Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer
Polar waters may be highly impacted by ocean acidification (OA) due to increased solubility of CO2 at colder water temperatures. Three experiments examining the influence of OA on primary and bacterial production were conducted during austral summer at Davis Station, East Antarctica (68°35′ S, 77°58...
Published in: | Journal of Experimental Marine Biology and Ecology |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Elsevier Science Bv
2018
|
Subjects: | |
Online Access: | https://eprints.utas.edu.au/30025/ |
id |
ftunivtasmania:oai:eprints.utas.edu.au:30025 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasmania:oai:eprints.utas.edu.au:30025 2023-05-15T13:31:53+02:00 Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer Westwood, KJ Thomson, PG van den Enden, RL Maher, LE Wright, SW Davidson, AT 2018 https://eprints.utas.edu.au/30025/ unknown Elsevier Science Bv Westwood, KJ, Thomson, PG, van den Enden, RL, Maher, LE, Wright, SW and Davidson, AT 2018 , 'Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer' , Journal of Experimental Marine Biology and Ecology, vol. 498 , pp. 46-60 , doi:10.1016/j.jembe.2017.11.003 <http://dx.doi.org/10.1016/j.jembe.2017.11.003>. ocean acidification primary production bacterial production net community production photosynthesis Antarctica Article PeerReviewed 2018 ftunivtasmania https://doi.org/10.1016/j.jembe.2017.11.003 2021-09-13T22:19:30Z Polar waters may be highly impacted by ocean acidification (OA) due to increased solubility of CO2 at colder water temperatures. Three experiments examining the influence of OA on primary and bacterial production were conducted during austral summer at Davis Station, East Antarctica (68°35′ S, 77°58′ E). For each experiment, six minicosm tanks (650 L) were filled with 200 μm filtered coastal seawater containing natural communities of Antarctic marine microbes. Assemblages were incubated for 10 to 12 days at CO2 concentrations ranging from pre-industrial to post-2300. Primary and bacterial production rates were determined using NaH14CO3 and 14C-leucine, respectively. Net community production (NCP) was also determined using dissolved oxygen. In all experiments, maximum photosynthetic rates (Pmax, mg C mg chl a− 1 h− 1) decreased with elevated CO2, clearly reducing rates of total gross primary production (mg C L− 1 h− 1). Rates of cell-specific bacterial productivity (μg C cell− 1 h− 1) also decreased under elevated CO2, yet total bacterial production (μg C L− 1 h− 1) and cell abundances increased with CO2 over Days 0–4. Initial increases in bacterial production and abundance were associated with fewer heterotrophic nanoflagellates and therefore less grazing pressure. The main changes in primary and bacterial productivity generally occurred at CO2 concentrations > 2 × present day (> 780 ppm), with the same responses occurring regardless of seasonally changing environmental conditions and microbial assemblages. However, NCP varied both within and among experiments, largely due to changing nitrate + nitrite (NOx) availability. At NOx concentrations 1.5 μM photosynthesis to respiration ratios showed that populations switched from net autotrophy to heterotrophy and CO2 responses were suppressed. Overall, OA may reduce production in Antarctic coastal wa ters, thereby reducing food availability to higher trophic levels and reducing draw-down of atmospheric CO2, thus forming a positive feedback to climate change. NOX limitation may suppress this OA response but cause a similar decline. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ocean acidification University of Tasmania: UTas ePrints Antarctic East Antarctica Austral Davis Station ENVELOPE(77.968,77.968,-68.576,-68.576) Davis-Station ENVELOPE(77.968,77.968,-68.576,-68.576) Journal of Experimental Marine Biology and Ecology 498 46 60 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
unknown |
topic |
ocean acidification primary production bacterial production net community production photosynthesis Antarctica |
spellingShingle |
ocean acidification primary production bacterial production net community production photosynthesis Antarctica Westwood, KJ Thomson, PG van den Enden, RL Maher, LE Wright, SW Davidson, AT Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer |
topic_facet |
ocean acidification primary production bacterial production net community production photosynthesis Antarctica |
description |
Polar waters may be highly impacted by ocean acidification (OA) due to increased solubility of CO2 at colder water temperatures. Three experiments examining the influence of OA on primary and bacterial production were conducted during austral summer at Davis Station, East Antarctica (68°35′ S, 77°58′ E). For each experiment, six minicosm tanks (650 L) were filled with 200 μm filtered coastal seawater containing natural communities of Antarctic marine microbes. Assemblages were incubated for 10 to 12 days at CO2 concentrations ranging from pre-industrial to post-2300. Primary and bacterial production rates were determined using NaH14CO3 and 14C-leucine, respectively. Net community production (NCP) was also determined using dissolved oxygen. In all experiments, maximum photosynthetic rates (Pmax, mg C mg chl a− 1 h− 1) decreased with elevated CO2, clearly reducing rates of total gross primary production (mg C L− 1 h− 1). Rates of cell-specific bacterial productivity (μg C cell− 1 h− 1) also decreased under elevated CO2, yet total bacterial production (μg C L− 1 h− 1) and cell abundances increased with CO2 over Days 0–4. Initial increases in bacterial production and abundance were associated with fewer heterotrophic nanoflagellates and therefore less grazing pressure. The main changes in primary and bacterial productivity generally occurred at CO2 concentrations > 2 × present day (> 780 ppm), with the same responses occurring regardless of seasonally changing environmental conditions and microbial assemblages. However, NCP varied both within and among experiments, largely due to changing nitrate + nitrite (NOx) availability. At NOx concentrations 1.5 μM photosynthesis to respiration ratios showed that populations switched from net autotrophy to heterotrophy and CO2 responses were suppressed. Overall, OA may reduce production in Antarctic coastal wa ters, thereby reducing food availability to higher trophic levels and reducing draw-down of atmospheric CO2, thus forming a positive feedback to climate change. NOX limitation may suppress this OA response but cause a similar decline. |
format |
Article in Journal/Newspaper |
author |
Westwood, KJ Thomson, PG van den Enden, RL Maher, LE Wright, SW Davidson, AT |
author_facet |
Westwood, KJ Thomson, PG van den Enden, RL Maher, LE Wright, SW Davidson, AT |
author_sort |
Westwood, KJ |
title |
Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer |
title_short |
Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer |
title_full |
Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer |
title_fullStr |
Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer |
title_full_unstemmed |
Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer |
title_sort |
ocean acidification impacts primary and bacterial production in antarctic coastal waters during austral summer |
publisher |
Elsevier Science Bv |
publishDate |
2018 |
url |
https://eprints.utas.edu.au/30025/ |
long_lat |
ENVELOPE(77.968,77.968,-68.576,-68.576) ENVELOPE(77.968,77.968,-68.576,-68.576) |
geographic |
Antarctic East Antarctica Austral Davis Station Davis-Station |
geographic_facet |
Antarctic East Antarctica Austral Davis Station Davis-Station |
genre |
Antarc* Antarctic Antarctica East Antarctica Ocean acidification |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ocean acidification |
op_relation |
Westwood, KJ, Thomson, PG, van den Enden, RL, Maher, LE, Wright, SW and Davidson, AT 2018 , 'Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer' , Journal of Experimental Marine Biology and Ecology, vol. 498 , pp. 46-60 , doi:10.1016/j.jembe.2017.11.003 <http://dx.doi.org/10.1016/j.jembe.2017.11.003>. |
op_doi |
https://doi.org/10.1016/j.jembe.2017.11.003 |
container_title |
Journal of Experimental Marine Biology and Ecology |
container_volume |
498 |
container_start_page |
46 |
op_container_end_page |
60 |
_version_ |
1766021908382351360 |