Evidence for ocean acidification in the Great Barrier Reef of Australia
Geochemical records preserved in the long-lived carbonate skeleton of corals provide one of the few means to reconstruct changes in seawater pH since the commencement of the industrial era. This information is important in not only determining the response of the surface oceans to ocean acidificatio...
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Online Access: | http://hdl.handle.net/1885/54914 https://doi.org/10.1016/j.gca.2009.02.009 https://openresearch-repository.anu.edu.au/bitstream/1885/54914/5/GeCA73_2332.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/54914/7/01_Wei_Evidence_for_ocean_2009.pdf.jpg |
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/54914 2024-01-14T10:09:36+01:00 Evidence for ocean acidification in the Great Barrier Reef of Australia Wei, Gangjian McCulloch, Malcolm Mortimer, Graham Deng, Wenfeng Xie, Luhua http://hdl.handle.net/1885/54914 https://doi.org/10.1016/j.gca.2009.02.009 https://openresearch-repository.anu.edu.au/bitstream/1885/54914/5/GeCA73_2332.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/54914/7/01_Wei_Evidence_for_ocean_2009.pdf.jpg unknown Pergamon-Elsevier Ltd 1872-9533 http://hdl.handle.net/1885/54914 doi:10.1016/j.gca.2009.02.009 https://openresearch-repository.anu.edu.au/bitstream/1885/54914/5/GeCA73_2332.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/54914/7/01_Wei_Evidence_for_ocean_2009.pdf.jpg Geochimica et Cosmochimica Acta Keywords: acidification calcification carbon coral reef hydrogeochemistry ionization isotopic composition mass spectrometry pH seawater Australasia Australia Coral Sea Great Barrier Reef Pacific Ocean Queensland Anthozoa Porites Journal article ftanucanberra https://doi.org/10.1016/j.gca.2009.02.009 2023-12-15T09:33:50Z Geochemical records preserved in the long-lived carbonate skeleton of corals provide one of the few means to reconstruct changes in seawater pH since the commencement of the industrial era. This information is important in not only determining the response of the surface oceans to ocean acidification from enhanced uptake of CO2, but also to better understand the effects of ocean acidification on carbonate secreting organisms such as corals, whose ability to calcify is highly pH dependent. Here we report an ∼200 year δ11B isotopic record, extracted from a long-lived Porites coral from the central Great Barrier Reef of Australia. This record covering the period from 1800 to 2004 was sampled at yearly increments from 1940 to the present and 5-year increments prior to 1940. The δ11B isotopic compositions reflect variations in seawater pH, and the δ13C changes in the carbon composition of surface water due to fossil fuel burning over this period. In addition complementary Ba/Ca, δ18O and Mg/Ca data was obtained providing proxies for terrestrial runoff, salinity and temperature changes over the past 200 years in this region. Positive thermal ionization mass spectrometry (PTIMS) method was utilized in order to enable the highest precision and most accurate measurements of δ11B values. The internal precision and reproducibility for δ11B of our measurements are better than ±0.2‰ (2σ), which translates to a precision of better than ±0.02 pH units. Our results indicate that the long-term pre-industrial variation of seawater pH in this region is partially related to the decadal-interdecadal variability of atmospheric and oceanic anomalies in the Pacific. In the periods around 1940 and 1998 there are also rapid oscillations in δ11B compositions equivalent changes in pH of almost 0.5 U. The 1998 oscillation is co-incident with a major coral bleaching event indicating the sensitivity of skeletal δ11B compositions to loss of zooxanthellate symbionts. Importantly, from the 1940s to the present-day, there is a general overall ... Article in Journal/Newspaper Ocean acidification Australian National University: ANU Digital Collections Pacific Queensland Geochimica et Cosmochimica Acta 73 8 2332 2346 |
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Open Polar |
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Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: acidification calcification carbon coral reef hydrogeochemistry ionization isotopic composition mass spectrometry pH seawater Australasia Australia Coral Sea Great Barrier Reef Pacific Ocean Queensland Anthozoa Porites |
spellingShingle |
Keywords: acidification calcification carbon coral reef hydrogeochemistry ionization isotopic composition mass spectrometry pH seawater Australasia Australia Coral Sea Great Barrier Reef Pacific Ocean Queensland Anthozoa Porites Wei, Gangjian McCulloch, Malcolm Mortimer, Graham Deng, Wenfeng Xie, Luhua Evidence for ocean acidification in the Great Barrier Reef of Australia |
topic_facet |
Keywords: acidification calcification carbon coral reef hydrogeochemistry ionization isotopic composition mass spectrometry pH seawater Australasia Australia Coral Sea Great Barrier Reef Pacific Ocean Queensland Anthozoa Porites |
description |
Geochemical records preserved in the long-lived carbonate skeleton of corals provide one of the few means to reconstruct changes in seawater pH since the commencement of the industrial era. This information is important in not only determining the response of the surface oceans to ocean acidification from enhanced uptake of CO2, but also to better understand the effects of ocean acidification on carbonate secreting organisms such as corals, whose ability to calcify is highly pH dependent. Here we report an ∼200 year δ11B isotopic record, extracted from a long-lived Porites coral from the central Great Barrier Reef of Australia. This record covering the period from 1800 to 2004 was sampled at yearly increments from 1940 to the present and 5-year increments prior to 1940. The δ11B isotopic compositions reflect variations in seawater pH, and the δ13C changes in the carbon composition of surface water due to fossil fuel burning over this period. In addition complementary Ba/Ca, δ18O and Mg/Ca data was obtained providing proxies for terrestrial runoff, salinity and temperature changes over the past 200 years in this region. Positive thermal ionization mass spectrometry (PTIMS) method was utilized in order to enable the highest precision and most accurate measurements of δ11B values. The internal precision and reproducibility for δ11B of our measurements are better than ±0.2‰ (2σ), which translates to a precision of better than ±0.02 pH units. Our results indicate that the long-term pre-industrial variation of seawater pH in this region is partially related to the decadal-interdecadal variability of atmospheric and oceanic anomalies in the Pacific. In the periods around 1940 and 1998 there are also rapid oscillations in δ11B compositions equivalent changes in pH of almost 0.5 U. The 1998 oscillation is co-incident with a major coral bleaching event indicating the sensitivity of skeletal δ11B compositions to loss of zooxanthellate symbionts. Importantly, from the 1940s to the present-day, there is a general overall ... |
format |
Article in Journal/Newspaper |
author |
Wei, Gangjian McCulloch, Malcolm Mortimer, Graham Deng, Wenfeng Xie, Luhua |
author_facet |
Wei, Gangjian McCulloch, Malcolm Mortimer, Graham Deng, Wenfeng Xie, Luhua |
author_sort |
Wei, Gangjian |
title |
Evidence for ocean acidification in the Great Barrier Reef of Australia |
title_short |
Evidence for ocean acidification in the Great Barrier Reef of Australia |
title_full |
Evidence for ocean acidification in the Great Barrier Reef of Australia |
title_fullStr |
Evidence for ocean acidification in the Great Barrier Reef of Australia |
title_full_unstemmed |
Evidence for ocean acidification in the Great Barrier Reef of Australia |
title_sort |
evidence for ocean acidification in the great barrier reef of australia |
publisher |
Pergamon-Elsevier Ltd |
url |
http://hdl.handle.net/1885/54914 https://doi.org/10.1016/j.gca.2009.02.009 https://openresearch-repository.anu.edu.au/bitstream/1885/54914/5/GeCA73_2332.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/54914/7/01_Wei_Evidence_for_ocean_2009.pdf.jpg |
geographic |
Pacific Queensland |
geographic_facet |
Pacific Queensland |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
Geochimica et Cosmochimica Acta |
op_relation |
1872-9533 http://hdl.handle.net/1885/54914 doi:10.1016/j.gca.2009.02.009 https://openresearch-repository.anu.edu.au/bitstream/1885/54914/5/GeCA73_2332.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/54914/7/01_Wei_Evidence_for_ocean_2009.pdf.jpg |
op_doi |
https://doi.org/10.1016/j.gca.2009.02.009 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
73 |
container_issue |
8 |
container_start_page |
2332 |
op_container_end_page |
2346 |
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1788064154326663168 |