Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea
Coastal acidification has been widely investigated in terms of its rationale and ecological effects in the last decade. However, the driving mechanism for acidification in open seawater, especially in mesopelagic water, is still poorly understood. Here, the sinking velocity and flux attenuation of p...
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ftdoajarticles:oai:doaj.org/article:b0a94335a37b4fe3ae158ec5126971bb 2023-05-15T17:51:48+02:00 Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea Weifeng Yang Xiufeng Zhao Minfang Zheng 2022-09-01T00:00:00Z https://doi.org/10.3389/fmars.2022.1018825 https://doaj.org/article/b0a94335a37b4fe3ae158ec5126971bb EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2022.1018825/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.1018825 https://doaj.org/article/b0a94335a37b4fe3ae158ec5126971bb Frontiers in Marine Science, Vol 9 (2022) ocean acidification biological pump POC export sinking velocity polonium-210 Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2022 ftdoajarticles https://doi.org/10.3389/fmars.2022.1018825 2022-12-31T00:04:23Z Coastal acidification has been widely investigated in terms of its rationale and ecological effects in the last decade. However, the driving mechanism for acidification in open seawater, especially in mesopelagic water, is still poorly understood. Here, the sinking velocity and flux attenuation of particulate organic carbon (POC) were examined based upon the radioactive 210Po-210Pb tracer to reveal the remineralization of POC in the mesopelagic zone in the northeastern South China Sea (SCS). Overall, the profiles of 210Po followed those of 210Pb, lending support to the particle sinking controlled top-down deficits of 210Po. Using an inverse model, the sinking velocity of particles, for the first time in the SCS, was estimated to vary from 3 to 34 m d-1 with the mean value of 15 ± 9 m d-1, indicating that the slow sinking particles largely contribute to the POC flux in the SCS. Beneath the euphotic zone, a consistent descending of the sinking speed implied continuous remineralization of sinking POC in the twilight zone. A preliminary estimate revealed that 1.9-5.4 mmol-C m-2 d-1 remineralized back to carbon dioxide within 100-500 m, representing about 70% of the exported autochthonous POC from the euphotic zone. In 100-1000 m, 2.4-6.6 mmol-C m-2 d-1 (i.e., 84%) remineralized. Thus, the upper twilight zone (i.e., 100-500 m) is the dominant layer of POC remineralization, and POC-induced acidification could be unneglectable there. These results provided insights into the POC-induced acidification mechanism in the mesopelagic water, especially in the upper mesopelagic layer. Article in Journal/Newspaper Ocean acidification Directory of Open Access Journals: DOAJ Articles Frontiers in Marine Science 9 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
ocean acidification biological pump POC export sinking velocity polonium-210 Science Q General. Including nature conservation geographical distribution QH1-199.5 |
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ocean acidification biological pump POC export sinking velocity polonium-210 Science Q General. Including nature conservation geographical distribution QH1-199.5 Weifeng Yang Xiufeng Zhao Minfang Zheng Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea |
topic_facet |
ocean acidification biological pump POC export sinking velocity polonium-210 Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
Coastal acidification has been widely investigated in terms of its rationale and ecological effects in the last decade. However, the driving mechanism for acidification in open seawater, especially in mesopelagic water, is still poorly understood. Here, the sinking velocity and flux attenuation of particulate organic carbon (POC) were examined based upon the radioactive 210Po-210Pb tracer to reveal the remineralization of POC in the mesopelagic zone in the northeastern South China Sea (SCS). Overall, the profiles of 210Po followed those of 210Pb, lending support to the particle sinking controlled top-down deficits of 210Po. Using an inverse model, the sinking velocity of particles, for the first time in the SCS, was estimated to vary from 3 to 34 m d-1 with the mean value of 15 ± 9 m d-1, indicating that the slow sinking particles largely contribute to the POC flux in the SCS. Beneath the euphotic zone, a consistent descending of the sinking speed implied continuous remineralization of sinking POC in the twilight zone. A preliminary estimate revealed that 1.9-5.4 mmol-C m-2 d-1 remineralized back to carbon dioxide within 100-500 m, representing about 70% of the exported autochthonous POC from the euphotic zone. In 100-1000 m, 2.4-6.6 mmol-C m-2 d-1 (i.e., 84%) remineralized. Thus, the upper twilight zone (i.e., 100-500 m) is the dominant layer of POC remineralization, and POC-induced acidification could be unneglectable there. These results provided insights into the POC-induced acidification mechanism in the mesopelagic water, especially in the upper mesopelagic layer. |
format |
Article in Journal/Newspaper |
author |
Weifeng Yang Xiufeng Zhao Minfang Zheng |
author_facet |
Weifeng Yang Xiufeng Zhao Minfang Zheng |
author_sort |
Weifeng Yang |
title |
Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea |
title_short |
Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea |
title_full |
Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea |
title_fullStr |
Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea |
title_full_unstemmed |
Slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the South China Sea |
title_sort |
slow-sinking particulate organic carbon and its attenuation in the mesopelagic water of the south china sea |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/fmars.2022.1018825 https://doaj.org/article/b0a94335a37b4fe3ae158ec5126971bb |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
Frontiers in Marine Science, Vol 9 (2022) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2022.1018825/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.1018825 https://doaj.org/article/b0a94335a37b4fe3ae158ec5126971bb |
op_doi |
https://doi.org/10.3389/fmars.2022.1018825 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
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1766159065650561024 |