The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study
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 repor...
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Stockholms universitet, Institutionen för geologiska vetenskaper
2017
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-139809 https://doi.org/10.5194/bg-14-285-2017 |
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ftstockholmuniv:oai:DiVA.org:su-139809 2023-05-15T15:18:10+02:00 The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study Bonaglia, Stefano Hylén, Astrid Rattray, Jayne E. Kononets, Mikhail Y. Ekeroth, Nils Roos, Per Thamdrup, Bo Brüchert, Volker Hall, Per O. J. 2017 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-139809 https://doi.org/10.5194/bg-14-285-2017 eng eng Stockholms universitet, Institutionen för geologiska vetenskaper Biogeosciences, 1726-4170, 2017, 14:2, s. 285-300 orcid:0000-0003-4366-0677 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-139809 doi:10.5194/bg-14-285-2017 ISI:000394446000001 info:eu-repo/semantics/openAccess Geochemistry Geokemi Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Geosciences Multidisciplinary Multidisciplinär geovetenskap Article in journal info:eu-repo/semantics/article text 2017 ftstockholmuniv https://doi.org/10.5194/bg-14-285-2017 2023-02-23T21:43:37Z 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 ... Article in Journal/Newspaper Arctic Subarctic Stockholm University: Publications (DiVA) Arctic Biogeosciences 14 2 285 300 |
institution |
Open Polar |
collection |
Stockholm University: Publications (DiVA) |
op_collection_id |
ftstockholmuniv |
language |
English |
topic |
Geochemistry Geokemi Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Geosciences Multidisciplinary Multidisciplinär geovetenskap |
spellingShingle |
Geochemistry Geokemi Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Geosciences Multidisciplinary Multidisciplinär geovetenskap Bonaglia, Stefano Hylén, Astrid Rattray, Jayne E. Kononets, Mikhail Y. Ekeroth, Nils Roos, Per Thamdrup, Bo Brüchert, Volker Hall, Per O. J. The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
topic_facet |
Geochemistry Geokemi Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Geosciences Multidisciplinary Multidisciplinär geovetenskap |
description |
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 ... |
format |
Article in Journal/Newspaper |
author |
Bonaglia, Stefano Hylén, Astrid Rattray, Jayne E. Kononets, Mikhail Y. Ekeroth, Nils Roos, Per Thamdrup, Bo Brüchert, Volker Hall, Per O. J. |
author_facet |
Bonaglia, Stefano Hylén, Astrid Rattray, Jayne E. Kononets, Mikhail Y. Ekeroth, Nils Roos, Per Thamdrup, Bo Brüchert, Volker Hall, Per O. J. |
author_sort |
Bonaglia, Stefano |
title |
The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
title_short |
The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
title_full |
The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
title_fullStr |
The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
title_full_unstemmed |
The fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
title_sort |
fate of fixed nitrogen in marine sediments with low organic loading : an in situ study |
publisher |
Stockholms universitet, Institutionen för geologiska vetenskaper |
publishDate |
2017 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-139809 https://doi.org/10.5194/bg-14-285-2017 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Subarctic |
genre_facet |
Arctic Subarctic |
op_relation |
Biogeosciences, 1726-4170, 2017, 14:2, s. 285-300 orcid:0000-0003-4366-0677 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-139809 doi:10.5194/bg-14-285-2017 ISI:000394446000001 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-14-285-2017 |
container_title |
Biogeosciences |
container_volume |
14 |
container_issue |
2 |
container_start_page |
285 |
op_container_end_page |
300 |
_version_ |
1766348398949040128 |