Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms
Since 2003, concentrations of dissolved organic carbon (DOC) in lakes in the Kangerlussuaq region declined by 14–55 percent, with these decreasing DOC concentrations potentially altering lake ecology and reflecting changes in regional carbon (C) cycling. To evaluate possible mechanisms responsible f...
Published in: | Arctic, Antarctic, and Alpine Research |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Taylor & Francis Group
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1080/15230430.2018.1436815 https://doaj.org/article/152c8537fa0649688ab222f9f53e71ca |
id |
ftdoajarticles:oai:doaj.org/article:152c8537fa0649688ab222f9f53e71ca |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:152c8537fa0649688ab222f9f53e71ca 2023-05-15T14:14:29+02:00 Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms Rachel A. Fowler Jasmine E. Saros Christopher L. Osburn 2018-01-01T00:00:00Z https://doi.org/10.1080/15230430.2018.1436815 https://doaj.org/article/152c8537fa0649688ab222f9f53e71ca EN eng Taylor & Francis Group http://dx.doi.org/10.1080/15230430.2018.1436815 https://doaj.org/toc/1523-0430 https://doaj.org/toc/1938-4246 1523-0430 1938-4246 doi:10.1080/15230430.2018.1436815 https://doaj.org/article/152c8537fa0649688ab222f9f53e71ca Arctic, Antarctic, and Alpine Research, Vol 50, Iss 1 (2018) dissolved organic carbon dust bacterial processing photoreactivity lake c cycling Environmental sciences GE1-350 Ecology QH540-549.5 article 2018 ftdoajarticles https://doi.org/10.1080/15230430.2018.1436815 2022-12-31T09:47:16Z Since 2003, concentrations of dissolved organic carbon (DOC) in lakes in the Kangerlussuaq region declined by 14–55 percent, with these decreasing DOC concentrations potentially altering lake ecology and reflecting changes in regional carbon (C) cycling. To evaluate possible mechanisms responsible for this shift, we performed experiments to test the effects of dust addition, bacterial activity, or photodegradation on DOC concentration and two DOC quality metrics: the specific ultraviolet absorbance (SUVA254) and the chromophoric DOC spectral slope coefficient (S275–295). Lake-water DOC concentrations did not decline in any treatments, but there were changes in DOC quality. Dust addition increased SUVA254 and decreased the magnitude of S275–295 in one lake, the impacts of bacterial activity were variable, and sunlight exposure elicited a decline in SUVA254 and an increase in the magnitude of S275–295 in all lakes. These results suggest that DOC pools in the study lakes are photoreactive, even though the lakes are characterized by long residence times, but that declining DOC concentration did not result from this mechanism. While the tested mechanisms did not explain the decline in DOC concentration observed in recent years, they did yield new information about how dust, bacterial activity, or light can influence DOC quality in the lakes of the Kangerlussuaq region. Article in Journal/Newspaper Antarctic and Alpine Research Arctic Kangerlussuaq Directory of Open Access Journals: DOAJ Articles Kangerlussuaq ENVELOPE(-55.633,-55.633,72.633,72.633) Arctic, Antarctic, and Alpine Research 50 1 S100013 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
dissolved organic carbon dust bacterial processing photoreactivity lake c cycling Environmental sciences GE1-350 Ecology QH540-549.5 |
spellingShingle |
dissolved organic carbon dust bacterial processing photoreactivity lake c cycling Environmental sciences GE1-350 Ecology QH540-549.5 Rachel A. Fowler Jasmine E. Saros Christopher L. Osburn Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms |
topic_facet |
dissolved organic carbon dust bacterial processing photoreactivity lake c cycling Environmental sciences GE1-350 Ecology QH540-549.5 |
description |
Since 2003, concentrations of dissolved organic carbon (DOC) in lakes in the Kangerlussuaq region declined by 14–55 percent, with these decreasing DOC concentrations potentially altering lake ecology and reflecting changes in regional carbon (C) cycling. To evaluate possible mechanisms responsible for this shift, we performed experiments to test the effects of dust addition, bacterial activity, or photodegradation on DOC concentration and two DOC quality metrics: the specific ultraviolet absorbance (SUVA254) and the chromophoric DOC spectral slope coefficient (S275–295). Lake-water DOC concentrations did not decline in any treatments, but there were changes in DOC quality. Dust addition increased SUVA254 and decreased the magnitude of S275–295 in one lake, the impacts of bacterial activity were variable, and sunlight exposure elicited a decline in SUVA254 and an increase in the magnitude of S275–295 in all lakes. These results suggest that DOC pools in the study lakes are photoreactive, even though the lakes are characterized by long residence times, but that declining DOC concentration did not result from this mechanism. While the tested mechanisms did not explain the decline in DOC concentration observed in recent years, they did yield new information about how dust, bacterial activity, or light can influence DOC quality in the lakes of the Kangerlussuaq region. |
format |
Article in Journal/Newspaper |
author |
Rachel A. Fowler Jasmine E. Saros Christopher L. Osburn |
author_facet |
Rachel A. Fowler Jasmine E. Saros Christopher L. Osburn |
author_sort |
Rachel A. Fowler |
title |
Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms |
title_short |
Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms |
title_full |
Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms |
title_fullStr |
Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms |
title_full_unstemmed |
Shifting DOC concentration and quality in the freshwater lakes of the Kangerlussuaq region: An experimental assessment of possible mechanisms |
title_sort |
shifting doc concentration and quality in the freshwater lakes of the kangerlussuaq region: an experimental assessment of possible mechanisms |
publisher |
Taylor & Francis Group |
publishDate |
2018 |
url |
https://doi.org/10.1080/15230430.2018.1436815 https://doaj.org/article/152c8537fa0649688ab222f9f53e71ca |
long_lat |
ENVELOPE(-55.633,-55.633,72.633,72.633) |
geographic |
Kangerlussuaq |
geographic_facet |
Kangerlussuaq |
genre |
Antarctic and Alpine Research Arctic Kangerlussuaq |
genre_facet |
Antarctic and Alpine Research Arctic Kangerlussuaq |
op_source |
Arctic, Antarctic, and Alpine Research, Vol 50, Iss 1 (2018) |
op_relation |
http://dx.doi.org/10.1080/15230430.2018.1436815 https://doaj.org/toc/1523-0430 https://doaj.org/toc/1938-4246 1523-0430 1938-4246 doi:10.1080/15230430.2018.1436815 https://doaj.org/article/152c8537fa0649688ab222f9f53e71ca |
op_doi |
https://doi.org/10.1080/15230430.2018.1436815 |
container_title |
Arctic, Antarctic, and Alpine Research |
container_volume |
50 |
container_issue |
1 |
container_start_page |
S100013 |
_version_ |
1766286921111175168 |