Cargando…

Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica

Perennially ice-covered lakes that host benthic microbial ecosystems are present in many regions of Antarctica. Lake Untersee is an ultra-oligotrophic lake that is substantially different from any other lakes on the continent as it does not develop a seasonal moat and therefore shares similarities t...

Descripción completa

Detalles Bibliográficos
Autores principales: Marsh, Nicole B., Lacelle, Denis, Faucher, Benoit, Cotroneo, Sarina, Jasperse, Liam, Clark, Ian D., Andersen, Dale T.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7378197/
https://www.ncbi.nlm.nih.gov/pubmed/32704043
http://dx.doi.org/10.1038/s41598-020-69116-6
_version_ 1783562363190902784
author Marsh, Nicole B.
Lacelle, Denis
Faucher, Benoit
Cotroneo, Sarina
Jasperse, Liam
Clark, Ian D.
Andersen, Dale T.
author_facet Marsh, Nicole B.
Lacelle, Denis
Faucher, Benoit
Cotroneo, Sarina
Jasperse, Liam
Clark, Ian D.
Andersen, Dale T.
author_sort Marsh, Nicole B.
collection PubMed
description Perennially ice-covered lakes that host benthic microbial ecosystems are present in many regions of Antarctica. Lake Untersee is an ultra-oligotrophic lake that is substantially different from any other lakes on the continent as it does not develop a seasonal moat and therefore shares similarities to sub-glacial lakes where they are sealed to the atmosphere. Here, we determine the source of major solutes and carbon to Lake Untersee, evaluate the carbon cycling and assess the metabolic functioning of microbial mats using an isotope geochemistry approach. The findings suggest that the glacial meltwater recharging the closed-basin and well-sealed Lake Untersee largely determines the major solute chemistry of the oxic water column with plagioclase and alumino-silicate weathering contributing < 5% of the Ca(2+)–Na(+) solutes to the lake. The TIC concentration in the lake is very low and is sourced from melting of glacial ice and direct release of occluded CO(2) gases into the water column. The comparison of δ(13)C(TIC) of the oxic lake waters with the δ(13)C in the top microbial mat layer show no fractionation due to non-discriminating photosynthetic fixation of HCO(3)(–) in the high pH and carbon-starved water. The (14)C results indicate that phototrophs are also fixing respired CO(2) from heterotrophic metabolism of the underlying microbial mats layers. The findings provide insights into the development of collaboration in carbon partitioning within the microbial mats to support their growth in a carbon-starved ecosystem.
format Online
Article
Text
id pubmed-7378197
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-73781972020-07-24 Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica Marsh, Nicole B. Lacelle, Denis Faucher, Benoit Cotroneo, Sarina Jasperse, Liam Clark, Ian D. Andersen, Dale T. Sci Rep Article Perennially ice-covered lakes that host benthic microbial ecosystems are present in many regions of Antarctica. Lake Untersee is an ultra-oligotrophic lake that is substantially different from any other lakes on the continent as it does not develop a seasonal moat and therefore shares similarities to sub-glacial lakes where they are sealed to the atmosphere. Here, we determine the source of major solutes and carbon to Lake Untersee, evaluate the carbon cycling and assess the metabolic functioning of microbial mats using an isotope geochemistry approach. The findings suggest that the glacial meltwater recharging the closed-basin and well-sealed Lake Untersee largely determines the major solute chemistry of the oxic water column with plagioclase and alumino-silicate weathering contributing < 5% of the Ca(2+)–Na(+) solutes to the lake. The TIC concentration in the lake is very low and is sourced from melting of glacial ice and direct release of occluded CO(2) gases into the water column. The comparison of δ(13)C(TIC) of the oxic lake waters with the δ(13)C in the top microbial mat layer show no fractionation due to non-discriminating photosynthetic fixation of HCO(3)(–) in the high pH and carbon-starved water. The (14)C results indicate that phototrophs are also fixing respired CO(2) from heterotrophic metabolism of the underlying microbial mats layers. The findings provide insights into the development of collaboration in carbon partitioning within the microbial mats to support their growth in a carbon-starved ecosystem. Nature Publishing Group UK 2020-07-23 /pmc/articles/PMC7378197/ /pubmed/32704043 http://dx.doi.org/10.1038/s41598-020-69116-6 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Marsh, Nicole B.
Lacelle, Denis
Faucher, Benoit
Cotroneo, Sarina
Jasperse, Liam
Clark, Ian D.
Andersen, Dale T.
Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica
title Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica
title_full Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica
title_fullStr Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica
title_full_unstemmed Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica
title_short Sources of solutes and carbon cycling in perennially ice-covered Lake Untersee, Antarctica
title_sort sources of solutes and carbon cycling in perennially ice-covered lake untersee, antarctica
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7378197/
https://www.ncbi.nlm.nih.gov/pubmed/32704043
http://dx.doi.org/10.1038/s41598-020-69116-6
work_keys_str_mv AT marshnicoleb sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica
AT lacelledenis sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica
AT faucherbenoit sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica
AT cotroneosarina sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica
AT jasperseliam sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica
AT clarkiand sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica
AT andersendalet sourcesofsolutesandcarboncyclinginperenniallyicecoveredlakeunterseeantarctica