Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references. Euphau...
Main Author: | |
---|---|
Format: | Thesis |
Language: | English |
Published: |
Texas A&M University
1994
|
Subjects: | |
Online Access: | https://hdl.handle.net/1969.1/ETD-TAMU-1994-THESIS-Y37 |
id |
fttexasamuniv:oai:oaktrust.library.tamu.edu:1969.1/ETD-TAMU-1994-THESIS-Y37 |
---|---|
record_format |
openpolar |
spelling |
fttexasamuniv:oai:oaktrust.library.tamu.edu:1969.1/ETD-TAMU-1994-THESIS-Y37 2023-07-16T03:53:12+02:00 Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica Yeager, Marilyn Smith 1994 electronic application/pdf reformatted digital https://hdl.handle.net/1969.1/ETD-TAMU-1994-THESIS-Y37 en_US eng Texas A&M University https://hdl.handle.net/1969.1/ETD-TAMU-1994-THESIS-Y37 This thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use. oceanography Major oceanography Thesis text 1994 fttexasamuniv 2023-06-27T22:16:36Z Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references. Euphausia superba aggregations were sampled with a Multiple Opening/Closing Net and Environmental Sensor System (MOCNESS) during the austral summer 1991-92 Antarctic Marine Living Resources (AMLR) survey in the vicinity of Elephant Island, Antarctica. Four areas of high krill concentrations were identified with a towed l2OkHz single frequency spift-beam acoustic transponder. Discrete samples were collected at user-designated depths to examine length and developmental stage variability vertically and horizontally within aggregations and to determine the influence of physical and biological factors on Euphausia superba distributions. The MOCNESS study area included a major hydrographic front marking the mixing of Weddell Scotia Confluence (WSC) and Antarctic Surface Water (AASW). On the spatial mesoscale, Euphausia superba distributions showed a distinct separation of length and developmental stages by water mass, with juveniles <30mm associated with WSC in shallower shelf waters and adult krill >45 mm associated with Transition Type 11 water and the presence of Circumpolar Deep Water (CDW) on the west shelf and slope. There were significant differences in Euphausia superba length distribution and the proportion of developmental stages between the thermocline and mixed layer that varied with the diel period of the samples and the degree of water stratification. These data suggest vertical diel migration by Euphausia superba which may have been affected by the degree of water stratification, which in turn may influence phytoplankton population growth. On a spatial fine-scale, vertical stratification of krill with significantly different mean lengths and proportions of developmental stages were observed in the mixed ... Thesis Antarc* Antarctic Antarctica Elephant Island Euphausia superba Texas A&M University Digital Repository Antarctic Austral Elephant Island ENVELOPE(-55.184,-55.184,-61.085,-61.085) Weddell |
institution |
Open Polar |
collection |
Texas A&M University Digital Repository |
op_collection_id |
fttexasamuniv |
language |
English |
topic |
oceanography Major oceanography |
spellingShingle |
oceanography Major oceanography Yeager, Marilyn Smith Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica |
topic_facet |
oceanography Major oceanography |
description |
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references. Euphausia superba aggregations were sampled with a Multiple Opening/Closing Net and Environmental Sensor System (MOCNESS) during the austral summer 1991-92 Antarctic Marine Living Resources (AMLR) survey in the vicinity of Elephant Island, Antarctica. Four areas of high krill concentrations were identified with a towed l2OkHz single frequency spift-beam acoustic transponder. Discrete samples were collected at user-designated depths to examine length and developmental stage variability vertically and horizontally within aggregations and to determine the influence of physical and biological factors on Euphausia superba distributions. The MOCNESS study area included a major hydrographic front marking the mixing of Weddell Scotia Confluence (WSC) and Antarctic Surface Water (AASW). On the spatial mesoscale, Euphausia superba distributions showed a distinct separation of length and developmental stages by water mass, with juveniles <30mm associated with WSC in shallower shelf waters and adult krill >45 mm associated with Transition Type 11 water and the presence of Circumpolar Deep Water (CDW) on the west shelf and slope. There were significant differences in Euphausia superba length distribution and the proportion of developmental stages between the thermocline and mixed layer that varied with the diel period of the samples and the degree of water stratification. These data suggest vertical diel migration by Euphausia superba which may have been affected by the degree of water stratification, which in turn may influence phytoplankton population growth. On a spatial fine-scale, vertical stratification of krill with significantly different mean lengths and proportions of developmental stages were observed in the mixed ... |
format |
Thesis |
author |
Yeager, Marilyn Smith |
author_facet |
Yeager, Marilyn Smith |
author_sort |
Yeager, Marilyn Smith |
title |
Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica |
title_short |
Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica |
title_full |
Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica |
title_fullStr |
Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica |
title_full_unstemmed |
Biological characteristics of Uphausia superba dan in acoustically detected aggregations near Elephant Island, Antarctica |
title_sort |
biological characteristics of uphausia superba dan in acoustically detected aggregations near elephant island, antarctica |
publisher |
Texas A&M University |
publishDate |
1994 |
url |
https://hdl.handle.net/1969.1/ETD-TAMU-1994-THESIS-Y37 |
long_lat |
ENVELOPE(-55.184,-55.184,-61.085,-61.085) |
geographic |
Antarctic Austral Elephant Island Weddell |
geographic_facet |
Antarctic Austral Elephant Island Weddell |
genre |
Antarc* Antarctic Antarctica Elephant Island Euphausia superba |
genre_facet |
Antarc* Antarctic Antarctica Elephant Island Euphausia superba |
op_relation |
https://hdl.handle.net/1969.1/ETD-TAMU-1994-THESIS-Y37 |
op_rights |
This thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use. |
_version_ |
1771549190954942464 |