A comparison of image and observer based aerial surveys of narwhal
Abstract From 25 to 30 August 2014 a double‐observer line‐transect survey was conducted over Melville Bay, home to one of two summering populations of narwhal ( Monodon monoceros ) off West Greenland. A total of 1,932 linear kilometers was surveyed along 33 transects. In addition to using observers,...
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crwiley:10.1111/mms.12586 2024-09-09T19:43:24+00:00 A comparison of image and observer based aerial surveys of narwhal Bröker, Koen C. A. Hansen, Rikke G. Leonard, Kathleen E. Koski, William R. Heide‐Jørgensen, Mads Peter Greenland Bureau of Minerals and Petroleum Shell Alaska Shell Greenland A/S 2019 http://dx.doi.org/10.1111/mms.12586 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmms.12586 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12586 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/mms.12586 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Marine Mammal Science volume 35, issue 4, page 1253-1279 ISSN 0824-0469 1748-7692 journal-article 2019 crwiley https://doi.org/10.1111/mms.12586 2024-07-30T04:22:26Z Abstract From 25 to 30 August 2014 a double‐observer line‐transect survey was conducted over Melville Bay, home to one of two summering populations of narwhal ( Monodon monoceros ) off West Greenland. A total of 1,932 linear kilometers was surveyed along 33 transects. In addition to using observers, the aircraft was equipped with two oblique cameras to capture a comparable data set. Analysts reviewed the images for narwhal sightings, which were then matched to the observer sightings. The objectives of the study were to determine advantages and disadvantages of the detection capabilities of both methodologies, and to conduct a comparative analysis of population abundance estimates. Correcting for the truncated detection distance of the images (500 m), the image analysts recorded more sightings (62) and a lower mean group size (2.2) compared to aerial observers (36 and 3.5, respectively), resulting in comparable numbers of individuals detected by both platforms (135 vs . 126). The abundance estimate based on the image sightings was 2,536 (CV = 0.51, 95% CI: 1,003–6,406), which was not significantly different from the aerial observers estimate of 2,596 individuals (CV = 0.51; 95% CI: 961–7,008). This study supports the potential of using UAS for marine mammal abundance studies. Article in Journal/Newspaper Greenland Monodon monoceros narwhal* Wiley Online Library Greenland Marine Mammal Science 35 4 1253 1279 |
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Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract From 25 to 30 August 2014 a double‐observer line‐transect survey was conducted over Melville Bay, home to one of two summering populations of narwhal ( Monodon monoceros ) off West Greenland. A total of 1,932 linear kilometers was surveyed along 33 transects. In addition to using observers, the aircraft was equipped with two oblique cameras to capture a comparable data set. Analysts reviewed the images for narwhal sightings, which were then matched to the observer sightings. The objectives of the study were to determine advantages and disadvantages of the detection capabilities of both methodologies, and to conduct a comparative analysis of population abundance estimates. Correcting for the truncated detection distance of the images (500 m), the image analysts recorded more sightings (62) and a lower mean group size (2.2) compared to aerial observers (36 and 3.5, respectively), resulting in comparable numbers of individuals detected by both platforms (135 vs . 126). The abundance estimate based on the image sightings was 2,536 (CV = 0.51, 95% CI: 1,003–6,406), which was not significantly different from the aerial observers estimate of 2,596 individuals (CV = 0.51; 95% CI: 961–7,008). This study supports the potential of using UAS for marine mammal abundance studies. |
author2 |
Greenland Bureau of Minerals and Petroleum Shell Alaska Shell Greenland A/S |
format |
Article in Journal/Newspaper |
author |
Bröker, Koen C. A. Hansen, Rikke G. Leonard, Kathleen E. Koski, William R. Heide‐Jørgensen, Mads Peter |
spellingShingle |
Bröker, Koen C. A. Hansen, Rikke G. Leonard, Kathleen E. Koski, William R. Heide‐Jørgensen, Mads Peter A comparison of image and observer based aerial surveys of narwhal |
author_facet |
Bröker, Koen C. A. Hansen, Rikke G. Leonard, Kathleen E. Koski, William R. Heide‐Jørgensen, Mads Peter |
author_sort |
Bröker, Koen C. A. |
title |
A comparison of image and observer based aerial surveys of narwhal |
title_short |
A comparison of image and observer based aerial surveys of narwhal |
title_full |
A comparison of image and observer based aerial surveys of narwhal |
title_fullStr |
A comparison of image and observer based aerial surveys of narwhal |
title_full_unstemmed |
A comparison of image and observer based aerial surveys of narwhal |
title_sort |
comparison of image and observer based aerial surveys of narwhal |
publisher |
Wiley |
publishDate |
2019 |
url |
http://dx.doi.org/10.1111/mms.12586 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmms.12586 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12586 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/mms.12586 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Monodon monoceros narwhal* |
genre_facet |
Greenland Monodon monoceros narwhal* |
op_source |
Marine Mammal Science volume 35, issue 4, page 1253-1279 ISSN 0824-0469 1748-7692 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1111/mms.12586 |
container_title |
Marine Mammal Science |
container_volume |
35 |
container_issue |
4 |
container_start_page |
1253 |
op_container_end_page |
1279 |
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1809912749240614912 |