Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea
Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >0.22 µ m), colloidal (0.22...
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ftdoajarticles:oai:doaj.org/article:b202a9a17dde4feeb56222a4cd58eab7 2023-05-15T15:00:52+02:00 Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea S. Conrad J. Ingri J. Gelting F. Nordblad E. Engström I. Rodushkin P. S. Andersson D. Porcelli Ö. Gustafsson I. Semiletov B. Öhlander 2019-03-01T00:00:00Z https://doi.org/10.5194/bg-16-1305-2019 https://doaj.org/article/b202a9a17dde4feeb56222a4cd58eab7 EN eng Copernicus Publications https://www.biogeosciences.net/16/1305/2019/bg-16-1305-2019.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-16-1305-2019 1726-4170 1726-4189 https://doaj.org/article/b202a9a17dde4feeb56222a4cd58eab7 Biogeosciences, Vol 16, Pp 1305-1319 (2019) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/bg-16-1305-2019 2022-12-31T07:27:50Z Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >0.22 µ m), colloidal (0.22 µ m–1 kDa), and truly dissolved ( <1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57 µ M with Fe dominantly as particulate Fe. The loss of >99 % of particulate Fe and about 90 % of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ 56 Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ 56 Fe values close to the river mouth (about −0.20 ‰) and positive δ 56 Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ 56 Fe values, representing chemically reactive ferrihydrites. The positive δ 56 Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ 56 Fe composition in the Arctic Ocean. Article in Journal/Newspaper Arctic Arctic Ocean laptev Laptev Sea lena river Directory of Open Access Journals: DOAJ Articles Arctic Arctic Ocean Laptev Sea Biogeosciences 16 6 1305 1319 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
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 S. Conrad J. Ingri J. Gelting F. Nordblad E. Engström I. Rodushkin P. S. Andersson D. Porcelli Ö. Gustafsson I. Semiletov B. Öhlander Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >0.22 µ m), colloidal (0.22 µ m–1 kDa), and truly dissolved ( <1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57 µ M with Fe dominantly as particulate Fe. The loss of >99 % of particulate Fe and about 90 % of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ 56 Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ 56 Fe values close to the river mouth (about −0.20 ‰) and positive δ 56 Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ 56 Fe values, representing chemically reactive ferrihydrites. The positive δ 56 Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ 56 Fe composition in the Arctic Ocean. |
format |
Article in Journal/Newspaper |
author |
S. Conrad J. Ingri J. Gelting F. Nordblad E. Engström I. Rodushkin P. S. Andersson D. Porcelli Ö. Gustafsson I. Semiletov B. Öhlander |
author_facet |
S. Conrad J. Ingri J. Gelting F. Nordblad E. Engström I. Rodushkin P. S. Andersson D. Porcelli Ö. Gustafsson I. Semiletov B. Öhlander |
author_sort |
S. Conrad |
title |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_short |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_full |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_fullStr |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_full_unstemmed |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_sort |
distribution of fe isotopes in particles and colloids in the salinity gradient along the lena river plume, laptev sea |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/bg-16-1305-2019 https://doaj.org/article/b202a9a17dde4feeb56222a4cd58eab7 |
geographic |
Arctic Arctic Ocean Laptev Sea |
geographic_facet |
Arctic Arctic Ocean Laptev Sea |
genre |
Arctic Arctic Ocean laptev Laptev Sea lena river |
genre_facet |
Arctic Arctic Ocean laptev Laptev Sea lena river |
op_source |
Biogeosciences, Vol 16, Pp 1305-1319 (2019) |
op_relation |
https://www.biogeosciences.net/16/1305/2019/bg-16-1305-2019.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-16-1305-2019 1726-4170 1726-4189 https://doaj.org/article/b202a9a17dde4feeb56222a4cd58eab7 |
op_doi |
https://doi.org/10.5194/bg-16-1305-2019 |
container_title |
Biogeosciences |
container_volume |
16 |
container_issue |
6 |
container_start_page |
1305 |
op_container_end_page |
1319 |
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1766332914941820928 |