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dc.contributor.authorMarshall, Matthew G.
dc.contributor.authorKellerman, Anne M.
dc.contributor.authorWadham, Jemma Louise
dc.contributor.authorHawkings, Jon R.
dc.contributor.authorDaneri, Giovanni
dc.contributor.authorTorres, Rodrigo
dc.contributor.authorPryer, Helena V.
dc.contributor.authorBeaton, Alexander
dc.contributor.authorNg, Hong Chin
dc.contributor.authorUrra, Alejandra
dc.contributor.authorRobinson, Laura F.
dc.contributor.authorSpencer, Robert G.M.
dc.date.accessioned2021-07-04T19:25:51Z
dc.date.available2021-07-04T19:25:51Z
dc.date.issued2021-04-09
dc.description.abstractBiogeochemical processes in fjords are likely affected by changes in surrounding glacier cover but very little is known about how meltwater directly influences dissolved organic matter (DOM) in fjords. Moreover, the data available are restricted to a handful of northern hemisphere sites. Here we analyze seasonal and spatial variation in dissolved organic carbon (DOC) concentration and DOM composition (spectrofluorescence, ultrahigh resolution mass spectrometry) in Baker-Martinez Fjord, Chilean Patagonia (48°S), to infer the impacts of rapid regional deglaciation on fjord DOM. We show that surface layer DOC concentrations do not vary significantly between seasons, but DOM composition is sensitive to differences in riverine inputs. In summer, higher protein-like fluorescence reflects increased glacial meltwater inputs, whilst molecular level data show weaker influence from marine DOM due to more intense stratification. We postulate that the shifting seasonal balance of riverine and marine waters affects the supply of biolabile peptides and organic nitrogen cycling in the surface layer. Trends in DOM composition with increasing salinity are consistent with patterns in estuaries (i.e. preferential removal of aromatic compounds and increasing relative contribution of unsaturated and heteroatom-rich DOM from marine sources). Preliminary estimates also suggest that at least 10% of the annual organic carbon stock in this fjord is supplied by the four largest, glacially fed rivers and that these inputs are dominated by dissolved (84%) over particulate organic carbon. Riverine DOC may therefore be an important carbon subsidy to bacterial communities in the inner fjord. The overall findings highlight the biogeochemical sensitivity of a Patagonian fjord to changes in glacier melt input, which likely has relevance for other glaciated fjords in a warming climate.en_US
dc.identifier.citationMarshall, Kellerman, Wadham JL, Hawkings JR, Daneri G, Torres, Pryer, Beaton, Ng, Urra, Robinson LF, Spencer. Seasonal Changes in Dissolved Organic Matter Composition in a Patagonian Fjord Affected by Glacier Melt Inputs. Frontiers in Marine Science. 2021;8:1-21en_US
dc.identifier.cristinIDFRIDAID 1908656
dc.identifier.doi10.3389/fmars.2021.612386
dc.identifier.issn2296-7745
dc.identifier.urihttps://hdl.handle.net/10037/21713
dc.language.isoengen_US
dc.publisherFrontiers Mediaen_US
dc.relation.journalFrontiers in Marine Science
dc.relation.projectIDinfo:eu-repo/grantAgreement/EC/H2020/793962/EU/Iron and Carbon Interactions and Biogeochemical CycLing in Subglacial EcosystemS/ICICLES/en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2021 The Author(s)en_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450::Quaternary geology, glaciology: 465en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Kvartærgeologi, glasiologi: 465en_US
dc.titleSeasonal Changes in Dissolved Organic Matter Composition in a Patagonian Fjord Affected by Glacier Melt Inputsen_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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