Evidence of high N 2 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 N 2 fixation activity was observed at 8 of the 10 stations sampled, ranging overall from 81 to...
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ftdoajarticles:oai:doaj.org/article:bfa17371447942e380462d9b57c03f17 2023-05-15T17:41:44+02:00 Evidence of high N 2 fixation rates in the temperate northeast Atlantic D. Fonseca-Batista X. Li V. Riou V. Michotey F. Deman F. Fripiat S. Guasco N. Brion N. Lemaitre M. Tonnard M. Gallinari H. Planquette F. Planchon G. Sarthou M. Elskens J. LaRoche L. Chou F. Dehairs 2019-03-01T00:00:00Z https://doi.org/10.5194/bg-16-999-2019 https://doaj.org/article/bfa17371447942e380462d9b57c03f17 EN eng Copernicus Publications https://www.biogeosciences.net/16/999/2019/bg-16-999-2019.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-16-999-2019 1726-4170 1726-4189 https://doaj.org/article/bfa17371447942e380462d9b57c03f17 Biogeosciences, Vol 16, Pp 999-1017 (2019) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/bg-16-999-2019 2022-12-31T14:56:49Z 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 N 2 fixation activity was observed at 8 of the 10 stations sampled, ranging overall from 81 to 384 µ mol 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 µ mol 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, N 2 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 N 2 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 N 2 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 N 2 fixation, particularly at the sites with extreme activities. These ... Article in Journal/Newspaper Northeast Atlantic Directory of Open Access Journals: DOAJ Articles Biogeosciences 16 5 999 1017 |
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Directory of Open Access Journals: DOAJ Articles |
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language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 D. Fonseca-Batista X. Li V. Riou V. Michotey F. Deman F. Fripiat S. Guasco N. Brion N. Lemaitre M. Tonnard M. Gallinari H. Planquette F. Planchon G. Sarthou M. Elskens J. LaRoche L. Chou F. Dehairs Evidence of high N 2 fixation rates in the temperate northeast Atlantic |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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 N 2 fixation activity was observed at 8 of the 10 stations sampled, ranging overall from 81 to 384 µ mol 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 µ mol 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, N 2 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 N 2 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 N 2 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 N 2 fixation, particularly at the sites with extreme activities. These ... |
format |
Article in Journal/Newspaper |
author |
D. Fonseca-Batista X. Li V. Riou V. Michotey F. Deman F. Fripiat S. Guasco N. Brion N. Lemaitre M. Tonnard M. Gallinari H. Planquette F. Planchon G. Sarthou M. Elskens J. LaRoche L. Chou F. Dehairs |
author_facet |
D. Fonseca-Batista X. Li V. Riou V. Michotey F. Deman F. Fripiat S. Guasco N. Brion N. Lemaitre M. Tonnard M. Gallinari H. Planquette F. Planchon G. Sarthou M. Elskens J. LaRoche L. Chou F. Dehairs |
author_sort |
D. Fonseca-Batista |
title |
Evidence of high N 2 fixation rates in the temperate northeast Atlantic |
title_short |
Evidence of high N 2 fixation rates in the temperate northeast Atlantic |
title_full |
Evidence of high N 2 fixation rates in the temperate northeast Atlantic |
title_fullStr |
Evidence of high N 2 fixation rates in the temperate northeast Atlantic |
title_full_unstemmed |
Evidence of high N 2 fixation rates in the temperate northeast Atlantic |
title_sort |
evidence of high n 2 fixation rates in the temperate northeast atlantic |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/bg-16-999-2019 https://doaj.org/article/bfa17371447942e380462d9b57c03f17 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_source |
Biogeosciences, Vol 16, Pp 999-1017 (2019) |
op_relation |
https://www.biogeosciences.net/16/999/2019/bg-16-999-2019.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-16-999-2019 1726-4170 1726-4189 https://doaj.org/article/bfa17371447942e380462d9b57c03f17 |
op_doi |
https://doi.org/10.5194/bg-16-999-2019 |
container_title |
Biogeosciences |
container_volume |
16 |
container_issue |
5 |
container_start_page |
999 |
op_container_end_page |
1017 |
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1766143462801932288 |