Evidence of high N2 fixation rates in the temperate northeast Atlantic
Diazotrophic activity and primary production (PP) were investigated along two transects (Belgica BG2014/14 and GEOVIDE cruises) off the western Iberian Margin and the Bay of Biscay in May 2014. Substantial N2 fixation activity was observed at 8 of the 10 stations sampled, ranging overall from 81 to...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/332762 2023-08-20T04:08:41+02:00 Evidence of high N2 fixation rates in the temperate northeast Atlantic Fonseca-Batista, Debany Li, Xuefeng Riou, Virginie Michotey, Valérie Deman, Florian Fripiat, François Guasco, Sophie Brion, Natacha Lemaitre, Nolwenn Tonnard, Manon Gallinari, Morgane Planquette, Hélène Planchon, Frédéric Sarthou, Géraldine Elskens, Marc LaRoche, Julie Chou, Lei Dehairs, Frank 2019-03-13 application/application/pdf https://hdl.handle.net/20.500.11850/332762 https://doi.org/10.3929/ethz-b-000332762 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-16-999-2019 info:eu-repo/semantics/altIdentifier/wos/000461174100003 http://hdl.handle.net/20.500.11850/332762 doi:10.3929/ethz-b-000332762 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International Biogeosciences, 16 (5) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2019 ftethz https://doi.org/20.500.11850/33276210.3929/ethz-b-00033276210.5194/bg-16-999-2019 2023-07-30T23:50:06Z Diazotrophic activity and primary production (PP) were investigated along two transects (Belgica BG2014/14 and GEOVIDE cruises) off the western Iberian Margin and the Bay of Biscay in May 2014. Substantial N2 fixation activity was observed at 8 of the 10 stations sampled, ranging overall from 81 to 384 µmol N m−2 d−1 (0.7 to 8.2 nmol N L−1 d−1), with two sites close to the Iberian Margin situated between 38.8 and 40.7∘ N yielding rates reaching up to 1355 and 1533 µmol N m−2 d−1. Primary production was relatively lower along the Iberian Margin, with rates ranging from 33 to 59 mmol C m−2 d−1, while it increased towards the northwest away from the peninsula, reaching as high as 135 mmol C m−2 d−1. In agreement with the area-averaged Chl a satellite data contemporaneous with our study period, our results revealed that post-bloom conditions prevailed at most sites, while at the northwesternmost station the bloom was still ongoing. When converted to carbon uptake using Redfield stoichiometry, N2 fixation could support 1 % to 3 % of daily PP in the euphotic layer at most sites, except at the two most active sites where this contribution to daily PP could reach up to 25 %. At the two sites where N2 fixation activity was the highest, the prymnesiophyte–symbiont Candidatus Atelocyanobacterium thalassa (UCYN-A) dominated the nifH sequence pool, while the remaining recovered sequences belonged to non-cyanobacterial phylotypes. At all the other sites, however, the recovered nifH sequences were exclusively assigned phylogenetically to non-cyanobacterial phylotypes. The intense N2 fixation activities recorded at the time of our study were likely promoted by the availability of phytoplankton-derived organic matter produced during the spring bloom, as evidenced by the significant surface particulate organic carbon concentrations. Also, the presence of excess phosphorus signature in surface waters seemed to contribute to sustaining N2 fixation, particularly at the sites with extreme activities. These results provide a ... Article in Journal/Newspaper Northeast Atlantic ETH Zürich Research Collection |
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Open Polar |
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ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
Diazotrophic activity and primary production (PP) were investigated along two transects (Belgica BG2014/14 and GEOVIDE cruises) off the western Iberian Margin and the Bay of Biscay in May 2014. Substantial N2 fixation activity was observed at 8 of the 10 stations sampled, ranging overall from 81 to 384 µmol N m−2 d−1 (0.7 to 8.2 nmol N L−1 d−1), with two sites close to the Iberian Margin situated between 38.8 and 40.7∘ N yielding rates reaching up to 1355 and 1533 µmol N m−2 d−1. Primary production was relatively lower along the Iberian Margin, with rates ranging from 33 to 59 mmol C m−2 d−1, while it increased towards the northwest away from the peninsula, reaching as high as 135 mmol C m−2 d−1. In agreement with the area-averaged Chl a satellite data contemporaneous with our study period, our results revealed that post-bloom conditions prevailed at most sites, while at the northwesternmost station the bloom was still ongoing. When converted to carbon uptake using Redfield stoichiometry, N2 fixation could support 1 % to 3 % of daily PP in the euphotic layer at most sites, except at the two most active sites where this contribution to daily PP could reach up to 25 %. At the two sites where N2 fixation activity was the highest, the prymnesiophyte–symbiont Candidatus Atelocyanobacterium thalassa (UCYN-A) dominated the nifH sequence pool, while the remaining recovered sequences belonged to non-cyanobacterial phylotypes. At all the other sites, however, the recovered nifH sequences were exclusively assigned phylogenetically to non-cyanobacterial phylotypes. The intense N2 fixation activities recorded at the time of our study were likely promoted by the availability of phytoplankton-derived organic matter produced during the spring bloom, as evidenced by the significant surface particulate organic carbon concentrations. Also, the presence of excess phosphorus signature in surface waters seemed to contribute to sustaining N2 fixation, particularly at the sites with extreme activities. These results provide a ... |
format |
Article in Journal/Newspaper |
author |
Fonseca-Batista, Debany Li, Xuefeng Riou, Virginie Michotey, Valérie Deman, Florian Fripiat, François Guasco, Sophie Brion, Natacha Lemaitre, Nolwenn Tonnard, Manon Gallinari, Morgane Planquette, Hélène Planchon, Frédéric Sarthou, Géraldine Elskens, Marc LaRoche, Julie Chou, Lei Dehairs, Frank |
spellingShingle |
Fonseca-Batista, Debany Li, Xuefeng Riou, Virginie Michotey, Valérie Deman, Florian Fripiat, François Guasco, Sophie Brion, Natacha Lemaitre, Nolwenn Tonnard, Manon Gallinari, Morgane Planquette, Hélène Planchon, Frédéric Sarthou, Géraldine Elskens, Marc LaRoche, Julie Chou, Lei Dehairs, Frank Evidence of high N2 fixation rates in the temperate northeast Atlantic |
author_facet |
Fonseca-Batista, Debany Li, Xuefeng Riou, Virginie Michotey, Valérie Deman, Florian Fripiat, François Guasco, Sophie Brion, Natacha Lemaitre, Nolwenn Tonnard, Manon Gallinari, Morgane Planquette, Hélène Planchon, Frédéric Sarthou, Géraldine Elskens, Marc LaRoche, Julie Chou, Lei Dehairs, Frank |
author_sort |
Fonseca-Batista, Debany |
title |
Evidence of high N2 fixation rates in the temperate northeast Atlantic |
title_short |
Evidence of high N2 fixation rates in the temperate northeast Atlantic |
title_full |
Evidence of high N2 fixation rates in the temperate northeast Atlantic |
title_fullStr |
Evidence of high N2 fixation rates in the temperate northeast Atlantic |
title_full_unstemmed |
Evidence of high N2 fixation rates in the temperate northeast Atlantic |
title_sort |
evidence of high n2 fixation rates in the temperate northeast atlantic |
publisher |
Copernicus |
publishDate |
2019 |
url |
https://hdl.handle.net/20.500.11850/332762 https://doi.org/10.3929/ethz-b-000332762 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_source |
Biogeosciences, 16 (5) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-16-999-2019 info:eu-repo/semantics/altIdentifier/wos/000461174100003 http://hdl.handle.net/20.500.11850/332762 doi:10.3929/ethz-b-000332762 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/33276210.3929/ethz-b-00033276210.5194/bg-16-999-2019 |
_version_ |
1774721109197848576 |