Abundance of blue whales off Chile from the 1997/98 SOWER survey
The 1997/98 SOWER survey in Chile searched the region from 18°30′S to 38°S. Although the primary intention of the surveys was to maximize blue whale encounters, survey coverage was sufficient to estimate abundance using line transect methods. The baseline abundance estimate, excluding transit legs,...
Main Authors: | , , |
---|---|
Format: | Report |
Language: | English |
Published: |
University of Cape Town
2007
|
Subjects: | |
Online Access: | http://hdl.handle.net/11427/17641 https://open.uct.ac.za/bitstream/11427/17641/1/Branch_Abundance_blue_whales_off_2007.pdf |
id |
ftunivcapetownir:oai:localhost:11427/17641 |
---|---|
record_format |
openpolar |
spelling |
ftunivcapetownir:oai:localhost:11427/17641 2023-05-15T15:45:11+02:00 Abundance of blue whales off Chile from the 1997/98 SOWER survey Branch, Trevor A Zerbini, Alexandre N Findlay, Ken 2007 application/pdf http://hdl.handle.net/11427/17641 https://open.uct.ac.za/bitstream/11427/17641/1/Branch_Abundance_blue_whales_off_2007.pdf eng eng University of Cape Town Faculty of Science Marine Resource Assessment and Management Group http://hdl.handle.net/11427/17641 https://open.uct.ac.za/bitstream/11427/17641/1/Branch_Abundance_blue_whales_off_2007.pdf blue whales Chile 1997/98 SOWER survey Working Paper 2007 ftunivcapetownir 2022-09-13T05:52:29Z The 1997/98 SOWER survey in Chile searched the region from 18°30′S to 38°S. Although the primary intention of the surveys was to maximize blue whale encounters, survey coverage was sufficient to estimate abundance using line transect methods. The baseline abundance estimate, excluding transit legs, was 452 (CV = 0.56, 95% CI: 160–1300). This abundance estimate is negatively biased because inshore regions including Chiloé Island and the Gulf of Corcovado, where blue whales are now known to aggregate, were outside the survey area. If it is conservatively assumed that the baseline estimate applied to the entire population, then the population was at a minimum of 7–23% of pre-exploitation levels in 1997. Report Blue whale University of Cape Town: OpenUCT Chiloé ENVELOPE(-63.983,-63.983,-65.517,-65.517) |
institution |
Open Polar |
collection |
University of Cape Town: OpenUCT |
op_collection_id |
ftunivcapetownir |
language |
English |
topic |
blue whales Chile 1997/98 SOWER survey |
spellingShingle |
blue whales Chile 1997/98 SOWER survey Branch, Trevor A Zerbini, Alexandre N Findlay, Ken Abundance of blue whales off Chile from the 1997/98 SOWER survey |
topic_facet |
blue whales Chile 1997/98 SOWER survey |
description |
The 1997/98 SOWER survey in Chile searched the region from 18°30′S to 38°S. Although the primary intention of the surveys was to maximize blue whale encounters, survey coverage was sufficient to estimate abundance using line transect methods. The baseline abundance estimate, excluding transit legs, was 452 (CV = 0.56, 95% CI: 160–1300). This abundance estimate is negatively biased because inshore regions including Chiloé Island and the Gulf of Corcovado, where blue whales are now known to aggregate, were outside the survey area. If it is conservatively assumed that the baseline estimate applied to the entire population, then the population was at a minimum of 7–23% of pre-exploitation levels in 1997. |
format |
Report |
author |
Branch, Trevor A Zerbini, Alexandre N Findlay, Ken |
author_facet |
Branch, Trevor A Zerbini, Alexandre N Findlay, Ken |
author_sort |
Branch, Trevor A |
title |
Abundance of blue whales off Chile from the 1997/98 SOWER survey |
title_short |
Abundance of blue whales off Chile from the 1997/98 SOWER survey |
title_full |
Abundance of blue whales off Chile from the 1997/98 SOWER survey |
title_fullStr |
Abundance of blue whales off Chile from the 1997/98 SOWER survey |
title_full_unstemmed |
Abundance of blue whales off Chile from the 1997/98 SOWER survey |
title_sort |
abundance of blue whales off chile from the 1997/98 sower survey |
publisher |
University of Cape Town |
publishDate |
2007 |
url |
http://hdl.handle.net/11427/17641 https://open.uct.ac.za/bitstream/11427/17641/1/Branch_Abundance_blue_whales_off_2007.pdf |
long_lat |
ENVELOPE(-63.983,-63.983,-65.517,-65.517) |
geographic |
Chiloé |
geographic_facet |
Chiloé |
genre |
Blue whale |
genre_facet |
Blue whale |
op_relation |
http://hdl.handle.net/11427/17641 https://open.uct.ac.za/bitstream/11427/17641/1/Branch_Abundance_blue_whales_off_2007.pdf |
_version_ |
1766379529059696640 |