Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp.
The stable isotope composition of benthic sponge spicule silica is a potential source of palaeoceanographic information about past deep seawater chemistry. The silicon isotope composition of spicules has been shown to relate to the silicic acid concentration of ambient water, although existing calib...
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Online Access: | http://hdl.handle.net/1834/17082 https://doi.org/10.5194/bg-12-3489-2015 |
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ftoceandocs:oai:aquadocs.org:1834/17082 2024-06-09T07:49:45+00:00 Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. Hendry, K. Swann, G. Leng, M. Sloane, H. Goodwin, C. Berman, J. Maldonado, M. 2015 pp.3489-3498 http://hdl.handle.net/1834/17082 https://doi.org/10.5194/bg-12-3489-2015 en eng https://doi.org/10.5194/bg-12-3489-2015 http://hdl.handle.net/1834/17082 Journal Contribution Refereed 2015 ftoceandocs https://doi.org/10.5194/bg-12-3489-2015 2024-05-15T08:02:16Z The stable isotope composition of benthic sponge spicule silica is a potential source of palaeoceanographic information about past deep seawater chemistry. The silicon isotope composition of spicules has been shown to relate to the silicic acid concentration of ambient water, although existing calibrations do exhibit a degree of scatter in the relationship. Less is known about how the oxygen isotope composition of sponge spicule silica relates to environmental conditions during growth. Here, we investigate the vital effects on silica, silicon and oxygen isotope composition in a carnivorous sponge, Asbestopluma sp., from the Southern Ocean. We find significant variations in silicon and oxygen isotopic composition within the specimen that are related to unusual spicule silicification. The largest variation in both isotope systems was associated with the differential distribution of an unconventional, hypersilicified spicule type (desma) along the sponge body. The absence an internal canal in the desmas suggests an unconventional silicification pattern leading to an unusually heavy isotope signature. Additional internal variability derives from a systematic offset between the peripheral skeleton of the body having systematically a higher isotopic composition than the internal skeleton. A simplified silicon isotope fractionation model, in which desmas were excluded, suggests that the lack of a system for seawater pumping in carnivorous sponges favours a low replenishment of dissolved silicon within the internal tissues, causing kinetic fractionation during silicification that impacts the isotope signature of the internal skeleton. Analysis of multiple spicules should be carried out to "average out" any artefacts in order to produce more robust downcore measurements. Published Book Southern Ocean IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications Southern Ocean Biogeosciences 12 11 3489 3498 |
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Open Polar |
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IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications |
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ftoceandocs |
language |
English |
description |
The stable isotope composition of benthic sponge spicule silica is a potential source of palaeoceanographic information about past deep seawater chemistry. The silicon isotope composition of spicules has been shown to relate to the silicic acid concentration of ambient water, although existing calibrations do exhibit a degree of scatter in the relationship. Less is known about how the oxygen isotope composition of sponge spicule silica relates to environmental conditions during growth. Here, we investigate the vital effects on silica, silicon and oxygen isotope composition in a carnivorous sponge, Asbestopluma sp., from the Southern Ocean. We find significant variations in silicon and oxygen isotopic composition within the specimen that are related to unusual spicule silicification. The largest variation in both isotope systems was associated with the differential distribution of an unconventional, hypersilicified spicule type (desma) along the sponge body. The absence an internal canal in the desmas suggests an unconventional silicification pattern leading to an unusually heavy isotope signature. Additional internal variability derives from a systematic offset between the peripheral skeleton of the body having systematically a higher isotopic composition than the internal skeleton. A simplified silicon isotope fractionation model, in which desmas were excluded, suggests that the lack of a system for seawater pumping in carnivorous sponges favours a low replenishment of dissolved silicon within the internal tissues, causing kinetic fractionation during silicification that impacts the isotope signature of the internal skeleton. Analysis of multiple spicules should be carried out to "average out" any artefacts in order to produce more robust downcore measurements. Published |
format |
Book |
author |
Hendry, K. Swann, G. Leng, M. Sloane, H. Goodwin, C. Berman, J. Maldonado, M. |
spellingShingle |
Hendry, K. Swann, G. Leng, M. Sloane, H. Goodwin, C. Berman, J. Maldonado, M. Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. |
author_facet |
Hendry, K. Swann, G. Leng, M. Sloane, H. Goodwin, C. Berman, J. Maldonado, M. |
author_sort |
Hendry, K. |
title |
Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. |
title_short |
Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. |
title_full |
Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. |
title_fullStr |
Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. |
title_full_unstemmed |
Technical Note: Silica stable isotopes and silicification in a carnivorous sponge Asbestopluma sp. |
title_sort |
technical note: silica stable isotopes and silicification in a carnivorous sponge asbestopluma sp. |
publishDate |
2015 |
url |
http://hdl.handle.net/1834/17082 https://doi.org/10.5194/bg-12-3489-2015 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://doi.org/10.5194/bg-12-3489-2015 http://hdl.handle.net/1834/17082 |
op_doi |
https://doi.org/10.5194/bg-12-3489-2015 |
container_title |
Biogeosciences |
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12 |
container_issue |
11 |
container_start_page |
3489 |
op_container_end_page |
3498 |
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1801382546288672768 |