THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH
International audience The influence of copepods (mainly Oithona similis) and krill (Euphausia superba) grazing on the species composition of plankton communities in ship-board containers was investigated during the spring and post-spring period in the Scotia-Weddell Sea in the Antarctic ocean. Numb...
Published in: | Polar Biology |
---|---|
Main Authors: | , , , , , , |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
1993
|
Subjects: | |
Online Access: | https://hal.science/hal-03476497 https://doi.org/10.1007/BF00238930 |
id |
ftsorbonneuniv:oai:HAL:hal-03476497v1 |
---|---|
record_format |
openpolar |
spelling |
ftsorbonneuniv:oai:HAL:hal-03476497v1 2024-09-15T17:47:48+00:00 THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH Fransz, G Cuzinroudy, J Alder, Va Graneli, E Graneli, W Rabbani, Mm Daugbjerg, N Station Zoologique de Villefranche Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) Department of Biology 1993 https://hal.science/hal-03476497 https://doi.org/10.1007/BF00238930 en eng HAL CCSD Springer Verlag info:eu-repo/semantics/altIdentifier/doi/10.1007/BF00238930 hal-03476497 https://hal.science/hal-03476497 doi:10.1007/BF00238930 ISSN: 0722-4060 EISSN: 1432-2056 Polar Biology https://hal.science/hal-03476497 Polar Biology, 1993, 13 (3), pp.201-213. ⟨10.1007/BF00238930⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 1993 ftsorbonneuniv https://doi.org/10.1007/BF00238930 2024-07-25T23:47:52Z International audience The influence of copepods (mainly Oithona similis) and krill (Euphausia superba) grazing on the species composition of plankton communities in ship-board containers was investigated during the spring and post-spring period in the Scotia-Weddell Sea in the Antarctic ocean. Numbers of grazers were experimentally manipulated in containers with natural phytoplankton assemblages. With natural levels of copepods but no krill a high (700 950 mug C . l-1, ca 30 mug chl a . l-1) phytoplankton biomass developed. In these cultures large diatoms, e.g. Corethron criophilum and chains of Thalassiosira sp., made up 80% of total phytoplankton cell carbon at the end of the experiment. In cultures with elevated numbers of copepods (5X or 10X the natural level) phytoplankton biomass was somewhat reduced (ca 23 mug chl a . l-1) compared to cultures with natural copepod abundance, but still high. Phytoplankton species composition was on the other hand greatly influenced. Instead of large diatoms these cultures were dominated by Phaeocystis pouchetii (70%) together with small Nitszchia sp. and Chaetoceros neogracile (20%). In containers with krill (both juveniles and adults), but without elevated numbers of copepods, phytoplankton biomass rapidly approached zero. With 10X the in situ level of copepods, krill first preyed on these before Corethron criophilum and Thalassiosira sp. were grazed. When krill were removed a plankton community dominated by flagellates (60-90%), e.g. Pyramimonas sp. and a Cryptophycean species, grazed by an unidentified droplet-shaped heterothrophic flagellate, developed. These flagellates were the same as those which dominated the plankton community in the Weddell Sea after the `spring bloom'. A similar succession was observed in situ when a krill swarm grazed down a phytoplankton `bloom' in a few hours. Our experiments show that copepods cannot control phytoplankton biomass in shipboard cultures even at artificially elevated numbers. Krill at concentrations similar to those in ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Ocean Euphausia superba Polar Biology Weddell Sea Copepods HAL Sorbonne Université Polar Biology 13 3 201 213 |
institution |
Open Polar |
collection |
HAL Sorbonne Université |
op_collection_id |
ftsorbonneuniv |
language |
English |
topic |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Fransz, G Cuzinroudy, J Alder, Va Graneli, E Graneli, W Rabbani, Mm Daugbjerg, N THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience The influence of copepods (mainly Oithona similis) and krill (Euphausia superba) grazing on the species composition of plankton communities in ship-board containers was investigated during the spring and post-spring period in the Scotia-Weddell Sea in the Antarctic ocean. Numbers of grazers were experimentally manipulated in containers with natural phytoplankton assemblages. With natural levels of copepods but no krill a high (700 950 mug C . l-1, ca 30 mug chl a . l-1) phytoplankton biomass developed. In these cultures large diatoms, e.g. Corethron criophilum and chains of Thalassiosira sp., made up 80% of total phytoplankton cell carbon at the end of the experiment. In cultures with elevated numbers of copepods (5X or 10X the natural level) phytoplankton biomass was somewhat reduced (ca 23 mug chl a . l-1) compared to cultures with natural copepod abundance, but still high. Phytoplankton species composition was on the other hand greatly influenced. Instead of large diatoms these cultures were dominated by Phaeocystis pouchetii (70%) together with small Nitszchia sp. and Chaetoceros neogracile (20%). In containers with krill (both juveniles and adults), but without elevated numbers of copepods, phytoplankton biomass rapidly approached zero. With 10X the in situ level of copepods, krill first preyed on these before Corethron criophilum and Thalassiosira sp. were grazed. When krill were removed a plankton community dominated by flagellates (60-90%), e.g. Pyramimonas sp. and a Cryptophycean species, grazed by an unidentified droplet-shaped heterothrophic flagellate, developed. These flagellates were the same as those which dominated the plankton community in the Weddell Sea after the `spring bloom'. A similar succession was observed in situ when a krill swarm grazed down a phytoplankton `bloom' in a few hours. Our experiments show that copepods cannot control phytoplankton biomass in shipboard cultures even at artificially elevated numbers. Krill at concentrations similar to those in ... |
author2 |
Station Zoologique de Villefranche Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) Department of Biology |
format |
Article in Journal/Newspaper |
author |
Fransz, G Cuzinroudy, J Alder, Va Graneli, E Graneli, W Rabbani, Mm Daugbjerg, N |
author_facet |
Fransz, G Cuzinroudy, J Alder, Va Graneli, E Graneli, W Rabbani, Mm Daugbjerg, N |
author_sort |
Fransz, G |
title |
THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH |
title_short |
THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH |
title_full |
THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH |
title_fullStr |
THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH |
title_full_unstemmed |
THE INFLUENCE OF COPEPOD AND KRILL GRAZING ON THE SPECIES COMPOSITION OF PHYTOPLANKTON COMMUNITIES FROM THE SCOTIA-WEDDELL-SEA - AN EXPERIMENTAL APPROACH |
title_sort |
influence of copepod and krill grazing on the species composition of phytoplankton communities from the scotia-weddell-sea - an experimental approach |
publisher |
HAL CCSD |
publishDate |
1993 |
url |
https://hal.science/hal-03476497 https://doi.org/10.1007/BF00238930 |
genre |
Antarc* Antarctic Antarctic Ocean Euphausia superba Polar Biology Weddell Sea Copepods |
genre_facet |
Antarc* Antarctic Antarctic Ocean Euphausia superba Polar Biology Weddell Sea Copepods |
op_source |
ISSN: 0722-4060 EISSN: 1432-2056 Polar Biology https://hal.science/hal-03476497 Polar Biology, 1993, 13 (3), pp.201-213. ⟨10.1007/BF00238930⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/BF00238930 hal-03476497 https://hal.science/hal-03476497 doi:10.1007/BF00238930 |
op_doi |
https://doi.org/10.1007/BF00238930 |
container_title |
Polar Biology |
container_volume |
13 |
container_issue |
3 |
container_start_page |
201 |
op_container_end_page |
213 |
_version_ |
1810497377571700736 |