"wosflag":1,"vabbflag":1,"RefStringPartII":". <i>Biogeosciences 15(4)</i>: 1093-1114. <a href=\"https://dx.doi.org/10.5194/bg-15-1093-2018\" target=\"_blank\">https://dx.doi.org/10.5194/bg-15-1093-2018</a>","DocTypID":8,"DocType":"Journal article","MarineFlag":1,"FreshFlag":0,"BrackishFlag":0,"TerrestrialFlag":0,"Authorstring":"Borges, A.V.; Abril, G.; Bouillon, S.","OrigTitleTranslFlag":0,"Authorstringtrunc":"Borges, A.V. <i>et al.</i>","Englishabstract":"We report a data set of biogeochemical variables related to carbon cycling obtained in the three branches (Mỹ Tho, Hàm Luông, Cố Chiên) of the Mekong delta (Bến Tre province, Vietnam) in December&nbsp;2003, April&nbsp;2004, and October&nbsp;2004. Both the inner estuary (upstream of the mouth) and the outer estuary (river plume) were sampled, as well as side channels. The values of the partial pressure of CO<sub>2</sub> (pCO<sub>2</sub>) ranged between 232 and 4085 ppm, O<sub>2</sub> saturation level (%O<sub>2</sub>) between 63 and 114 %, and CH<sub>4</sub> between 2 and 2217 nmol L<sup>−1</sup>, within the ranges of values previously reported in temperate and tropical meso- and macro-tidal estuaries. Strong seasonal variations were observed. In the upper oligohaline estuary, low pCO<sub>2</sub> (479–753 ppm) and high %O<sub>2</sub> (98–106 %) values were observed in April&nbsp;2004 most probably related to freshwater phytoplankton growth owing to low freshwater discharge (1400 m<sup>3</sup> s<sup>−1</sup>) and increase in water residence time; during the two other sampling periods with a higher freshwater discharge (9300–17 900 m<sup>3</sup> s<sup>−1</sup>), higher pCO<sub>2</sub> (1895–2664 ppm) and lower %O<sub>2</sub> (69–84 %) values were observed in the oligohaline part of the estuary. In October&nbsp;2004, important phytoplankton growth occurred in the offshore part of the river plume as attested by changes in the contribution of particulate organic carbon (POC) to total suspended matter (TSM) (%POC) and the stable isotope composition of POC (<i>δ</i><sup>13</sup>C-POC), possibly related to low TSM values (improvement of light conditions for phytoplankton development), leading to low pCO<sub>2</sub> (232 ppm) and high %O<sub>2</sub> (114 %) values. Water in the side channels in the Mekong delta was strongly impacted by inputs from the extensive shrimp farming ponds. The values of pCO<sub>2</sub>, CH<sub>4</sub>, %O<sub>2</sub>, and the stable isotope composition of dissolved inorganic carbon (<i>δ</i><sup>13</sup>C-DIC) indicated intense organic matter degradation that was partly mediated by sulfate reduction in sediments, as revealed by the slope of total alkalinity (TA) and DIC covariations. The <i>δ</i><sup>13</sup>C-POC variations also indicated intense phytoplankton growth in the side channels, presumably due to nutrient enrichment related to the shrimp farming ponds. A data set in the mangrove creeks of the Ca Mau province (part of the Mekong delta) was also acquired in April and October&nbsp;2004. These data extended the range of variability in pCO<sub>2</sub> and %O<sub>2</sub> with more extreme values than in the Mekong delta (Bến Tre), with maxima and minima of 6912 ppm and 37 %, respectively. Similarly, the maximum CH<sub>4</sub> concentration (686 nmol L<sup>−1</sup>) was higher in the Ca Mau province mangrove creeks than in the Mekong delta (Bến Tre, maximum 222 nmol L<sup>−1</sup>) during the October&nbsp;2004 cruise (rainy season and high freshwater discharge period). In April&nbsp;2004 (dry season and low freshwater discharge period), the CH<sub>4</sub> values were much lower than in October&nbsp;2004 (average 19 ± 13 and 210 ± 158 nmol L<sup>−1</sup>, respectively) in the Ca Mau province mangrove creeks, owing to the higher salinity (average 33.2 ± 0.6 and 14.1 ± 1.2, respectively) that probably led to higher sediment sulfate reduction, leading to inhibition of sediment methanogenesis and higher anaerobic CH<sub>4</sub> oxidation. In the inner estuarine region (three branches of the Mekong delta), CO<sub>2</sub> emissions to the atmosphere averaged 121 mmol m<sup>−2</sup> d<sup>−1</sup>, and the CH<sub>4</sub> emissions averaged 118 µmol m<sup>−2</sup> d<sup>−1</sup>. The CO<sub>2</sub> emission to the atmosphere from the Mekong inner estuary was higher than reported in the Yangtze and Pearl river inner estuaries. This was probably due to the lower salinity in the Mekong delta branches, possibly due to different morphology: relatively linear channels in the Mekong delta versus funnel-shaped estuaries for the Yangtze and Pearl river inner estuaries.","AbstractOtherLang":null,"BibLvlCode":"AS","StandardTitle":"Carbon dynamics and CO<sub>2</sub> and CH<sub>4</sub> outgassing in the Mekong delta","OrigTitleLangCode":"en","OrigTitleLangCodeExtended":"eng","OrigTitleLangID":15,"DateLastModified":{"date":"2024-12-10 01:33:17.368041","timezone_type":1,"timezone":"+01:00"},"UserAccessRight":null,"UserAccID":null,"AuthorKeywords":null,"OtherDescriptors":null,"Notes":null,"AnaPub":2018,"MonPub":null,"DateUpdate":"2018-05-16","DateCreate":"2018-05-15","SecASFANote":null,"ConfID":null,"PeerRev":1,"VlizCoreFlag":1,"WoScode":"WOS:000425784800002","VABBcode":null,"OpenAcc":1,"DOI":"10.5194/bg-15-1093-2018"},"refs":null,"anarec":{"AnaID":295476,"PubliDate":2018,"Pagination":"1093-1114","XtraPublOfAnaID":null,"ISBN":null,"Volume":"15","Issue":"4","BRefMon":null,"BRefMonRR":null,"BRefXtra":null,"BRefXtraRR":null,"SerBRefID":68092,"SerRR":"<b>Gattuso, J.P.; Kesselmeier, J. (Ed.)</b> Biogeosciences. Copernicus Publications: Göttingen.  ISSN 1726-4170; e-ISSN 1726-4189","StandardTitleSer":"Biogeosciences","ISSN":"1726-4170","AbbrevSer":"Biogeosciences","StandardTitleMon":null,"StartPage":1093,"Pages":22,"ToPubliDate":null,"BRefBibLvlCode":"S","SerNotes":null},"monrec":null,"serrec":null,"relations":null,"relationsRev":null,"addrec":null,"othpubs":null,"ownerships":null,"authors":[{"AutName":"Borges","Firstname":"Alberto Vieira","Initials":"A.V.","Affiliation":"Chemical Oceanography Unit, University of Liège","Discriminator":null,"CorporateFlag":0,"BEntID":287563,"AutID":155348,"OrderNr":1,"DegrID":null,"EditorFlag":0,"CorrespFlag":0,"IllustratorFlag":0,"ReviserFlag":0,"TranslatorFlag":0,"InsAcronym":null,"InsFSN":"Université de Liège; Faculté des Sciences; Département d'Astrophysique, Géophysique et Océanographie; Unité d’Océanographie Chimique","ORCID":"0000-0002-5434-2247","PersID":3170,"InsID":153},{"AutName":"Abril","Firstname":"Gwenaël","Initials":"G.","Affiliation":null,"Discriminator":null,"CorporateFlag":0,"BEntID":287563,"AutID":157106,"OrderNr":2,"DegrID":null,"EditorFlag":0,"CorrespFlag":0,"IllustratorFlag":0,"ReviserFlag":0,"TranslatorFlag":0,"InsAcronym":null,"InsFSN":null,"ORCID":null,"PersID":661,"InsID":null},{"AutName":"Bouillon","Firstname":"Steven","Initials":"S.","Affiliation":"Department of Earth and Environmental Sciences, KU Leuven","Discriminator":null,"CorporateFlag":0,"BEntID":287563,"AutID":177718,"OrderNr":3,"DegrID":null,"EditorFlag":0,"CorrespFlag":0,"IllustratorFlag":0,"ReviserFlag":0,"TranslatorFlag":0,"InsAcronym":null,"InsFSN":"Katholieke Universiteit Leuven; Departement Aard- en Omgevingswetenschappen","ORCID":"0000-0001-7669-2929","PersID":2078,"InsID":4676}],"mapdetails":null,"datasets":null,"monographs":null,"monparts":null,"serparts":null,"BEntOpen":null,"BEntPrivate":null,"availability":[{"BInstID":313363,"LibID":36,"BRefID":295476,"EmbargoDate":null,"FullEmbargoDate":null,"PhysMedID":16,"hasOCRd":1,"ShelfLocCode":"313363","RFID":null,"PaidValue":null,"Medium":"Server","Description":"VLIZ Open Access","Acronym":"VLIZ","Library":"Vlaams Instituut voor de Zee","DutchTerm":"Open access","URL":null,"ClassifID":53,"Classification":"Open access","ReqLink":null,"ClassifTypID":1,"URLLocation":"https://www.vliz.be/imisdocs/publications/","SubDir":null,"InternalReq":0,"LoggedInReq":0,"Disclaimer":null,"DutchDisclaimer":null,"FileFormat":".pdf","FileDescr":"pdf","InsPub":1,"InsID":36,"FileFormID":6,"LendableFlag":1,"PublicFlag":1,"orderLib":"A","Notes":null,"AccConID":null,"AccessConstraint":null,"LicURL":null}],"litstyles":null,"thespers":null,"arch2discl":null,"SERpubls":[{"PublName":"Copernicus Publications","City":"Göttingen"}],"MONpubls":null,"pictures":[],"thestermsPath":null,"thestermsASFA":null,"taxtermsASFA":null,"geotermsASFA":null,"collections":[{"Collection":"OMA - Open Marien Archief","ShortName":"OMA"}],"conf":null,"proj":null,"Physdatasets":null,"spcols":{"222":{"SpName":"BMB - Belgische Mariene Bibliografie","SpColID":222,"ParSpColID":null,"TopParID":null,"ShortName":"BMB","URLLocation":null,"LibID":36,"OpenRepoFlag":null,"SpTypID":null,"TopParIDNotWebsite":null,"SpColPath":"BMB"},"221":{"SpName":"OMA - Open Marien Archief","SpColID":221,"ParSpColID":null,"TopParID":null,"ShortName":"OMA","URLLocation":null,"LibID":36,"OpenRepoFlag":1,"SpTypID":null,"TopParIDNotWebsite":null,"SpColPath":"OMA"}},"doi":null,"publs":null,"serparttypes":null,"monauthors":null,"MParts":null,"SParts":null,"hLibs":null,"langs":[{"BEntID":287563,"AbstractFlag":0,"LangID":15,"LangCode":"en","Lang":"English","DutchTerm":"Engels","LangCodeExtended":"eng"},{"BEntID":287563,"AbstractFlag":1,"LangID":15,"LangCode":"en","Lang":"English","DutchTerm":"Engels","LangCodeExtended":"eng"}],"urls":[{"URL":"https://dx.doi.org/10.5194/bg-15-1093-2018","externalID":"10.5194/bg-15-1093-2018","URLTypeCode":"DOI","URLID":64528,"URLTypID":13,"URLType":"DOI","URLPrefix":"http://dx.doi.org/"}],"thesterms":null,"taxterms":null,"geoterms":null,"othterms":null,"asfacodes":null,"asfa2codes":null,"thestermsFRIS":null,"taxtermsFRIS":null,"geotermsFRIS":null,"othtermsFRIS":null,"resmessage":"","complete":1,"sessions":{"newSesName":"Lyssens, Liesbeth, L.","newSesDate":{"date":"2018-05-15 12:32:46.633000","timezone_type":3,"timezone":"Europe/Brussels"},"updSesName":"Bouchti, Zohra, Z.","updSesDate":{"date":"2018-05-16 08:25:16.713000","timezone_type":3,"timezone":"Europe/Brussels"}}}