Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment
The Southern Ocean provides a vital service by absorbing about one-sixth of humankind's annual emissions of CO 2 . This comes with a cost – an increase in ocean acidity that is expected to have negative impacts on ocean ecosystems. The reduced ability of phytoplankton and zooplankton to precipi...
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ftdoajarticles:oai:doaj.org/article:a80fcd51389046188bc11e4db5c34097 2023-05-15T14:03:12+02:00 Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment T. W. Trull A. Passmore D. M. Davies T. Smit K. Berry B. Tilbrook 2018-01-01T00:00:00Z https://doi.org/10.5194/bg-15-31-2018 https://doaj.org/article/a80fcd51389046188bc11e4db5c34097 EN eng Copernicus Publications https://www.biogeosciences.net/15/31/2018/bg-15-31-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-31-2018 1726-4170 1726-4189 https://doaj.org/article/a80fcd51389046188bc11e4db5c34097 Biogeosciences, Vol 15, Pp 31-49 (2018) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/bg-15-31-2018 2022-12-31T02:40:26Z The Southern Ocean provides a vital service by absorbing about one-sixth of humankind's annual emissions of CO 2 . This comes with a cost – an increase in ocean acidity that is expected to have negative impacts on ocean ecosystems. The reduced ability of phytoplankton and zooplankton to precipitate carbonate shells is a clearly identified risk. The impact depends on the significance of these organisms in Southern Ocean ecosystems, but there is very little information on their abundance or distribution. To quantify their presence, we used coulometric measurement of particulate inorganic carbonate (PIC) on particles filtered from surface seawater into two size fractions: 50–1000 µm to capture foraminifera (the most important biogenic carbonate-forming zooplankton) and 1–50 µm to capture coccolithophores (the most important biogenic carbonate-forming phytoplankton). Ancillary measurements of biogenic silica (BSi) and particulate organic carbon (POC) provided context, as estimates of the biomass of diatoms (the highest biomass phytoplankton in polar waters) and total microbial biomass, respectively. Results for nine transects from Australia to Antarctica in 2008–2015 showed low levels of PIC compared to Northern Hemisphere polar waters. Coccolithophores slightly exceeded the biomass of diatoms in subantarctic waters, but their abundance decreased more than 30-fold poleward, while diatom abundances increased, so that on a molar basis PIC was only 1 % of BSi in Antarctic waters. This limited importance of coccolithophores in the Southern Ocean is further emphasized in terms of their associated POC, representing less than 1 % of total POC in Antarctic waters and less than 10 % in subantarctic waters. NASA satellite ocean-colour-based PIC estimates were in reasonable agreement with the shipboard results in subantarctic waters but greatly overestimated PIC in Antarctic waters. Contrastingly, the NASA Ocean Biogeochemical Model (NOBM) shows coccolithophores as overly restricted to subtropical and northern subantarctic ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Ocean acidification Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean Biogeosciences 15 1 31 49 |
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English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 T. W. Trull A. Passmore D. M. Davies T. Smit K. Berry B. Tilbrook Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The Southern Ocean provides a vital service by absorbing about one-sixth of humankind's annual emissions of CO 2 . This comes with a cost – an increase in ocean acidity that is expected to have negative impacts on ocean ecosystems. The reduced ability of phytoplankton and zooplankton to precipitate carbonate shells is a clearly identified risk. The impact depends on the significance of these organisms in Southern Ocean ecosystems, but there is very little information on their abundance or distribution. To quantify their presence, we used coulometric measurement of particulate inorganic carbonate (PIC) on particles filtered from surface seawater into two size fractions: 50–1000 µm to capture foraminifera (the most important biogenic carbonate-forming zooplankton) and 1–50 µm to capture coccolithophores (the most important biogenic carbonate-forming phytoplankton). Ancillary measurements of biogenic silica (BSi) and particulate organic carbon (POC) provided context, as estimates of the biomass of diatoms (the highest biomass phytoplankton in polar waters) and total microbial biomass, respectively. Results for nine transects from Australia to Antarctica in 2008–2015 showed low levels of PIC compared to Northern Hemisphere polar waters. Coccolithophores slightly exceeded the biomass of diatoms in subantarctic waters, but their abundance decreased more than 30-fold poleward, while diatom abundances increased, so that on a molar basis PIC was only 1 % of BSi in Antarctic waters. This limited importance of coccolithophores in the Southern Ocean is further emphasized in terms of their associated POC, representing less than 1 % of total POC in Antarctic waters and less than 10 % in subantarctic waters. NASA satellite ocean-colour-based PIC estimates were in reasonable agreement with the shipboard results in subantarctic waters but greatly overestimated PIC in Antarctic waters. Contrastingly, the NASA Ocean Biogeochemical Model (NOBM) shows coccolithophores as overly restricted to subtropical and northern subantarctic ... |
format |
Article in Journal/Newspaper |
author |
T. W. Trull A. Passmore D. M. Davies T. Smit K. Berry B. Tilbrook |
author_facet |
T. W. Trull A. Passmore D. M. Davies T. Smit K. Berry B. Tilbrook |
author_sort |
T. W. Trull |
title |
Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment |
title_short |
Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment |
title_full |
Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment |
title_fullStr |
Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment |
title_full_unstemmed |
Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment |
title_sort |
distribution of planktonic biogenic carbonate organisms in the southern ocean south of australia: a baseline for ocean acidification impact assessment |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-15-31-2018 https://doaj.org/article/a80fcd51389046188bc11e4db5c34097 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctica Ocean acidification Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ocean acidification Southern Ocean |
op_source |
Biogeosciences, Vol 15, Pp 31-49 (2018) |
op_relation |
https://www.biogeosciences.net/15/31/2018/bg-15-31-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-31-2018 1726-4170 1726-4189 https://doaj.org/article/a80fcd51389046188bc11e4db5c34097 |
op_doi |
https://doi.org/10.5194/bg-15-31-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
1 |
container_start_page |
31 |
op_container_end_page |
49 |
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1766273760558579712 |