Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions
The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO 2 ), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupl...
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ftcopernicus:oai:publications.copernicus.org:bg49981 2023-05-15T17:50:56+02:00 Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions Hornick, Thomas Bach, Lennart T. Crawfurd, Katharine J. Spilling, Kristian Achterberg, Eric P. Woodhouse, Jason N. Schulz, Kai G. Brussaard, Corina P. D. Riebesell, Ulf Grossart, Hans-Peter 2018-09-27 application/pdf https://doi.org/10.5194/bg-14-1-2017 https://www.biogeosciences.net/14/1/2017/ eng eng doi:10.5194/bg-14-1-2017 https://www.biogeosciences.net/14/1/2017/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-14-1-2017 2019-12-24T09:51:46Z The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO 2 ), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupling of heterotrophic bacteria to phytoplankton when nutrients are limited. Previous experiments were, for the most part, undertaken during productive phases or following nutrient additions designed to stimulate algal blooms. Therefore, we performed an in situ large-volume mesocosm ( ∼ 55 m 3 ) experiment in the Baltic Sea by simulating different fugacities of CO 2 ( f CO 2 ) extending from present to future conditions. The study was conducted in July–August after the nominal spring bloom, in order to maintain low-nutrient conditions throughout the experiment. This resulted in phytoplankton communities dominated by small-sized functional groups (picophytoplankton). There was no consistent f CO 2 -induced effect on bacterial protein production (BPP), cell-specific BPP (csBPP) or biovolumes (BVs) of either free-living (FL) or particle-associated (PA) heterotrophic bacteria, when considered as individual components (univariate analyses). Permutational Multivariate Analysis of Variance (PERMANOVA) revealed a significant effect of the f CO 2 treatment on entire assemblages of dissolved and particulate nutrients, metabolic parameters and the bacteria–phytoplankton community. However, distance-based linear modelling only identified f CO 2 as a factor explaining the variability observed amongst the microbial community composition, but not for explaining variability within the metabolic parameters. This suggests that f CO 2 impacts on microbial metabolic parameters occurred indirectly through varying physicochemical parameters and microbial species composition. Cluster analyses examining the co-occurrence of different functional groups of bacteria and phytoplankton further revealed a separation of the four f CO 2 -treated mesocosms from both control mesocosms, indicating that complex trophic interactions might be altered in a future acidified ocean. Possible consequences for nutrient cycling and carbon export are still largely unknown, in particular in a nutrient-limited ocean. Text Ocean acidification Copernicus Publications: E-Journals Biogeosciences 14 1 1 15 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
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The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO 2 ), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupling of heterotrophic bacteria to phytoplankton when nutrients are limited. Previous experiments were, for the most part, undertaken during productive phases or following nutrient additions designed to stimulate algal blooms. Therefore, we performed an in situ large-volume mesocosm ( ∼ 55 m 3 ) experiment in the Baltic Sea by simulating different fugacities of CO 2 ( f CO 2 ) extending from present to future conditions. The study was conducted in July–August after the nominal spring bloom, in order to maintain low-nutrient conditions throughout the experiment. This resulted in phytoplankton communities dominated by small-sized functional groups (picophytoplankton). There was no consistent f CO 2 -induced effect on bacterial protein production (BPP), cell-specific BPP (csBPP) or biovolumes (BVs) of either free-living (FL) or particle-associated (PA) heterotrophic bacteria, when considered as individual components (univariate analyses). Permutational Multivariate Analysis of Variance (PERMANOVA) revealed a significant effect of the f CO 2 treatment on entire assemblages of dissolved and particulate nutrients, metabolic parameters and the bacteria–phytoplankton community. However, distance-based linear modelling only identified f CO 2 as a factor explaining the variability observed amongst the microbial community composition, but not for explaining variability within the metabolic parameters. This suggests that f CO 2 impacts on microbial metabolic parameters occurred indirectly through varying physicochemical parameters and microbial species composition. Cluster analyses examining the co-occurrence of different functional groups of bacteria and phytoplankton further revealed a separation of the four f CO 2 -treated mesocosms from both control mesocosms, indicating that complex trophic interactions might be altered in a future acidified ocean. Possible consequences for nutrient cycling and carbon export are still largely unknown, in particular in a nutrient-limited ocean. |
format |
Text |
author |
Hornick, Thomas Bach, Lennart T. Crawfurd, Katharine J. Spilling, Kristian Achterberg, Eric P. Woodhouse, Jason N. Schulz, Kai G. Brussaard, Corina P. D. Riebesell, Ulf Grossart, Hans-Peter |
spellingShingle |
Hornick, Thomas Bach, Lennart T. Crawfurd, Katharine J. Spilling, Kristian Achterberg, Eric P. Woodhouse, Jason N. Schulz, Kai G. Brussaard, Corina P. D. Riebesell, Ulf Grossart, Hans-Peter Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
author_facet |
Hornick, Thomas Bach, Lennart T. Crawfurd, Katharine J. Spilling, Kristian Achterberg, Eric P. Woodhouse, Jason N. Schulz, Kai G. Brussaard, Corina P. D. Riebesell, Ulf Grossart, Hans-Peter |
author_sort |
Hornick, Thomas |
title |
Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
title_short |
Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
title_full |
Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
title_fullStr |
Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
title_full_unstemmed |
Ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
title_sort |
ocean acidification impacts bacteria–phytoplankton coupling at low-nutrient conditions |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-14-1-2017 https://www.biogeosciences.net/14/1/2017/ |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-14-1-2017 https://www.biogeosciences.net/14/1/2017/ |
op_doi |
https://doi.org/10.5194/bg-14-1-2017 |
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Biogeosciences |
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14 |
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15 |
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1766157887336349696 |