Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity
High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial c...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-15-209-2018 https://doaj.org/article/51eafdcdfce8491ebf7872e442829b23 |
id |
ftdoajarticles:oai:doaj.org/article:51eafdcdfce8491ebf7872e442829b23 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:51eafdcdfce8491ebf7872e442829b23 2023-05-15T13:49:16+02:00 Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity S. Deppeler K. Petrou K. G. Schulz K. Westwood I. Pearce J. McKinlay A. Davidson 2018-01-01T00:00:00Z https://doi.org/10.5194/bg-15-209-2018 https://doaj.org/article/51eafdcdfce8491ebf7872e442829b23 EN eng Copernicus Publications https://www.biogeosciences.net/15/209/2018/bg-15-209-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-209-2018 1726-4170 1726-4189 https://doaj.org/article/51eafdcdfce8491ebf7872e442829b23 Biogeosciences, Vol 15, Pp 209-231 (2018) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/bg-15-209-2018 2022-12-31T10:42:25Z High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial community in Prydz Bay to CO 2 levels ranging from ambient (343 µatm) to 1641 µatm in six 650 L minicosms. Productivity assays were performed to identify whether a CO 2 threshold existed that led to a change in primary productivity, bacterial productivity, and the accumulation of chlorophyll a (Chl a ) and particulate organic matter (POM) in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to ocean acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO 2 levels ≥ 1140 µatm negatively affected photosynthetic performance and Chl a -normalised primary productivity (csGPP 14 C ), causing significant reductions in gross primary production (GPP 14 C ), Chl a accumulation, nutrient uptake, and POM production. However, there was no effect of CO 2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO 2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs) and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO 2 treatments ≥ 953 µatm (days 3–5), yet gross bacterial production (GBP 14 C ) remained unchanged and cell-specific bacterial productivity (csBP 14 C ) was reduced. Towards the end of the experiment, GBP 14 C and csBP 14 C markedly increased across all treatments regardless of CO 2 availability. This coincided with increased organic matter availability (POC and PON) combined with improved efficiency of carbon uptake. Changes in phytoplankton community production could have negative effects on the Antarctic food web and the biological pump, resulting in ... Article in Journal/Newspaper Antarc* Antarctic Ocean acidification Prydz Bay Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Prydz Bay Biogeosciences 15 1 209 231 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 S. Deppeler K. Petrou K. G. Schulz K. Westwood I. Pearce J. McKinlay A. Davidson Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
High-latitude oceans are anticipated to be some of the first regions affected by ocean acidification. Despite this, the effect of ocean acidification on natural communities of Antarctic marine microbes is still not well understood. In this study we exposed an early spring, coastal marine microbial community in Prydz Bay to CO 2 levels ranging from ambient (343 µatm) to 1641 µatm in six 650 L minicosms. Productivity assays were performed to identify whether a CO 2 threshold existed that led to a change in primary productivity, bacterial productivity, and the accumulation of chlorophyll a (Chl a ) and particulate organic matter (POM) in the minicosms. In addition, photophysiological measurements were performed to identify possible mechanisms driving changes in the phytoplankton community. A critical threshold for tolerance to ocean acidification was identified in the phytoplankton community between 953 and 1140 µatm. CO 2 levels ≥ 1140 µatm negatively affected photosynthetic performance and Chl a -normalised primary productivity (csGPP 14 C ), causing significant reductions in gross primary production (GPP 14 C ), Chl a accumulation, nutrient uptake, and POM production. However, there was no effect of CO 2 on C : N ratios. Over time, the phytoplankton community acclimated to high CO 2 conditions, showing a down-regulation of carbon concentrating mechanisms (CCMs) and likely adjusting other intracellular processes. Bacterial abundance initially increased in CO 2 treatments ≥ 953 µatm (days 3–5), yet gross bacterial production (GBP 14 C ) remained unchanged and cell-specific bacterial productivity (csBP 14 C ) was reduced. Towards the end of the experiment, GBP 14 C and csBP 14 C markedly increased across all treatments regardless of CO 2 availability. This coincided with increased organic matter availability (POC and PON) combined with improved efficiency of carbon uptake. Changes in phytoplankton community production could have negative effects on the Antarctic food web and the biological pump, resulting in ... |
format |
Article in Journal/Newspaper |
author |
S. Deppeler K. Petrou K. G. Schulz K. Westwood I. Pearce J. McKinlay A. Davidson |
author_facet |
S. Deppeler K. Petrou K. G. Schulz K. Westwood I. Pearce J. McKinlay A. Davidson |
author_sort |
S. Deppeler |
title |
Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity |
title_short |
Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity |
title_full |
Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity |
title_fullStr |
Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity |
title_full_unstemmed |
Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO 2 tolerance in phytoplankton productivity |
title_sort |
ocean acidification of a coastal antarctic marine microbial community reveals a critical threshold for co 2 tolerance in phytoplankton productivity |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-15-209-2018 https://doaj.org/article/51eafdcdfce8491ebf7872e442829b23 |
geographic |
Antarctic The Antarctic Prydz Bay |
geographic_facet |
Antarctic The Antarctic Prydz Bay |
genre |
Antarc* Antarctic Ocean acidification Prydz Bay |
genre_facet |
Antarc* Antarctic Ocean acidification Prydz Bay |
op_source |
Biogeosciences, Vol 15, Pp 209-231 (2018) |
op_relation |
https://www.biogeosciences.net/15/209/2018/bg-15-209-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-209-2018 1726-4170 1726-4189 https://doaj.org/article/51eafdcdfce8491ebf7872e442829b23 |
op_doi |
https://doi.org/10.5194/bg-15-209-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
1 |
container_start_page |
209 |
op_container_end_page |
231 |
_version_ |
1766251071740575744 |