Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica
Abstract Antarctic seas, and particularly the Amundsen Sea Polynya, are some of the most productive oceanic regions on Earth. Ice-algal production during austral spring is followed by open-water pelagic production later in the season. Although ice-free growth accounts for a greater percentage of the...
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University of California Press
2015
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crunicaliforniap:10.12952/journal.elementa.000060 2023-11-12T04:00:47+01:00 Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica Sipler, Rachel E. Connelly, Tara L. Deming, Jody W. Tremblay, Jean-Éric 2015 http://dx.doi.org/10.12952/journal.elementa.000060 http://online.ucpress.edu/elementa/article-pdf/doi/10.12952/journal.elementa.000060/467711/67-675-1-ce.pdf en eng University of California Press Elementa: Science of the Anthropocene volume 3 ISSN 2325-1026 Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography journal-article 2015 crunicaliforniap https://doi.org/10.12952/journal.elementa.000060 2023-10-15T17:45:00Z Abstract Antarctic seas, and particularly the Amundsen Sea Polynya, are some of the most productive oceanic regions on Earth. Ice-algal production during austral spring is followed by open-water pelagic production later in the season. Although ice-free growth accounts for a greater percentage of the annual net primary production, ice algae provide an important source of nutrients to organisms throughout the water column and benthos in areas and seasons when open-water production is insignificant. The objectives of this study were to assess the bioavailability of dissolved organic matter (DOM), sourced from ice algae or the chlorophyll maximum (chl max), to marine bacterioplankton and to determine the fate of carbon within these different DOM pools, including loss to respiration, incorporation into bacterial biomass and retention within the DOM pool itself. Nutrient concentrations and bacterial abundance, production, and cell volume were monitored during a 7-day bioassay study involving four treatments conducted shipboard in the Amundsen Sea Polynya, Antarctica. The greatest response in bacterial abundance and activity was observed when ice-algal meltwater was supplied to aphotic zone bacterioplankton collected from 170-m depth. However, bacterial growth efficiency was higher (24%) when chl max water was supplied to the same aphotic zone bacterial community compared to the bacterial growth efficiency of the ice-algal treatment (15%). Approximately 15% of dissolved organic carbon (DOC) from the ice-algal source and 18% from the chl max was consumed by aphotic bacterial communities over the relatively short, one-week incubation. In contrast, 65% of the dissolved organic nitrogen (DON) added as an integral part of the ice-algal DOM was consumed, but none of the DON supplied with chl max water was labile. This study underscores the importance of considering DOM sources when investigating or predicting changes in carbon and nitrogen cycling within the Amundsen Sea. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica ice algae University of California Press (via Crossref) Antarctic Austral Amundsen Sea Elementa: Science of the Anthropocene 3 |
institution |
Open Polar |
collection |
University of California Press (via Crossref) |
op_collection_id |
crunicaliforniap |
language |
English |
topic |
Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography |
spellingShingle |
Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography Sipler, Rachel E. Connelly, Tara L. Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica |
topic_facet |
Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography |
description |
Abstract Antarctic seas, and particularly the Amundsen Sea Polynya, are some of the most productive oceanic regions on Earth. Ice-algal production during austral spring is followed by open-water pelagic production later in the season. Although ice-free growth accounts for a greater percentage of the annual net primary production, ice algae provide an important source of nutrients to organisms throughout the water column and benthos in areas and seasons when open-water production is insignificant. The objectives of this study were to assess the bioavailability of dissolved organic matter (DOM), sourced from ice algae or the chlorophyll maximum (chl max), to marine bacterioplankton and to determine the fate of carbon within these different DOM pools, including loss to respiration, incorporation into bacterial biomass and retention within the DOM pool itself. Nutrient concentrations and bacterial abundance, production, and cell volume were monitored during a 7-day bioassay study involving four treatments conducted shipboard in the Amundsen Sea Polynya, Antarctica. The greatest response in bacterial abundance and activity was observed when ice-algal meltwater was supplied to aphotic zone bacterioplankton collected from 170-m depth. However, bacterial growth efficiency was higher (24%) when chl max water was supplied to the same aphotic zone bacterial community compared to the bacterial growth efficiency of the ice-algal treatment (15%). Approximately 15% of dissolved organic carbon (DOC) from the ice-algal source and 18% from the chl max was consumed by aphotic bacterial communities over the relatively short, one-week incubation. In contrast, 65% of the dissolved organic nitrogen (DON) added as an integral part of the ice-algal DOM was consumed, but none of the DON supplied with chl max water was labile. This study underscores the importance of considering DOM sources when investigating or predicting changes in carbon and nitrogen cycling within the Amundsen Sea. |
author2 |
Deming, Jody W. Tremblay, Jean-Éric |
format |
Article in Journal/Newspaper |
author |
Sipler, Rachel E. Connelly, Tara L. |
author_facet |
Sipler, Rachel E. Connelly, Tara L. |
author_sort |
Sipler, Rachel E. |
title |
Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica |
title_short |
Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica |
title_full |
Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica |
title_fullStr |
Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica |
title_full_unstemmed |
Bioavailability of surface dissolved organic matter to aphotic bacterial communities in the Amundsen Sea Polynya, Antarctica |
title_sort |
bioavailability of surface dissolved organic matter to aphotic bacterial communities in the amundsen sea polynya, antarctica |
publisher |
University of California Press |
publishDate |
2015 |
url |
http://dx.doi.org/10.12952/journal.elementa.000060 http://online.ucpress.edu/elementa/article-pdf/doi/10.12952/journal.elementa.000060/467711/67-675-1-ce.pdf |
geographic |
Antarctic Austral Amundsen Sea |
geographic_facet |
Antarctic Austral Amundsen Sea |
genre |
Amundsen Sea Antarc* Antarctic Antarctica ice algae |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica ice algae |
op_source |
Elementa: Science of the Anthropocene volume 3 ISSN 2325-1026 |
op_doi |
https://doi.org/10.12952/journal.elementa.000060 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
3 |
_version_ |
1782328775335215104 |