Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers
Despite extensive studies on Weddell seals (Leptonychotes weddellii) in McMurdo Sound since the 1960s, uncertainty still remains regarding female foraging habits during the lactation period. Based on their large body mass at the start of lactation and large relative mass loss at the end, the current...
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ftunivcanter:oai:ir.canterbury.ac.nz:10092/10367 2023-05-15T13:55:49+02:00 Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers Lenky, Crystal 2012 application/pdf http://hdl.handle.net/10092/10367 https://doi.org/10.26021/6810 en eng University of Canterbury. Gateway Antarctica NZCU http://hdl.handle.net/10092/10367 http://dx.doi.org/10.26021/6810 Copyright Crystal Lenky https://canterbury.libguides.com/rights/theses Weddell seal osmolyte biomarker Antarctica feeding TMAO Theses / Dissertations 2012 ftunivcanter https://doi.org/10.26021/6810 2022-09-08T13:32:52Z Despite extensive studies on Weddell seals (Leptonychotes weddellii) in McMurdo Sound since the 1960s, uncertainty still remains regarding female foraging habits during the lactation period. Based on their large body mass at the start of lactation and large relative mass loss at the end, the current hypothesis is that Weddell seals fast or feed to a neglible extent during lactation. However, this hypothesis has not been fully tested to date, as evidence for foraging is indirect and is based primarily on dive behaviour. The work presented in this thesis describes the development of a new dietary method, the biomarker method, and its application for studying the foraging behaviour of female Weddell seals during lactation. Biomarkers were used to (1) monitor the onset of feeding in individual animals, and (2) determine what prey females were feeding on using characteristic/taxon-specific biomarker patterns. Proton nuclear magnetic resonance spectroscopy (1H NMR) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays were developed to detect and quantify dietary biomarkers in biological samples, mainly tissues, serum and plasma. Trimethylamine N-oxide, arsenobetaine, dimethylsulfoniopropionate, homarine and glycine betaine were first measured in thirty-three prey and potential prey species of Weddell seals collected from the Ross Sea and McMurdo Sound regions of Antarctica. These same compounds were then measured in the plasma of twelve female Weddell seals over the lactation period at the Hutton Cliffs seal colony, McMurdo Sound in 2006. Time-depth recorders monitored seal dive activity over the same period. The data obtained from both NMR and LC-MS/MS assays showed that biomarkers in Antarctic species varied both in content and concentration. The compound homarine, which occurs primarily in cephalopods, is suitable for distinguishing between major food groups of known prey of Weddell seals (i.e., fishes versus cephalopods). DMSP, a compound that occurs primarily in fish common in McMurdo Sound (e.g., ... Other/Unknown Material Antarc* Antarctic Antarctica McMurdo Sound Ross Sea Weddell Seal Weddell Seals University of Canterbury, Christchurch: UC Research Repository Antarctic Hutton Cliffs ENVELOPE(166.850,166.850,-77.733,-77.733) McMurdo Sound Ross Sea Weddell |
institution |
Open Polar |
collection |
University of Canterbury, Christchurch: UC Research Repository |
op_collection_id |
ftunivcanter |
language |
English |
topic |
Weddell seal osmolyte biomarker Antarctica feeding TMAO |
spellingShingle |
Weddell seal osmolyte biomarker Antarctica feeding TMAO Lenky, Crystal Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
topic_facet |
Weddell seal osmolyte biomarker Antarctica feeding TMAO |
description |
Despite extensive studies on Weddell seals (Leptonychotes weddellii) in McMurdo Sound since the 1960s, uncertainty still remains regarding female foraging habits during the lactation period. Based on their large body mass at the start of lactation and large relative mass loss at the end, the current hypothesis is that Weddell seals fast or feed to a neglible extent during lactation. However, this hypothesis has not been fully tested to date, as evidence for foraging is indirect and is based primarily on dive behaviour. The work presented in this thesis describes the development of a new dietary method, the biomarker method, and its application for studying the foraging behaviour of female Weddell seals during lactation. Biomarkers were used to (1) monitor the onset of feeding in individual animals, and (2) determine what prey females were feeding on using characteristic/taxon-specific biomarker patterns. Proton nuclear magnetic resonance spectroscopy (1H NMR) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays were developed to detect and quantify dietary biomarkers in biological samples, mainly tissues, serum and plasma. Trimethylamine N-oxide, arsenobetaine, dimethylsulfoniopropionate, homarine and glycine betaine were first measured in thirty-three prey and potential prey species of Weddell seals collected from the Ross Sea and McMurdo Sound regions of Antarctica. These same compounds were then measured in the plasma of twelve female Weddell seals over the lactation period at the Hutton Cliffs seal colony, McMurdo Sound in 2006. Time-depth recorders monitored seal dive activity over the same period. The data obtained from both NMR and LC-MS/MS assays showed that biomarkers in Antarctic species varied both in content and concentration. The compound homarine, which occurs primarily in cephalopods, is suitable for distinguishing between major food groups of known prey of Weddell seals (i.e., fishes versus cephalopods). DMSP, a compound that occurs primarily in fish common in McMurdo Sound (e.g., ... |
format |
Other/Unknown Material |
author |
Lenky, Crystal |
author_facet |
Lenky, Crystal |
author_sort |
Lenky, Crystal |
title |
Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
title_short |
Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
title_full |
Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
title_fullStr |
Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
title_full_unstemmed |
Foraging behaviour of female Weddell seals (Leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
title_sort |
foraging behaviour of female weddell seals (leptonychotes weddellii) during lactation: new insights from dietary biomarkers |
publisher |
University of Canterbury. Gateway Antarctica |
publishDate |
2012 |
url |
http://hdl.handle.net/10092/10367 https://doi.org/10.26021/6810 |
long_lat |
ENVELOPE(166.850,166.850,-77.733,-77.733) |
geographic |
Antarctic Hutton Cliffs McMurdo Sound Ross Sea Weddell |
geographic_facet |
Antarctic Hutton Cliffs McMurdo Sound Ross Sea Weddell |
genre |
Antarc* Antarctic Antarctica McMurdo Sound Ross Sea Weddell Seal Weddell Seals |
genre_facet |
Antarc* Antarctic Antarctica McMurdo Sound Ross Sea Weddell Seal Weddell Seals |
op_relation |
NZCU http://hdl.handle.net/10092/10367 http://dx.doi.org/10.26021/6810 |
op_rights |
Copyright Crystal Lenky https://canterbury.libguides.com/rights/theses |
op_doi |
https://doi.org/10.26021/6810 |
_version_ |
1766262709094973440 |