Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
The fate of fixed nitrogen in marine sediments with low organic loading: an in situ study
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.ORCID-id: 0000-0003-4366-0677
Visa övriga samt affilieringar
2017 (Engelska)Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 14, nr 2, s. 285-300Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Over the last decades, the impact of human activities on the global nitrogen (N) cycle has drastically increased. Consequently, benthic N cycling has mainly been studied in anthropogenically impacted estuaries and coasts, while in oligotrophic systems its understanding is still scarce. Here we report on benthic solute fluxes and on rates of denitrification, anammox, and dissimilatory nitrate reduction to ammonium (DNRA) studied by in situ incubations with benthic chamber landers during two cruises to the Gulf of Bothnia (GOB), a cold, oligotrophic basin located in the northern part of the Baltic Sea. Rates of N burial were also inferred to investigate the fate of fixed N in these sediments. Most of the total dissolved fixed nitrogen (TDN) diffusing to the water column was composed of organic N. Average rates of dinitrogen (N-2) production by denitrification and anammox (range: 53-360 mu mol Nm(-2) day(-1)) were comparable to those from Arctic and subarctic sediments worldwide (range: 34-344 mu mol Nm(-2) day(-1)). Anammox accounted for 18-26% of the total N2 production. Absence of free hydrogen sulfide and low concentrations of dissolved iron in sediment pore water suggested that denitrification and DNRA were driven by organic matter oxidation rather than chemolithotrophy. DNRA was as important as denitrification at a shallow, coastal station situated in the northern Bothnian Bay. At this pristine and fully oxygenated site, ammonium regeneration through DNRA contributed more than one-third to the TDN efflux and accounted, on average, for 45% of total nitrate reduction. At the offshore stations, the proportion of DNRA in relation to denitrification was lower (0-16% of total nitrate reduction). Median value and range of benthic DNRA rates from the GOB were comparable to those from the southern and central eutrophic Baltic Sea and other temperate estuaries and coasts in Europe. Therefore, our results contrast with the view that DNRA is negligible in cold and well-oxygenated sediments with low organic carbon loading. However, the mechanisms behind the variability in DNRA rates between our sites were not resolved. The GOB sediments were a major source (237 kt yr(-1), which corresponds to 184% of the external N load) of fixed N to the water column through recycling mechanisms. To our knowledge, our study is the first to document the simultaneous contribution of denitrification, DNRA, anammox, and TDN recycling combined with in situ measurements.

Ort, förlag, år, upplaga, sidor
2017. Vol. 14, nr 2, s. 285-300
Nationell ämneskategori
Geokemi Oceanografi, hydrologi och vattenresurser Multidisciplinär geovetenskap
Forskningsämne
biogeokemi; oceanografi; marin geovetenskap
Identifikatorer
URN: urn:nbn:se:su:diva-139809DOI: 10.5194/bg-14-285-2017ISI: 000394446000001OAI: oai:DiVA.org:su-139809DiVA, id: diva2:1074673
Tillgänglig från: 2017-02-15 Skapad: 2017-02-15 Senast uppdaterad: 2018-01-13Bibliografiskt granskad

Open Access i DiVA

fulltext(1969 kB)127 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 1969 kBChecksumma SHA-512
0358791976bd824a00bb2a82d219f1a50b92d3ef2361c9a02ad27e846d1368271b9d4611cdaa5c77704f6d86a673cf276dc52dd4a2bfdb93baae6c7d0ce3adf7
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltext

Sök vidare i DiVA

Av författaren/redaktören
Bonaglia, Stefano
Av organisationen
Institutionen för geologiska vetenskaper
I samma tidskrift
Biogeosciences
GeokemiOceanografi, hydrologi och vattenresurserMultidisciplinär geovetenskap

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 127 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 537 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf