Evidence for increases in Antarctic blue whales based on Bayesian modelling
Antarctic blue whales (Balaenoptera musculus intermedia) are the largest and formerly most abundant blue whale subspecies, but were hunted to near extinction last century. Estimated whaling mortality was unsustainable from 1928 to 1972 (except during 1942–1944), depleting them from 239,000 (95% inte...
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Online Access: | http://hdl.handle.net/11427/17262 https://open.uct.ac.za/bitstream/11427/17262/1/Branch_Evidence_for_increases_in_2004.pdf |
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ftunivcapetownir:oai:localhost:11427/17262 2023-05-15T13:32:17+02:00 Evidence for increases in Antarctic blue whales based on Bayesian modelling Branch, Trevor A Matsuoka, Koji Miyashita, Tomio 2004 application/pdf http://hdl.handle.net/11427/17262 https://open.uct.ac.za/bitstream/11427/17262/1/Branch_Evidence_for_increases_in_2004.pdf eng eng Wiley University of Cape Town Faculty of Science Marine Resource Assessment and Management Group http://hdl.handle.net/11427/17262 https://open.uct.ac.za/bitstream/11427/17262/1/Branch_Evidence_for_increases_in_2004.pdf Marine Mammal Science http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-7692 Antarctic blue whales true blue whales Balaenoptera musculus intermedia Journal Article 2004 ftunivcapetownir https://doi.org/10.1111/(ISSN)1748-7692 2022-09-13T05:54:02Z Antarctic blue whales (Balaenoptera musculus intermedia) are the largest and formerly most abundant blue whale subspecies, but were hunted to near extinction last century. Estimated whaling mortality was unsustainable from 1928 to 1972 (except during 1942–1944), depleting them from 239,000 (95% interval 202,000–311,000) to a low of 360 (150–840) in 1973. Obtaining statistical evidence for subsequent increases has proved difficult due to their scarcity. We fitted Bayesian models to three sighting series (1968–2001), constraining maximum rates of increase to 12% per annum. These models indicated that Antarctic blue whales are increasing at a mean rate of 7.3% per annum (1.4%–11.6%). Informative priors based on blue whale biology (4.3%, SD = 1.9%) and a Bayesian hierarchical meta-analysis of increase rates in other blue whale populations (−3%, SD = 11.6%), suggest plausible increase rates are lower (although the latter has wide intervals), but a meta-analysis of other mysticetes obtains similar rates of increase (6.7%, SD = 4.0%). Possible biases affecting the input abundance estimates are discussed. Although Antarctic blue whales appear to have been increasing since Sovier illegal whaling ended in 1972, they still need to be protected-their estimated 1996 population size, 1,700 (860–2,900), was just 0.7% (0.3%–1.3%) of the pre-exploitation level. Article in Journal/Newspaper Antarc* Antarctic Balaenoptera musculus Blue whale University of Cape Town: OpenUCT Antarctic Marine Mammal Science |
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Open Polar |
collection |
University of Cape Town: OpenUCT |
op_collection_id |
ftunivcapetownir |
language |
English |
topic |
Antarctic blue whales true blue whales Balaenoptera musculus intermedia |
spellingShingle |
Antarctic blue whales true blue whales Balaenoptera musculus intermedia Branch, Trevor A Matsuoka, Koji Miyashita, Tomio Evidence for increases in Antarctic blue whales based on Bayesian modelling |
topic_facet |
Antarctic blue whales true blue whales Balaenoptera musculus intermedia |
description |
Antarctic blue whales (Balaenoptera musculus intermedia) are the largest and formerly most abundant blue whale subspecies, but were hunted to near extinction last century. Estimated whaling mortality was unsustainable from 1928 to 1972 (except during 1942–1944), depleting them from 239,000 (95% interval 202,000–311,000) to a low of 360 (150–840) in 1973. Obtaining statistical evidence for subsequent increases has proved difficult due to their scarcity. We fitted Bayesian models to three sighting series (1968–2001), constraining maximum rates of increase to 12% per annum. These models indicated that Antarctic blue whales are increasing at a mean rate of 7.3% per annum (1.4%–11.6%). Informative priors based on blue whale biology (4.3%, SD = 1.9%) and a Bayesian hierarchical meta-analysis of increase rates in other blue whale populations (−3%, SD = 11.6%), suggest plausible increase rates are lower (although the latter has wide intervals), but a meta-analysis of other mysticetes obtains similar rates of increase (6.7%, SD = 4.0%). Possible biases affecting the input abundance estimates are discussed. Although Antarctic blue whales appear to have been increasing since Sovier illegal whaling ended in 1972, they still need to be protected-their estimated 1996 population size, 1,700 (860–2,900), was just 0.7% (0.3%–1.3%) of the pre-exploitation level. |
format |
Article in Journal/Newspaper |
author |
Branch, Trevor A Matsuoka, Koji Miyashita, Tomio |
author_facet |
Branch, Trevor A Matsuoka, Koji Miyashita, Tomio |
author_sort |
Branch, Trevor A |
title |
Evidence for increases in Antarctic blue whales based on Bayesian modelling |
title_short |
Evidence for increases in Antarctic blue whales based on Bayesian modelling |
title_full |
Evidence for increases in Antarctic blue whales based on Bayesian modelling |
title_fullStr |
Evidence for increases in Antarctic blue whales based on Bayesian modelling |
title_full_unstemmed |
Evidence for increases in Antarctic blue whales based on Bayesian modelling |
title_sort |
evidence for increases in antarctic blue whales based on bayesian modelling |
publisher |
Wiley |
publishDate |
2004 |
url |
http://hdl.handle.net/11427/17262 https://open.uct.ac.za/bitstream/11427/17262/1/Branch_Evidence_for_increases_in_2004.pdf |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Balaenoptera musculus Blue whale |
genre_facet |
Antarc* Antarctic Balaenoptera musculus Blue whale |
op_source |
Marine Mammal Science http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-7692 |
op_relation |
http://hdl.handle.net/11427/17262 https://open.uct.ac.za/bitstream/11427/17262/1/Branch_Evidence_for_increases_in_2004.pdf |
op_doi |
https://doi.org/10.1111/(ISSN)1748-7692 |
container_title |
Marine Mammal Science |
_version_ |
1766025661013557248 |