DOM degradation by light and microbes along the Yukon River-coastal ocean continuum
Abstract The Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic war...
Published in: | Scientific Reports |
---|---|
Main Authors: | , , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Springer Science and Business Media LLC
2021
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1038/s41598-021-89327-9 http://www.nature.com/articles/s41598-021-89327-9.pdf http://www.nature.com/articles/s41598-021-89327-9 |
id |
crspringernat:10.1038/s41598-021-89327-9 |
---|---|
record_format |
openpolar |
spelling |
crspringernat:10.1038/s41598-021-89327-9 2023-05-15T14:48:27+02:00 DOM degradation by light and microbes along the Yukon River-coastal ocean continuum Grunert, Brice K. Tzortziou, Maria Neale, Patrick Menendez, Alana Hernes, Peter National Aeronautics and Space Administration 2021 http://dx.doi.org/10.1038/s41598-021-89327-9 http://www.nature.com/articles/s41598-021-89327-9.pdf http://www.nature.com/articles/s41598-021-89327-9 en eng Springer Science and Business Media LLC https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 CC-BY Scientific Reports volume 11, issue 1 ISSN 2045-2322 Multidisciplinary journal-article 2021 crspringernat https://doi.org/10.1038/s41598-021-89327-9 2022-01-14T15:42:54Z Abstract The Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization. Article in Journal/Newspaper Arctic Yukon river Yukon Springer Nature (via Crossref) Arctic Yukon Scientific Reports 11 1 |
institution |
Open Polar |
collection |
Springer Nature (via Crossref) |
op_collection_id |
crspringernat |
language |
English |
topic |
Multidisciplinary |
spellingShingle |
Multidisciplinary Grunert, Brice K. Tzortziou, Maria Neale, Patrick Menendez, Alana Hernes, Peter DOM degradation by light and microbes along the Yukon River-coastal ocean continuum |
topic_facet |
Multidisciplinary |
description |
Abstract The Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization. |
author2 |
National Aeronautics and Space Administration |
format |
Article in Journal/Newspaper |
author |
Grunert, Brice K. Tzortziou, Maria Neale, Patrick Menendez, Alana Hernes, Peter |
author_facet |
Grunert, Brice K. Tzortziou, Maria Neale, Patrick Menendez, Alana Hernes, Peter |
author_sort |
Grunert, Brice K. |
title |
DOM degradation by light and microbes along the Yukon River-coastal ocean continuum |
title_short |
DOM degradation by light and microbes along the Yukon River-coastal ocean continuum |
title_full |
DOM degradation by light and microbes along the Yukon River-coastal ocean continuum |
title_fullStr |
DOM degradation by light and microbes along the Yukon River-coastal ocean continuum |
title_full_unstemmed |
DOM degradation by light and microbes along the Yukon River-coastal ocean continuum |
title_sort |
dom degradation by light and microbes along the yukon river-coastal ocean continuum |
publisher |
Springer Science and Business Media LLC |
publishDate |
2021 |
url |
http://dx.doi.org/10.1038/s41598-021-89327-9 http://www.nature.com/articles/s41598-021-89327-9.pdf http://www.nature.com/articles/s41598-021-89327-9 |
geographic |
Arctic Yukon |
geographic_facet |
Arctic Yukon |
genre |
Arctic Yukon river Yukon |
genre_facet |
Arctic Yukon river Yukon |
op_source |
Scientific Reports volume 11, issue 1 ISSN 2045-2322 |
op_rights |
https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1038/s41598-021-89327-9 |
container_title |
Scientific Reports |
container_volume |
11 |
container_issue |
1 |
_version_ |
1766319537836261376 |