Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods
The method traditionally used to estimate pack-ice seal abundance employs sighting surveys from ships or ail-craft to estimate the number of seals hauled out oil the ice, combined with studies of haul-out behaviour to estimate the proportion of time spent on the ice. Application of this approach has...
Published in: | Deep Sea Research Part I: Oceanographic Research Papers |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2008
|
Subjects: | |
Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/uncommon-or-cryptic-challenges-in-estimating-leopard-seal-abundance-by-conventional-but-stateoftheart-methods(ab69c352-5c41-4fe4-8eb6-9a4aa0d91f06).html https://doi.org/10.1016/j.dsr.2008.01.005 http://www.scopus.com/inward/record.url?scp=41549144279&partnerID=8YFLogxK |
id |
ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/ab69c352-5c41-4fe4-8eb6-9a4aa0d91f06 |
---|---|
record_format |
openpolar |
spelling |
ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/ab69c352-5c41-4fe4-8eb6-9a4aa0d91f06 2023-05-15T13:39:30+02:00 Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods Southwell, Colin Paxton, Charles G. M. Borchers, David Boveng, Peter Rogers, Tracey de la Mare, William K. 2008-04 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/uncommon-or-cryptic-challenges-in-estimating-leopard-seal-abundance-by-conventional-but-stateoftheart-methods(ab69c352-5c41-4fe4-8eb6-9a4aa0d91f06).html https://doi.org/10.1016/j.dsr.2008.01.005 http://www.scopus.com/inward/record.url?scp=41549144279&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Southwell , C , Paxton , C G M , Borchers , D , Boveng , P , Rogers , T & de la Mare , W K 2008 , ' Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods ' , Deep Sea Research Part I: Oceanographic Research Papers , vol. 55 , pp. 519-531 . https://doi.org/10.1016/j.dsr.2008.01.005 abundance distribution East Antarctica haul-out model-based inference leopard seal pack-ice HYDRURGA-LEPTONYX LOBODON-CARCINOPHAGUS WINTER DISPERSAL PRYDZ BAY BEHAVIOR article 2008 ftunstandrewcris https://doi.org/10.1016/j.dsr.2008.01.005 2022-07-21T06:59:49Z The method traditionally used to estimate pack-ice seal abundance employs sighting surveys from ships or ail-craft to estimate the number of seals hauled out oil the ice, combined with studies of haul-out behaviour to estimate the proportion of time spent on the ice. Application of this approach has been improved in recent times by developments in survey methodology and satellite technology that theoretically allow biases in the estimation of hauled-out abundance and haul-out behaviour to be accounted for that previously could not be addressed. A survey using these conventional but state-of-the-art methods was undertaken in the summer of 1999/2000 off east Antarctica between longitudes 64 degrees E and 150 degrees E to estimate the abundance of leopard (Hydrurga leptonyx) and other pack-ice seal species. Because they are either uncommon or very cryptic, very few leopard seals were encountered despite a large survey effort. This presented challenges in both application of the methods and analysis of the data. Abundance estimates were derived using a number of plausible predictive models. The model considered as the most reliable returned best estimates of 7300 and 12,100 for definite and definite plus probable leopard seal sightings, respectively, with 95%, confidence intervals of 3700-14,500 and 7100-23,400. These estimates are likely to be negatively biased and should be treated as minimum estimates only. (c) 2008 Elsevier Ltd. All rights reserved. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Hydrurga leptonyx Leopard Seal Leopard Seals Lobodon carcinophagus Prydz Bay University of St Andrews: Research Portal East Antarctica Hydrurga ENVELOPE(-61.626,-61.626,-64.145,-64.145) Prydz Bay Deep Sea Research Part I: Oceanographic Research Papers 55 4 519 531 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
abundance distribution East Antarctica haul-out model-based inference leopard seal pack-ice HYDRURGA-LEPTONYX LOBODON-CARCINOPHAGUS WINTER DISPERSAL PRYDZ BAY BEHAVIOR |
spellingShingle |
abundance distribution East Antarctica haul-out model-based inference leopard seal pack-ice HYDRURGA-LEPTONYX LOBODON-CARCINOPHAGUS WINTER DISPERSAL PRYDZ BAY BEHAVIOR Southwell, Colin Paxton, Charles G. M. Borchers, David Boveng, Peter Rogers, Tracey de la Mare, William K. Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
topic_facet |
abundance distribution East Antarctica haul-out model-based inference leopard seal pack-ice HYDRURGA-LEPTONYX LOBODON-CARCINOPHAGUS WINTER DISPERSAL PRYDZ BAY BEHAVIOR |
description |
The method traditionally used to estimate pack-ice seal abundance employs sighting surveys from ships or ail-craft to estimate the number of seals hauled out oil the ice, combined with studies of haul-out behaviour to estimate the proportion of time spent on the ice. Application of this approach has been improved in recent times by developments in survey methodology and satellite technology that theoretically allow biases in the estimation of hauled-out abundance and haul-out behaviour to be accounted for that previously could not be addressed. A survey using these conventional but state-of-the-art methods was undertaken in the summer of 1999/2000 off east Antarctica between longitudes 64 degrees E and 150 degrees E to estimate the abundance of leopard (Hydrurga leptonyx) and other pack-ice seal species. Because they are either uncommon or very cryptic, very few leopard seals were encountered despite a large survey effort. This presented challenges in both application of the methods and analysis of the data. Abundance estimates were derived using a number of plausible predictive models. The model considered as the most reliable returned best estimates of 7300 and 12,100 for definite and definite plus probable leopard seal sightings, respectively, with 95%, confidence intervals of 3700-14,500 and 7100-23,400. These estimates are likely to be negatively biased and should be treated as minimum estimates only. (c) 2008 Elsevier Ltd. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Southwell, Colin Paxton, Charles G. M. Borchers, David Boveng, Peter Rogers, Tracey de la Mare, William K. |
author_facet |
Southwell, Colin Paxton, Charles G. M. Borchers, David Boveng, Peter Rogers, Tracey de la Mare, William K. |
author_sort |
Southwell, Colin |
title |
Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
title_short |
Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
title_full |
Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
title_fullStr |
Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
title_full_unstemmed |
Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
title_sort |
uncommon or cryptic? challenges in estimating leopard seal abundance by conventional but state-of-the-art methods |
publishDate |
2008 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/uncommon-or-cryptic-challenges-in-estimating-leopard-seal-abundance-by-conventional-but-stateoftheart-methods(ab69c352-5c41-4fe4-8eb6-9a4aa0d91f06).html https://doi.org/10.1016/j.dsr.2008.01.005 http://www.scopus.com/inward/record.url?scp=41549144279&partnerID=8YFLogxK |
long_lat |
ENVELOPE(-61.626,-61.626,-64.145,-64.145) |
geographic |
East Antarctica Hydrurga Prydz Bay |
geographic_facet |
East Antarctica Hydrurga Prydz Bay |
genre |
Antarc* Antarctica East Antarctica Hydrurga leptonyx Leopard Seal Leopard Seals Lobodon carcinophagus Prydz Bay |
genre_facet |
Antarc* Antarctica East Antarctica Hydrurga leptonyx Leopard Seal Leopard Seals Lobodon carcinophagus Prydz Bay |
op_source |
Southwell , C , Paxton , C G M , Borchers , D , Boveng , P , Rogers , T & de la Mare , W K 2008 , ' Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods ' , Deep Sea Research Part I: Oceanographic Research Papers , vol. 55 , pp. 519-531 . https://doi.org/10.1016/j.dsr.2008.01.005 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.dsr.2008.01.005 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
55 |
container_issue |
4 |
container_start_page |
519 |
op_container_end_page |
531 |
_version_ |
1766119736601477120 |