Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean
Salp fecal pellets are rich in organic matter and have been shown to sink at very high velocities. In recent years, salp abundances have been increasing in the Southern Ocean where they seem to be replacing krill as the dominant grazers on phytoplankton. As salps can form large swarms with high pell...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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ftawi:oai:epic.awi.de:43297 2024-09-15T18:37:02+00:00 Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean Iversen, M. H. Pakhomov, E. A. Hunt, B. P. V. van der Jagt, H. Wolf-Gladrow, D. A. Klaas, C. 2016-12 https://epic.awi.de/id/eprint/43297/ https://doi.org/10.1016/j.dsr2.2016.12.004 unknown Iversen, M. H. orcid:0000-0002-5287-1110 , Pakhomov, E. A. , Hunt, B. P. V. , van der Jagt, H. , Wolf-Gladrow, D. A. orcid:0000-0001-9531-8668 and Klaas, C. orcid:0000-0002-6679-8970 (2016) Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean , Deep-Sea Research II . doi:10.1016/j.dsr2.2016.12.004 <https://doi.org/10.1016/j.dsr2.2016.12.004> EPIC3Deep-Sea Research II Article isiRev 2016 ftawi https://doi.org/10.1016/j.dsr2.2016.12.004 2024-06-24T04:16:35Z Salp fecal pellets are rich in organic matter and have been shown to sink at very high velocities. In recent years, salp abundances have been increasing in the Southern Ocean where they seem to be replacing krill as the dominant grazers on phytoplankton. As salps can form large swarms with high pellet production rates, it has been suggested that they will become increasingly important for the vertical export of particulate organic matter in the Southern Ocean. However, detailed studies combining both investigations of pellet production rates, turnover, and export are still needed in order to determine whether salp pellets are important for export (‘sinkers’) or recycling (‘floaters’) of organic matter. Our results suggest that pellets are produced at high rates in the upper few hundred meters of the water column. Although we observed high sinking velocities and low microbial degradation rates of the produced salp pellets, only about one third of the produced pellets were captured in sediment traps placed at 100 m and about ~13% of the produced pellets were exported to sediment traps placed at 300 m. The high retention of these fast-settling pellets seems to be caused by break-up and loosening of the pellets, possibly by zooplankton and salps themselves. We measured 3-fold lower size-specific sinking velocities in loosened and fragmented compared to freshly produced intact pellets-. This enhanced the residence times ( > 1 day) of both small and large pellets in the upper water column. We postulate that the fragile nature of salp pellets make them more important for recycling of organic matter in the upper mesopelagic layer rather than as a conduit for export of particulate organic matter to the seafloor. Article in Journal/Newspaper Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Deep Sea Research Part II: Topical Studies in Oceanography 138 116 125 |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Salp fecal pellets are rich in organic matter and have been shown to sink at very high velocities. In recent years, salp abundances have been increasing in the Southern Ocean where they seem to be replacing krill as the dominant grazers on phytoplankton. As salps can form large swarms with high pellet production rates, it has been suggested that they will become increasingly important for the vertical export of particulate organic matter in the Southern Ocean. However, detailed studies combining both investigations of pellet production rates, turnover, and export are still needed in order to determine whether salp pellets are important for export (‘sinkers’) or recycling (‘floaters’) of organic matter. Our results suggest that pellets are produced at high rates in the upper few hundred meters of the water column. Although we observed high sinking velocities and low microbial degradation rates of the produced salp pellets, only about one third of the produced pellets were captured in sediment traps placed at 100 m and about ~13% of the produced pellets were exported to sediment traps placed at 300 m. The high retention of these fast-settling pellets seems to be caused by break-up and loosening of the pellets, possibly by zooplankton and salps themselves. We measured 3-fold lower size-specific sinking velocities in loosened and fragmented compared to freshly produced intact pellets-. This enhanced the residence times ( > 1 day) of both small and large pellets in the upper water column. We postulate that the fragile nature of salp pellets make them more important for recycling of organic matter in the upper mesopelagic layer rather than as a conduit for export of particulate organic matter to the seafloor. |
format |
Article in Journal/Newspaper |
author |
Iversen, M. H. Pakhomov, E. A. Hunt, B. P. V. van der Jagt, H. Wolf-Gladrow, D. A. Klaas, C. |
spellingShingle |
Iversen, M. H. Pakhomov, E. A. Hunt, B. P. V. van der Jagt, H. Wolf-Gladrow, D. A. Klaas, C. Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean |
author_facet |
Iversen, M. H. Pakhomov, E. A. Hunt, B. P. V. van der Jagt, H. Wolf-Gladrow, D. A. Klaas, C. |
author_sort |
Iversen, M. H. |
title |
Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean |
title_short |
Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean |
title_full |
Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean |
title_fullStr |
Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean |
title_full_unstemmed |
Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean |
title_sort |
sinkers or floaters? contribution from salp pellets to the export flux during a large bloom event in the southern ocean |
publishDate |
2016 |
url |
https://epic.awi.de/id/eprint/43297/ https://doi.org/10.1016/j.dsr2.2016.12.004 |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
EPIC3Deep-Sea Research II |
op_relation |
Iversen, M. H. orcid:0000-0002-5287-1110 , Pakhomov, E. A. , Hunt, B. P. V. , van der Jagt, H. , Wolf-Gladrow, D. A. orcid:0000-0001-9531-8668 and Klaas, C. orcid:0000-0002-6679-8970 (2016) Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean , Deep-Sea Research II . doi:10.1016/j.dsr2.2016.12.004 <https://doi.org/10.1016/j.dsr2.2016.12.004> |
op_doi |
https://doi.org/10.1016/j.dsr2.2016.12.004 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
138 |
container_start_page |
116 |
op_container_end_page |
125 |
_version_ |
1810481299505283072 |