circumpolar sets of surveys
Sightings from the IDCR and SOWER austral summer surveys were analysed to provide abundance estimates for Antarctic (true) blue whales (Balaenoptera musculus intermedia) south of 60°S. The IDCR/SOWER ship-borne surveys have completely circled the Antarctic three times: 1978/79–1983/84 (CPI), 1985/86...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.527.1195 2023-05-15T13:42:41+02:00 circumpolar sets of surveys T. A. Branch The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.1195 http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-SH9.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.1195 http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-SH9.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-SH9.pdf text ftciteseerx 2016-01-08T10:24:19Z Sightings from the IDCR and SOWER austral summer surveys were analysed to provide abundance estimates for Antarctic (true) blue whales (Balaenoptera musculus intermedia) south of 60°S. The IDCR/SOWER ship-borne surveys have completely circled the Antarctic three times: 1978/79–1983/84 (CPI), 1985/86–1990/91 (CPII) and 1991/92–2003/04 (CPIII), covering strata totalling 64.3%, 79.5 % and 99.7 % of the ocean surface between the pack ice and 60°S. During the surveys, blue whales were only rarely sighted but were present around the Antarctic. Average sighting rates (schools per 1,000 km of primary search effort) were 0.24 (CPI), 0.36 (CPII) and 0.78 (CPIII). Respective circumpolar abundance estimates were 453 (CV=0.40), 559 (CV=0.47) and 2,280 (CV=0.36), with mid-years of 1980/81, 1987/88 and 1997/98. When adjusted simply for unsurveyed regions, the circumpolar rate of increase was 8.2 % (95 % CI 3.8–12.5%) per year, although they are still under 1 % of their pre-exploitation abundance. These abundance estimates are negatively biased because they exclude some Antarctic blue whales that are north of 60°S, and because a low number of blue whales on the trackline may be missed. Additionally, estimates may include a small proportion of pygmy blue whales, probably less than 1%. Abundance estimates were also provided for each IWC Management Area and for each individual survey, but these have high associated uncertainty. Text Antarc* Antarctic Balaenoptera musculus Unknown Antarctic Austral The Antarctic |
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ftciteseerx |
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English |
description |
Sightings from the IDCR and SOWER austral summer surveys were analysed to provide abundance estimates for Antarctic (true) blue whales (Balaenoptera musculus intermedia) south of 60°S. The IDCR/SOWER ship-borne surveys have completely circled the Antarctic three times: 1978/79–1983/84 (CPI), 1985/86–1990/91 (CPII) and 1991/92–2003/04 (CPIII), covering strata totalling 64.3%, 79.5 % and 99.7 % of the ocean surface between the pack ice and 60°S. During the surveys, blue whales were only rarely sighted but were present around the Antarctic. Average sighting rates (schools per 1,000 km of primary search effort) were 0.24 (CPI), 0.36 (CPII) and 0.78 (CPIII). Respective circumpolar abundance estimates were 453 (CV=0.40), 559 (CV=0.47) and 2,280 (CV=0.36), with mid-years of 1980/81, 1987/88 and 1997/98. When adjusted simply for unsurveyed regions, the circumpolar rate of increase was 8.2 % (95 % CI 3.8–12.5%) per year, although they are still under 1 % of their pre-exploitation abundance. These abundance estimates are negatively biased because they exclude some Antarctic blue whales that are north of 60°S, and because a low number of blue whales on the trackline may be missed. Additionally, estimates may include a small proportion of pygmy blue whales, probably less than 1%. Abundance estimates were also provided for each IWC Management Area and for each individual survey, but these have high associated uncertainty. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
T. A. Branch |
spellingShingle |
T. A. Branch circumpolar sets of surveys |
author_facet |
T. A. Branch |
author_sort |
T. A. Branch |
title |
circumpolar sets of surveys |
title_short |
circumpolar sets of surveys |
title_full |
circumpolar sets of surveys |
title_fullStr |
circumpolar sets of surveys |
title_full_unstemmed |
circumpolar sets of surveys |
title_sort |
circumpolar sets of surveys |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.1195 http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-SH9.pdf |
geographic |
Antarctic Austral The Antarctic |
geographic_facet |
Antarctic Austral The Antarctic |
genre |
Antarc* Antarctic Balaenoptera musculus |
genre_facet |
Antarc* Antarctic Balaenoptera musculus |
op_source |
http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-SH9.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.1195 http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-SH9.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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