Autochthonous and allochthonous contributions of organic carbon to microbial food webs in Svalbard fjords

Handle URI:
http://hdl.handle.net/10754/623071
Title:
Autochthonous and allochthonous contributions of organic carbon to microbial food webs in Svalbard fjords
Authors:
Holding, Johnna M.; Duarte, Carlos M. ( 0000-0002-1213-1361 ) ; Delgado-Huertas, Antonio; Soetaert, Karline; Vonk, Jorien E.; Agusti, Susana ( 0000-0003-0536-7293 ) ; Wassmann, Paul; Middelburg, Jack J.
Abstract:
Rising temperatures in the Arctic Ocean are causing sea ice and glaciers to melt at record breaking rates, which has consequences for carbon cycling in the Arctic Ocean that are yet to be fully understood. Microbial carbon cycling is driven by internal processing of in situ produced organic carbon (OC), however recent research suggests that melt water from sea ice and glaciers could introduce an allochthonous source of OC to the microbial food web with ramifications for the metabolic balance of plankton communities. In this study, we characterized autochthonous and allochthonous sources of OC to the Western Svalbard fjord system using stable isotopes of carbon. We quantified δ13C of eukaryotic and prokaryotic planktonic groups using polar lipid-derived fatty acids as biomarkers in addition to measuring δ13C of marine particulate OC and dissolved OC from glacial runoff. δ13C of bacteria (−22.5‰) was higher than that of glacial runoff OC (−28.5‰) and other phytoplankton groups (−24.7 to −29.1‰), which suggests that marine bacteria preferentially use a third source of OC. We present a Bayesian three-source δ13C mixing model whereby ∼ 60% of bacteria carbon is derived from OC in sea ice, and the remaining carbon is derived from autochthonous production and glacial-derived OC. These results suggest that subsidies of OC from melting glaciers will not likely influence microbial carbon cycling in Svalbard fjords in the future and that further research is needed to determine the effects of melting sea ice on microbial carbon cycling in fjord systems and elsewhere in the Arctic Ocean.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Holding JM, Duarte CM, Delgado-Huertas A, Soetaert K, Vonk JE, et al. (2017) Autochthonous and allochthonous contributions of organic carbon to microbial food webs in Svalbard fjords. Limnology and Oceanography. Available: http://dx.doi.org/10.1002/lno.10526.
Publisher:
Wiley-Blackwell
Journal:
Limnology and Oceanography
Issue Date:
27-Mar-2017
DOI:
10.1002/lno.10526
Type:
Article
ISSN:
0024-3590
Sponsors:
We thank the captain and crew of the R/V Helmer Hanssen, J.C. Alonso for nutrient measurements, A. Dorsett for assistance with DOC measurements, Pieter van Rijswijk and Peter van Breugel for assistance with PLFA analysis and measurements, the Royal Netherlands Institute for Sea research (NIOZ) in Yerseke for accommodation, laboratory space, and technical support, and D. van Oevelen for coordinating analyses at NIOZ. This research was supported by the ARCTICMED project funded by the Spanish Ministry of Economy and Inovation (ref. CTM2011-15792-E) and the Netherlands Earth System Science Center. J.H. was supported by a JAE fellowship (CSIC, Spain).
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1002/lno.10526/full
Appears in Collections:
Articles; Red Sea Research Center (RSRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorHolding, Johnna M.en
dc.contributor.authorDuarte, Carlos M.en
dc.contributor.authorDelgado-Huertas, Antonioen
dc.contributor.authorSoetaert, Karlineen
dc.contributor.authorVonk, Jorien E.en
dc.contributor.authorAgusti, Susanaen
dc.contributor.authorWassmann, Paulen
dc.contributor.authorMiddelburg, Jack J.en
dc.date.accessioned2017-04-10T07:49:49Z-
dc.date.available2017-04-10T07:49:49Z-
dc.date.issued2017-03-27en
dc.identifier.citationHolding JM, Duarte CM, Delgado-Huertas A, Soetaert K, Vonk JE, et al. (2017) Autochthonous and allochthonous contributions of organic carbon to microbial food webs in Svalbard fjords. Limnology and Oceanography. Available: http://dx.doi.org/10.1002/lno.10526.en
dc.identifier.issn0024-3590en
dc.identifier.doi10.1002/lno.10526en
dc.identifier.urihttp://hdl.handle.net/10754/623071-
dc.description.abstractRising temperatures in the Arctic Ocean are causing sea ice and glaciers to melt at record breaking rates, which has consequences for carbon cycling in the Arctic Ocean that are yet to be fully understood. Microbial carbon cycling is driven by internal processing of in situ produced organic carbon (OC), however recent research suggests that melt water from sea ice and glaciers could introduce an allochthonous source of OC to the microbial food web with ramifications for the metabolic balance of plankton communities. In this study, we characterized autochthonous and allochthonous sources of OC to the Western Svalbard fjord system using stable isotopes of carbon. We quantified δ13C of eukaryotic and prokaryotic planktonic groups using polar lipid-derived fatty acids as biomarkers in addition to measuring δ13C of marine particulate OC and dissolved OC from glacial runoff. δ13C of bacteria (−22.5‰) was higher than that of glacial runoff OC (−28.5‰) and other phytoplankton groups (−24.7 to −29.1‰), which suggests that marine bacteria preferentially use a third source of OC. We present a Bayesian three-source δ13C mixing model whereby ∼ 60% of bacteria carbon is derived from OC in sea ice, and the remaining carbon is derived from autochthonous production and glacial-derived OC. These results suggest that subsidies of OC from melting glaciers will not likely influence microbial carbon cycling in Svalbard fjords in the future and that further research is needed to determine the effects of melting sea ice on microbial carbon cycling in fjord systems and elsewhere in the Arctic Ocean.en
dc.description.sponsorshipWe thank the captain and crew of the R/V Helmer Hanssen, J.C. Alonso for nutrient measurements, A. Dorsett for assistance with DOC measurements, Pieter van Rijswijk and Peter van Breugel for assistance with PLFA analysis and measurements, the Royal Netherlands Institute for Sea research (NIOZ) in Yerseke for accommodation, laboratory space, and technical support, and D. van Oevelen for coordinating analyses at NIOZ. This research was supported by the ARCTICMED project funded by the Spanish Ministry of Economy and Inovation (ref. CTM2011-15792-E) and the Netherlands Earth System Science Center. J.H. was supported by a JAE fellowship (CSIC, Spain).en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1002/lno.10526/fullen
dc.rightsArchived with thanks to Limnology and Oceanographyen
dc.titleAutochthonous and allochthonous contributions of organic carbon to microbial food webs in Svalbard fjordsen
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalLimnology and Oceanographyen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Global Change Research; Instituto Mediterráneo de Estudios Avanzados (CSIC- Univ. Islas Balears); Esporles Spainen
dc.contributor.institutionArctic Research Centre, Bioscience, Aarhus University; Aarhus C Denmarken
dc.contributor.institutionFaculty of Biosciences; Fisheries and Economics, UiT, The Arctic University of Norway; Tromso, Norwayen
dc.contributor.institutionLaboratorio de Biogeoquímica de Isótopos Estables, Instituto Andaluz de Ciencias de la Tierra (CSIC-Univ. Granada); Granada Spainen
dc.contributor.institutionDepartment of Estuarine and Delta Systems; Royal Netherlands Institute for Sea Research; Yerseke The Netherlandsen
dc.contributor.institutionFaculty of Earth and Life Science; Department of Earth Sciences, Vrije Universiteit; Amsterdam The Netherlandsen
dc.contributor.institutionFaculty of Geosciences; Department of Earth Sciences, University of Utrecht; Utrecht The Netherlandsen
kaust.authorDuarte, Carlos M.en
kaust.authorAgusti, Susanaen
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