Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf.
The North Atlantic blue whale was depleted by modern whaling and it is still considered to be highly endangered. Despite its protection in 1954, catches continued in the South European Atlantic Shelf (SEAS) region and immediately adjacent waters until 1979. We compiled catches and investigate abunda...
Published in: | Scientific Reports |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature Publishing Group
2022
|
Subjects: | |
Online Access: | http://hdl.handle.net/2445/190356 |
id |
ftubarcepubl:oai:diposit.ub.edu:2445/190356 |
---|---|
record_format |
openpolar |
spelling |
ftubarcepubl:oai:diposit.ub.edu:2445/190356 2024-02-11T10:02:24+01:00 Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. Aguilar, Àlex Borrell Thió, Assumpció 2022-03-31 12 p. application/pdf http://hdl.handle.net/2445/190356 eng eng Nature Publishing Group Reproducció del document publicat a: https://doi.org/10.1038/s41598-022-09570-6 Scientific Reports, 2022, vol. 12, num. 5491, p. 1-12 Articles publicats en revistes (Biologia Evolutiva, Ecologia i Ciències Ambientals) https://doi.org/10.1038/s41598-022-09570-6 2045-2322 http://hdl.handle.net/2445/190356 726302 cc-by (c) Aguilar, Àlex et al., 2022 https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Balenes Plataforma continental Europa del Sud Atlàntic Oceà Caça Whales Continental shelf Southern Europe Atlantic Ocean Hunting info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2022 ftubarcepubl https://doi.org/10.1038/s41598-022-09570-6 2024-01-24T01:18:46Z The North Atlantic blue whale was depleted by modern whaling and it is still considered to be highly endangered. Despite its protection in 1954, catches continued in the South European Atlantic Shelf (SEAS) region and immediately adjacent waters until 1979. We compiled catches and investigate abundance trends in the region using original data from whaling (1921-1985) and scientific surveys around the last years of exploitation (1981-1987). The struck and lost rate was estimated at 3.2% for sperm whales and 2.3% for baleen whales. The compiled records include 60 catches, with an additional 1-2 blue whales likely struck and lost. From these, 29 individuals had been correctly reported as blue whales but 31 were mislabelled as fin whales. After correcting for loss rates, the number of blue whales killed in the region was estimated at 61 in 55 years (1.12 individuals/year). The data from the 1950s shows some oversized fin whales but it is unclear whether they are due to an incorrect reporting of species or to incorrect measurements, so it cannot be discarded that the actual number of blue whales caught was slightly higher than estimated. Mean body length of reported blue whales was lower than in higher latitudes of the North Atlantic, probably reflecting geographical stratification with higher proportion of immatures in the SEAS. The ratio between catches or sightings of blue whales and those of fin whales was 5.9% in the southern part of the SEAS previous to exploitation, it declined to 0.02- 0.18% in the 1920s, and increased thereafter up to 1.6% in the 1980-1990s. Taking as reference the population size of fin whales in the SEAS, that of blue whales at the end of the 1980s can be guessed to be at ca337-497 individuals. Considering accepted population estimates in other areas as well as the observed rates of increase, current abundance is thought to be over a thousand whales in the SEAs and at in the order of 4000-5000 individuals for the whole eastern North Atlantic basin. Article in Journal/Newspaper baleen whales Blue whale North Atlantic Dipòsit Digital de la Universitat de Barcelona Scientific Reports 12 1 |
institution |
Open Polar |
collection |
Dipòsit Digital de la Universitat de Barcelona |
op_collection_id |
ftubarcepubl |
language |
English |
topic |
Balenes Plataforma continental Europa del Sud Atlàntic Oceà Caça Whales Continental shelf Southern Europe Atlantic Ocean Hunting |
spellingShingle |
Balenes Plataforma continental Europa del Sud Atlàntic Oceà Caça Whales Continental shelf Southern Europe Atlantic Ocean Hunting Aguilar, Àlex Borrell Thió, Assumpció Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. |
topic_facet |
Balenes Plataforma continental Europa del Sud Atlàntic Oceà Caça Whales Continental shelf Southern Europe Atlantic Ocean Hunting |
description |
The North Atlantic blue whale was depleted by modern whaling and it is still considered to be highly endangered. Despite its protection in 1954, catches continued in the South European Atlantic Shelf (SEAS) region and immediately adjacent waters until 1979. We compiled catches and investigate abundance trends in the region using original data from whaling (1921-1985) and scientific surveys around the last years of exploitation (1981-1987). The struck and lost rate was estimated at 3.2% for sperm whales and 2.3% for baleen whales. The compiled records include 60 catches, with an additional 1-2 blue whales likely struck and lost. From these, 29 individuals had been correctly reported as blue whales but 31 were mislabelled as fin whales. After correcting for loss rates, the number of blue whales killed in the region was estimated at 61 in 55 years (1.12 individuals/year). The data from the 1950s shows some oversized fin whales but it is unclear whether they are due to an incorrect reporting of species or to incorrect measurements, so it cannot be discarded that the actual number of blue whales caught was slightly higher than estimated. Mean body length of reported blue whales was lower than in higher latitudes of the North Atlantic, probably reflecting geographical stratification with higher proportion of immatures in the SEAS. The ratio between catches or sightings of blue whales and those of fin whales was 5.9% in the southern part of the SEAS previous to exploitation, it declined to 0.02- 0.18% in the 1920s, and increased thereafter up to 1.6% in the 1980-1990s. Taking as reference the population size of fin whales in the SEAS, that of blue whales at the end of the 1980s can be guessed to be at ca337-497 individuals. Considering accepted population estimates in other areas as well as the observed rates of increase, current abundance is thought to be over a thousand whales in the SEAs and at in the order of 4000-5000 individuals for the whole eastern North Atlantic basin. |
format |
Article in Journal/Newspaper |
author |
Aguilar, Àlex Borrell Thió, Assumpció |
author_facet |
Aguilar, Àlex Borrell Thió, Assumpció |
author_sort |
Aguilar, Àlex |
title |
Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. |
title_short |
Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. |
title_full |
Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. |
title_fullStr |
Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. |
title_full_unstemmed |
Unreported catches, impact of whaling and current status of blue whales in the South European Atlantic Shelf. |
title_sort |
unreported catches, impact of whaling and current status of blue whales in the south european atlantic shelf. |
publisher |
Nature Publishing Group |
publishDate |
2022 |
url |
http://hdl.handle.net/2445/190356 |
genre |
baleen whales Blue whale North Atlantic |
genre_facet |
baleen whales Blue whale North Atlantic |
op_relation |
Reproducció del document publicat a: https://doi.org/10.1038/s41598-022-09570-6 Scientific Reports, 2022, vol. 12, num. 5491, p. 1-12 Articles publicats en revistes (Biologia Evolutiva, Ecologia i Ciències Ambientals) https://doi.org/10.1038/s41598-022-09570-6 2045-2322 http://hdl.handle.net/2445/190356 726302 |
op_rights |
cc-by (c) Aguilar, Àlex et al., 2022 https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1038/s41598-022-09570-6 |
container_title |
Scientific Reports |
container_volume |
12 |
container_issue |
1 |
_version_ |
1790598330826358784 |