Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths
The community structure and predation impact of carnivorous macrozooplankton (>2 cm; chaetognaths, medusae, ctenophores and mysids), with particular emphasis on the chaetognaths Eukrohnia hamata and Sagitta gazellae, were investigated during three surveys conducted in late austral summer (April/M...
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ftrhodesunivcory:vital:5653 2023-05-15T13:49:37+02:00 Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths Lukáč, Danica 2006 135 leaves pdf http://hdl.handle.net/10962/d1005336 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5653 English eng Rhodes University Faculty of Science, Zoology and Entomology vital:5653 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5653 http://hdl.handle.net/10962/d1005336 Lukáč, Danica Zooplankton -- Antarctic Ocean Chaetognatha Thesis Masters MSc 2006 ftrhodesunivcory 2022-12-26T10:58:34Z The community structure and predation impact of carnivorous macrozooplankton (>2 cm; chaetognaths, medusae, ctenophores and mysids), with particular emphasis on the chaetognaths Eukrohnia hamata and Sagitta gazellae, were investigated during three surveys conducted in late austral summer (April/May) of 2001, 2004 and 2005 in the Polar Frontal Zone in the vicinity of the Prince Edward Islands (46º45’S, 37º50’E), Southern Ocean. The 2001 survey formed part of the Marion Offshore Variability Ecosystem Study (MOVES II), while the 2004 and 2005 surveys formed part of the Dynamics of Eddy Impacts on Marion’s Ecosystem study (DEIMEC III and IV respectively). Macrozooplankton samples were collected using WP-2, RMT-8 and Bongo nets. Results of the hydrographic survey indicated that the region of investigation, the Polar Frontal Zone (PFZ), is an area of high mesoscale variability. During the 2004 survey the Antarctic Polar Front (APF) and the Subantarctic Front (SAF) merged to form an intense frontal feature with subsurface temperature and salinity ranging from 8.5-7.5ºC and 34.15-33.88, respectively. A cyclonic cold core eddy, believed to have been spawned from the APF, was observed during the 2005 survey. Macrozooplankton abundance and biomass ranged from 0 to 43.731 ind. m⁻³, and from 0 to 41.55 mg wwt m⁻³ respectively, during the three surveys. Among the carnivorous macrozooplankton, chaetognaths (Eukrohnia hamata and Sagitta gazellae) were most prominent, contributing up to 85% of the total biomass during all three surveys. Elevated biomass values were found near and within the frontal feature during the 2004 survey, and also along the eddy edge during the 2005 survey. However, hierarchical cluster analysis did not reveal the presence of distinct zooplankton groupings associated with the various water masses encountered during the surveys and this is probably due to the high mesoscale variability in oceanographic conditions that are characteristic of the PFZ. The total average predation impact of the selected ... Master Thesis Antarc* Antarctic Antarctic Ocean Prince Edward Islands Southern Ocean Rhodes University Cory: Repository Antarctic Antarctic Ocean Austral Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Rhodes University Cory: Repository |
op_collection_id |
ftrhodesunivcory |
language |
English |
topic |
Zooplankton -- Antarctic Ocean Chaetognatha |
spellingShingle |
Zooplankton -- Antarctic Ocean Chaetognatha Lukáč, Danica Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths |
topic_facet |
Zooplankton -- Antarctic Ocean Chaetognatha |
description |
The community structure and predation impact of carnivorous macrozooplankton (>2 cm; chaetognaths, medusae, ctenophores and mysids), with particular emphasis on the chaetognaths Eukrohnia hamata and Sagitta gazellae, were investigated during three surveys conducted in late austral summer (April/May) of 2001, 2004 and 2005 in the Polar Frontal Zone in the vicinity of the Prince Edward Islands (46º45’S, 37º50’E), Southern Ocean. The 2001 survey formed part of the Marion Offshore Variability Ecosystem Study (MOVES II), while the 2004 and 2005 surveys formed part of the Dynamics of Eddy Impacts on Marion’s Ecosystem study (DEIMEC III and IV respectively). Macrozooplankton samples were collected using WP-2, RMT-8 and Bongo nets. Results of the hydrographic survey indicated that the region of investigation, the Polar Frontal Zone (PFZ), is an area of high mesoscale variability. During the 2004 survey the Antarctic Polar Front (APF) and the Subantarctic Front (SAF) merged to form an intense frontal feature with subsurface temperature and salinity ranging from 8.5-7.5ºC and 34.15-33.88, respectively. A cyclonic cold core eddy, believed to have been spawned from the APF, was observed during the 2005 survey. Macrozooplankton abundance and biomass ranged from 0 to 43.731 ind. m⁻³, and from 0 to 41.55 mg wwt m⁻³ respectively, during the three surveys. Among the carnivorous macrozooplankton, chaetognaths (Eukrohnia hamata and Sagitta gazellae) were most prominent, contributing up to 85% of the total biomass during all three surveys. Elevated biomass values were found near and within the frontal feature during the 2004 survey, and also along the eddy edge during the 2005 survey. However, hierarchical cluster analysis did not reveal the presence of distinct zooplankton groupings associated with the various water masses encountered during the surveys and this is probably due to the high mesoscale variability in oceanographic conditions that are characteristic of the PFZ. The total average predation impact of the selected ... |
format |
Master Thesis |
author |
Lukáč, Danica |
author_facet |
Lukáč, Danica |
author_sort |
Lukáč, Danica |
title |
Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths |
title_short |
Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths |
title_full |
Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths |
title_fullStr |
Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths |
title_full_unstemmed |
Community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (Southern Ocean), with particular reference to chaetognaths |
title_sort |
community structure and predation impact of carnivorous macrozooplankton in the polar frontal zone (southern ocean), with particular reference to chaetognaths |
publisher |
Rhodes University |
publishDate |
2006 |
url |
http://hdl.handle.net/10962/d1005336 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5653 |
geographic |
Antarctic Antarctic Ocean Austral Southern Ocean The Antarctic |
geographic_facet |
Antarctic Antarctic Ocean Austral Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctic Ocean Prince Edward Islands Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Ocean Prince Edward Islands Southern Ocean |
op_relation |
vital:5653 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5653 http://hdl.handle.net/10962/d1005336 |
op_rights |
Lukáč, Danica |
_version_ |
1766251883450597376 |