Ocean acidification changes the structure of an Antarctic coastal protistan community
Antarctic near-shore waters are amongst the most sensitive in the world to ocean acidification. Microbes occupying these waters are critical drivers of ecosystem productivity, elemental cycling and ocean biogeochemistry, yet little is known about their sensitivity to ocean acidification. A six-level...
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ftcopernicus:oai:publications.copernicus.org:bg59481 2023-05-15T13:35:06+02:00 Ocean acidification changes the structure of an Antarctic coastal protistan community Hancock, Alyce M. Davidson, Andrew T. McKinlay, John McMinn, Andrew Schulz, Kai G. Enden, Rick L. 2019-01-28 application/pdf https://doi.org/10.5194/bg-15-2393-2018 https://www.biogeosciences.net/15/2393/2018/ eng eng doi:10.5194/bg-15-2393-2018 https://www.biogeosciences.net/15/2393/2018/ eISSN: 1726-4189 Text 2019 ftcopernicus https://doi.org/10.5194/bg-15-2393-2018 2019-12-24T09:50:28Z Antarctic near-shore waters are amongst the most sensitive in the world to ocean acidification. Microbes occupying these waters are critical drivers of ecosystem productivity, elemental cycling and ocean biogeochemistry, yet little is known about their sensitivity to ocean acidification. A six-level, dose–response experiment was conducted using 650 L incubation tanks (minicosms) adjusted to a gradient in fugacity of carbon dioxide ( f CO 2 ) from 343 to 1641 µatm . The six minicosms were filled with near-shore water from Prydz Bay, East Antarctica, and the protistan composition and abundance was determined by microscopy during 18 days of incubation. No CO 2 -related change in the protistan community composition was observed during the initial 8 day acclimation period under low light. Thereafter, the response of both autotrophic and heterotrophic protists to f CO 2 was species-specific. The response of diatoms was mainly cell size related; microplanktonic diatoms ( > 20 µm ) increased in abundance with low to moderate f CO 2 (343–634 µatm ) but decreased at f CO 2 ≥ 953 µatm . Similarly, the abundance of Phaeocystis antarctica increased with increasing f CO 2 peaking at 634 µatm . Above this threshold the abundance of micro-sized diatoms and P. antarctica fell dramatically, and nanoplanktonic diatoms ( ≤ 20 µm ) dominated, therefore culminating in a significant change in the protistan community composition. Comparisons of these results with previous experiments conducted at this site show that the f CO 2 thresholds are similar, despite seasonal and interannual differences in the physical and biotic environment. This suggests that near-shore microbial communities are likely to change significantly near the end of this century if anthropogenic CO 2 release continues unabated, with profound ramifications for near-shore Antarctic ecosystem food webs and biogeochemical cycling. Text Antarc* Antarctic Antarctica East Antarctica Ocean acidification Prydz Bay Copernicus Publications: E-Journals Antarctic East Antarctica Prydz Bay Biogeosciences 15 8 2393 2410 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Antarctic near-shore waters are amongst the most sensitive in the world to ocean acidification. Microbes occupying these waters are critical drivers of ecosystem productivity, elemental cycling and ocean biogeochemistry, yet little is known about their sensitivity to ocean acidification. A six-level, dose–response experiment was conducted using 650 L incubation tanks (minicosms) adjusted to a gradient in fugacity of carbon dioxide ( f CO 2 ) from 343 to 1641 µatm . The six minicosms were filled with near-shore water from Prydz Bay, East Antarctica, and the protistan composition and abundance was determined by microscopy during 18 days of incubation. No CO 2 -related change in the protistan community composition was observed during the initial 8 day acclimation period under low light. Thereafter, the response of both autotrophic and heterotrophic protists to f CO 2 was species-specific. The response of diatoms was mainly cell size related; microplanktonic diatoms ( > 20 µm ) increased in abundance with low to moderate f CO 2 (343–634 µatm ) but decreased at f CO 2 ≥ 953 µatm . Similarly, the abundance of Phaeocystis antarctica increased with increasing f CO 2 peaking at 634 µatm . Above this threshold the abundance of micro-sized diatoms and P. antarctica fell dramatically, and nanoplanktonic diatoms ( ≤ 20 µm ) dominated, therefore culminating in a significant change in the protistan community composition. Comparisons of these results with previous experiments conducted at this site show that the f CO 2 thresholds are similar, despite seasonal and interannual differences in the physical and biotic environment. This suggests that near-shore microbial communities are likely to change significantly near the end of this century if anthropogenic CO 2 release continues unabated, with profound ramifications for near-shore Antarctic ecosystem food webs and biogeochemical cycling. |
format |
Text |
author |
Hancock, Alyce M. Davidson, Andrew T. McKinlay, John McMinn, Andrew Schulz, Kai G. Enden, Rick L. |
spellingShingle |
Hancock, Alyce M. Davidson, Andrew T. McKinlay, John McMinn, Andrew Schulz, Kai G. Enden, Rick L. Ocean acidification changes the structure of an Antarctic coastal protistan community |
author_facet |
Hancock, Alyce M. Davidson, Andrew T. McKinlay, John McMinn, Andrew Schulz, Kai G. Enden, Rick L. |
author_sort |
Hancock, Alyce M. |
title |
Ocean acidification changes the structure of an Antarctic coastal protistan community |
title_short |
Ocean acidification changes the structure of an Antarctic coastal protistan community |
title_full |
Ocean acidification changes the structure of an Antarctic coastal protistan community |
title_fullStr |
Ocean acidification changes the structure of an Antarctic coastal protistan community |
title_full_unstemmed |
Ocean acidification changes the structure of an Antarctic coastal protistan community |
title_sort |
ocean acidification changes the structure of an antarctic coastal protistan community |
publishDate |
2019 |
url |
https://doi.org/10.5194/bg-15-2393-2018 https://www.biogeosciences.net/15/2393/2018/ |
geographic |
Antarctic East Antarctica Prydz Bay |
geographic_facet |
Antarctic East Antarctica Prydz Bay |
genre |
Antarc* Antarctic Antarctica East Antarctica Ocean acidification Prydz Bay |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ocean acidification Prydz Bay |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-15-2393-2018 https://www.biogeosciences.net/15/2393/2018/ |
op_doi |
https://doi.org/10.5194/bg-15-2393-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
8 |
container_start_page |
2393 |
op_container_end_page |
2410 |
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1766061008576577536 |