Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean
Changes in oceanic circulation and physiochemical parameters due to climate change may alter the distribution, structure and function of marine microbial communities, thereby altering the action of the biological carbon pump. One area of current and predicted future change is the sub-Antarctic zone...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Online Access: | https://doi.org/10.1016/j.dsr2.2011.05.019 http://ecite.utas.edu.au/76809 |
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ftunivtasecite:oai:ecite.utas.edu.au:76809 2023-05-15T14:02:30+02:00 Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean Evans, C Thomson, PG Davidson, A Bowie, AR van den Enden, R Witte, H Brussaard, CPD 2011 application/pdf https://doi.org/10.1016/j.dsr2.2011.05.019 http://ecite.utas.edu.au/76809 en eng Pergamon-Elsevier Science Ltd http://ecite.utas.edu.au/76809/1/Evans_2011_Deep-Sea-Research-Part-II-Topical-Studies-in-Oceanography.pdf http://dx.doi.org/10.1016/j.dsr2.2011.05.019 Evans, C and Thomson, PG and Davidson, A and Bowie, AR and van den Enden, R and Witte, H and Brussaard, CPD, Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean, Deep-Sea Research. Part 2: Topical Studies in Oceanography, 58, (21-22) pp. 2150-2161. ISSN 0967-0645 (2011) [Refereed Article] http://ecite.utas.edu.au/76809 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2011 ftunivtasecite https://doi.org/10.1016/j.dsr2.2011.05.019 2019-12-13T21:43:03Z Changes in oceanic circulation and physiochemical parameters due to climate change may alter the distribution, structure and function of marine microbial communities, thereby altering the action of the biological carbon pump. One area of current and predicted future change is the sub-Antarctic zone (SAZ) to the southeast of Tasmania, Australia, where a southward shift in westerly winds appears to be forcing warmer and macronutrient-poor subtropical waters into the sub-Antarctic zone (SAZ). We investigated the impact of these subtropical waters on the microbial community of the SAZ on the SAZ-Sense cruise during the austral summer of 2007. The abundance of pico- and nanoeukaryotic algae, cyanobacteria, heterotrophic nanoflagellates, bacteria and viruses was determined by flow cytometry at stations in the Polar Frontal Zone (PFZ), the SAZ and in Subtropical Zone (STZ). Using cluster and similarity profile analyses on integrated microbial abundances over the top 200 m, we found that microbial communities located in the potential future SAZ to the southeast of Tasmania formed two distinct groups from those of the remainder of the SAZ and the PFZ. In the waters of the potential future SAZ, shallow mixed layers and increased iron concentrations elevated cyanobacterial, bacterial and viral abundances and increased percentage high DNA bacteria, resulting in communities similar to those of subtropical waters. Conversely, waters of the PFZ exhibited relatively low concentrations of autotrophic and heterotrophic microbes and viruses, indicative of the iron limitation in this region. A Distance Based Linear Model determined that salinity and nitrogen availability (nitrate, nitrite and ammonia concentrations) were the most influential environmental parameters over the survey, explaining 72% of the variation in microbial community structure. The microbial community of the potential future SAZ showed a shift away from particulate carbon export from the photic zone towards increased production by smaller cells, increased significance of the microbial loop and viral lysis. These changes would promote carbon recycling within the photic zone, thereby potentially decreasing the capacity of the future SAZ to absorb CO2. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean eCite UTAS (University of Tasmania) Antarctic Austral Southern Ocean Deep Sea Research Part II: Topical Studies in Oceanography 58 21-22 2150 2161 |
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Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical Oceanography Evans, C Thomson, PG Davidson, A Bowie, AR van den Enden, R Witte, H Brussaard, CPD Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
Changes in oceanic circulation and physiochemical parameters due to climate change may alter the distribution, structure and function of marine microbial communities, thereby altering the action of the biological carbon pump. One area of current and predicted future change is the sub-Antarctic zone (SAZ) to the southeast of Tasmania, Australia, where a southward shift in westerly winds appears to be forcing warmer and macronutrient-poor subtropical waters into the sub-Antarctic zone (SAZ). We investigated the impact of these subtropical waters on the microbial community of the SAZ on the SAZ-Sense cruise during the austral summer of 2007. The abundance of pico- and nanoeukaryotic algae, cyanobacteria, heterotrophic nanoflagellates, bacteria and viruses was determined by flow cytometry at stations in the Polar Frontal Zone (PFZ), the SAZ and in Subtropical Zone (STZ). Using cluster and similarity profile analyses on integrated microbial abundances over the top 200 m, we found that microbial communities located in the potential future SAZ to the southeast of Tasmania formed two distinct groups from those of the remainder of the SAZ and the PFZ. In the waters of the potential future SAZ, shallow mixed layers and increased iron concentrations elevated cyanobacterial, bacterial and viral abundances and increased percentage high DNA bacteria, resulting in communities similar to those of subtropical waters. Conversely, waters of the PFZ exhibited relatively low concentrations of autotrophic and heterotrophic microbes and viruses, indicative of the iron limitation in this region. A Distance Based Linear Model determined that salinity and nitrogen availability (nitrate, nitrite and ammonia concentrations) were the most influential environmental parameters over the survey, explaining 72% of the variation in microbial community structure. The microbial community of the potential future SAZ showed a shift away from particulate carbon export from the photic zone towards increased production by smaller cells, increased significance of the microbial loop and viral lysis. These changes would promote carbon recycling within the photic zone, thereby potentially decreasing the capacity of the future SAZ to absorb CO2. |
format |
Article in Journal/Newspaper |
author |
Evans, C Thomson, PG Davidson, A Bowie, AR van den Enden, R Witte, H Brussaard, CPD |
author_facet |
Evans, C Thomson, PG Davidson, A Bowie, AR van den Enden, R Witte, H Brussaard, CPD |
author_sort |
Evans, C |
title |
Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean |
title_short |
Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean |
title_full |
Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean |
title_fullStr |
Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean |
title_full_unstemmed |
Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean |
title_sort |
potential climate change impacts on microbial distribution and carbon cycling in the australian southern ocean |
publisher |
Pergamon-Elsevier Science Ltd |
publishDate |
2011 |
url |
https://doi.org/10.1016/j.dsr2.2011.05.019 http://ecite.utas.edu.au/76809 |
geographic |
Antarctic Austral Southern Ocean |
geographic_facet |
Antarctic Austral Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
http://ecite.utas.edu.au/76809/1/Evans_2011_Deep-Sea-Research-Part-II-Topical-Studies-in-Oceanography.pdf http://dx.doi.org/10.1016/j.dsr2.2011.05.019 Evans, C and Thomson, PG and Davidson, A and Bowie, AR and van den Enden, R and Witte, H and Brussaard, CPD, Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean, Deep-Sea Research. Part 2: Topical Studies in Oceanography, 58, (21-22) pp. 2150-2161. ISSN 0967-0645 (2011) [Refereed Article] http://ecite.utas.edu.au/76809 |
op_doi |
https://doi.org/10.1016/j.dsr2.2011.05.019 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
58 |
container_issue |
21-22 |
container_start_page |
2150 |
op_container_end_page |
2161 |
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