Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean
The Kerguelen Plateau is a region of natural iron fertilization in the Southern Ocean, within the typically iron limited High Nutrient Low Chlorophyll (HNLC) waters of the eastward flowing Antarctic Circumpolar Current. Between 26 February and 19 March 2018, the MOBYDICK expedition investigated pela...
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Elsevier BV
2021
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Online Access: | https://archimer.ifremer.fr/doc/00718/82993/87869.pdf https://doi.org/10.1016/j.jmarsys.2021.103625 https://archimer.ifremer.fr/doc/00718/82993/ |
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ftarchimer:oai:archimer.ifremer.fr:82993 2024-02-11T09:57:11+01:00 Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean Hunt, Brian P.v. Espinasse, Boris Pakhomov, Evgeny A. Cherel, Yves Cotté, Cedric Delegrange, Alice Henschke, Natasha 2021-12 application/pdf https://archimer.ifremer.fr/doc/00718/82993/87869.pdf https://doi.org/10.1016/j.jmarsys.2021.103625 https://archimer.ifremer.fr/doc/00718/82993/ eng eng Elsevier BV https://archimer.ifremer.fr/doc/00718/82993/87869.pdf doi:10.1016/j.jmarsys.2021.103625 https://archimer.ifremer.fr/doc/00718/82993/ info:eu-repo/semantics/openAccess restricted use Journal Of Marine Systems (0924-7963) (Elsevier BV), 2021-12 , Vol. 224 , P. 103625 (10p.) Zooplankton Micronekton Food web Size structure Stable isotopes Southern Ocean Kerguelen plateau text Article info:eu-repo/semantics/article 2021 ftarchimer https://doi.org/10.1016/j.jmarsys.2021.103625 2024-01-16T23:51:06Z The Kerguelen Plateau is a region of natural iron fertilization in the Southern Ocean, within the typically iron limited High Nutrient Low Chlorophyll (HNLC) waters of the eastward flowing Antarctic Circumpolar Current. Between 26 February and 19 March 2018, the MOBYDICK expedition investigated pelagic ecosystem dynamics in the Kerguelen Island region on the northern plateau during the post-phytoplankton bloom period. The survey specifically targeted sampling at two stations in the HNLC waters to the west of the Kerguelen Plateau, and in the iron enriched waters on and to the east of the plateau. A combination of WP2, WP3 and Mesopelagos midwater trawl were used to sample the mesozooplankton (125 μm to ≤10 mm), macrozooplankton (10–30 mm) and micronekton (> 30 to 200 mm) communities. Stable carbon (δ13C) and nitrogen (δ15N) isotopes were measured across representative samples of taxa from all stations. Trophic positions was estimated using a Bayesian isotope mixing model (tRophicPosition), that uses both the δ13C and δ15N values of baselines and consumers. Meso/macrozooplankton trophic positions (TPs) were ~ 2.4 on the plateau and > 0.6 TPs higher at the upstream HNLC stations. This provides empirical evidence for shorter food chains on the diatom dominated plateau and longer food chains in the HNLC region dominated by pico and nanophytopklankon. Meso/macrozooplankton TPs were also elevated downstream of the plateau, though to a lesser extent than in the upstream region, likely reflecting the effect of downstream iron transport, supporting elevated phytoplankton production in the downstream region. There was a consistent increase in trophic position between meso/macrozooplankton and micronekton of ~0.6 at all stations. Food chain length was therefore determined by the composition of the trophic levels below micronekton. Similar trophic structure at the two upstream HNLC stations, on either side of the northern branch of the Polar Front, indicated that food chain length was robust to the differences in ... Article in Journal/Newspaper Antarc* Antarctic Kerguelen Islands Mesozooplankton Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic Southern Ocean Kerguelen Kerguelen Islands Kerguelen Island ENVELOPE(69.500,69.500,-49.250,-49.250) Journal of Marine Systems 224 103625 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Zooplankton Micronekton Food web Size structure Stable isotopes Southern Ocean Kerguelen plateau |
spellingShingle |
Zooplankton Micronekton Food web Size structure Stable isotopes Southern Ocean Kerguelen plateau Hunt, Brian P.v. Espinasse, Boris Pakhomov, Evgeny A. Cherel, Yves Cotté, Cedric Delegrange, Alice Henschke, Natasha Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean |
topic_facet |
Zooplankton Micronekton Food web Size structure Stable isotopes Southern Ocean Kerguelen plateau |
description |
The Kerguelen Plateau is a region of natural iron fertilization in the Southern Ocean, within the typically iron limited High Nutrient Low Chlorophyll (HNLC) waters of the eastward flowing Antarctic Circumpolar Current. Between 26 February and 19 March 2018, the MOBYDICK expedition investigated pelagic ecosystem dynamics in the Kerguelen Island region on the northern plateau during the post-phytoplankton bloom period. The survey specifically targeted sampling at two stations in the HNLC waters to the west of the Kerguelen Plateau, and in the iron enriched waters on and to the east of the plateau. A combination of WP2, WP3 and Mesopelagos midwater trawl were used to sample the mesozooplankton (125 μm to ≤10 mm), macrozooplankton (10–30 mm) and micronekton (> 30 to 200 mm) communities. Stable carbon (δ13C) and nitrogen (δ15N) isotopes were measured across representative samples of taxa from all stations. Trophic positions was estimated using a Bayesian isotope mixing model (tRophicPosition), that uses both the δ13C and δ15N values of baselines and consumers. Meso/macrozooplankton trophic positions (TPs) were ~ 2.4 on the plateau and > 0.6 TPs higher at the upstream HNLC stations. This provides empirical evidence for shorter food chains on the diatom dominated plateau and longer food chains in the HNLC region dominated by pico and nanophytopklankon. Meso/macrozooplankton TPs were also elevated downstream of the plateau, though to a lesser extent than in the upstream region, likely reflecting the effect of downstream iron transport, supporting elevated phytoplankton production in the downstream region. There was a consistent increase in trophic position between meso/macrozooplankton and micronekton of ~0.6 at all stations. Food chain length was therefore determined by the composition of the trophic levels below micronekton. Similar trophic structure at the two upstream HNLC stations, on either side of the northern branch of the Polar Front, indicated that food chain length was robust to the differences in ... |
format |
Article in Journal/Newspaper |
author |
Hunt, Brian P.v. Espinasse, Boris Pakhomov, Evgeny A. Cherel, Yves Cotté, Cedric Delegrange, Alice Henschke, Natasha |
author_facet |
Hunt, Brian P.v. Espinasse, Boris Pakhomov, Evgeny A. Cherel, Yves Cotté, Cedric Delegrange, Alice Henschke, Natasha |
author_sort |
Hunt, Brian P.v. |
title |
Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean |
title_short |
Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean |
title_full |
Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean |
title_fullStr |
Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean |
title_full_unstemmed |
Pelagic food web structure in high nutrient low chlorophyll (HNLC) and naturally iron fertilized waters in the Kerguelen Islands region, Southern Ocean |
title_sort |
pelagic food web structure in high nutrient low chlorophyll (hnlc) and naturally iron fertilized waters in the kerguelen islands region, southern ocean |
publisher |
Elsevier BV |
publishDate |
2021 |
url |
https://archimer.ifremer.fr/doc/00718/82993/87869.pdf https://doi.org/10.1016/j.jmarsys.2021.103625 https://archimer.ifremer.fr/doc/00718/82993/ |
long_lat |
ENVELOPE(69.500,69.500,-49.250,-49.250) |
geographic |
Antarctic Southern Ocean Kerguelen Kerguelen Islands Kerguelen Island |
geographic_facet |
Antarctic Southern Ocean Kerguelen Kerguelen Islands Kerguelen Island |
genre |
Antarc* Antarctic Kerguelen Islands Mesozooplankton Southern Ocean |
genre_facet |
Antarc* Antarctic Kerguelen Islands Mesozooplankton Southern Ocean |
op_source |
Journal Of Marine Systems (0924-7963) (Elsevier BV), 2021-12 , Vol. 224 , P. 103625 (10p.) |
op_relation |
https://archimer.ifremer.fr/doc/00718/82993/87869.pdf doi:10.1016/j.jmarsys.2021.103625 https://archimer.ifremer.fr/doc/00718/82993/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1016/j.jmarsys.2021.103625 |
container_title |
Journal of Marine Systems |
container_volume |
224 |
container_start_page |
103625 |
_version_ |
1790609289432268800 |