Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study.
The threat of population declines caused by pelagic longline fisheries in the Atlantic has increased the concern to find strategies that minimize the bycatch and mortality of non-target marine animals. Gear modification, such as the use of circle hooks instead of conventional J-hooks, has been ident...
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ftdoajarticles:oai:doaj.org/article:157d0a240d2b44aaae2b67301bd357be 2023-11-12T04:22:40+01:00 Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. Françoise D Lima Hugo Parra Rita B Alves Marco A R Santos Karen A Bjorndal Alan B Bolten Frederic Vandeperre 2023-01-01T00:00:00Z https://doi.org/10.1371/journal.pone.0292727 https://doaj.org/article/157d0a240d2b44aaae2b67301bd357be EN eng Public Library of Science (PLoS) https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0292727&type=printable https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0292727 https://doaj.org/article/157d0a240d2b44aaae2b67301bd357be PLoS ONE, Vol 18, Iss 10, p e0292727 (2023) Medicine R Science Q article 2023 ftdoajarticles https://doi.org/10.1371/journal.pone.0292727 2023-10-29T00:38:46Z The threat of population declines caused by pelagic longline fisheries in the Atlantic has increased the concern to find strategies that minimize the bycatch and mortality of non-target marine animals. Gear modification, such as the use of circle hooks instead of conventional J-hooks, has been identified as an effective bycatch reduction strategy in different pelagic longline fisheries around the world. This study aimed to verify the effectiveness of the use of circle hooks by quantifying catch rates, relative size selectivity, and anatomical hooking position for the most common target species (swordfish, Xiphias gladius, and blue shark, Prionace glauca), and some bycatch species (loggerhead sea turtles, Caretta caretta, and shortfin mako, Isurus oxyrinchus) caught by the Azorean longline fishing fleet. The trial was conducted for five consecutive years (2000-2004) using eight different types of hooks. In general, the blue shark catches using circle hooks were significantly higher compared to J (Mustad 9/0). The circle hooks also showed high probabilities of catching juvenile blue sharks. Conversely, the circle hooks were efficient in reducing the loggerhead sea turtle bycatch and were related to fewer catches of small sea turtle individuals. The use of circle hooks was also associated with reduced swordfish catches compared to J (Mustad 9/0), and the effect of hook types on length at capture was only significant for Circle (L. & P. 18/0-CLP18) and Ringed Tuna (RT). No significant differences were observed comparing hook type to either catch rates or size selectivity for shortfin mako. Additionally, circle hooks were more likely to lodge in the mouth than in deeper anatomical positions, when compared to J (Mustad 9/0), for the four species analysed. The present study demonstrated that the use of circle hooks could mitigate the impact of the pelagic longline fisheries in the Azores by decreasing the bycatch of sea turtles and reducing animal injuries caused by deep hooking. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles PLOS ONE 18 10 e0292727 |
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ftdoajarticles |
language |
English |
topic |
Medicine R Science Q |
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Medicine R Science Q Françoise D Lima Hugo Parra Rita B Alves Marco A R Santos Karen A Bjorndal Alan B Bolten Frederic Vandeperre Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. |
topic_facet |
Medicine R Science Q |
description |
The threat of population declines caused by pelagic longline fisheries in the Atlantic has increased the concern to find strategies that minimize the bycatch and mortality of non-target marine animals. Gear modification, such as the use of circle hooks instead of conventional J-hooks, has been identified as an effective bycatch reduction strategy in different pelagic longline fisheries around the world. This study aimed to verify the effectiveness of the use of circle hooks by quantifying catch rates, relative size selectivity, and anatomical hooking position for the most common target species (swordfish, Xiphias gladius, and blue shark, Prionace glauca), and some bycatch species (loggerhead sea turtles, Caretta caretta, and shortfin mako, Isurus oxyrinchus) caught by the Azorean longline fishing fleet. The trial was conducted for five consecutive years (2000-2004) using eight different types of hooks. In general, the blue shark catches using circle hooks were significantly higher compared to J (Mustad 9/0). The circle hooks also showed high probabilities of catching juvenile blue sharks. Conversely, the circle hooks were efficient in reducing the loggerhead sea turtle bycatch and were related to fewer catches of small sea turtle individuals. The use of circle hooks was also associated with reduced swordfish catches compared to J (Mustad 9/0), and the effect of hook types on length at capture was only significant for Circle (L. & P. 18/0-CLP18) and Ringed Tuna (RT). No significant differences were observed comparing hook type to either catch rates or size selectivity for shortfin mako. Additionally, circle hooks were more likely to lodge in the mouth than in deeper anatomical positions, when compared to J (Mustad 9/0), for the four species analysed. The present study demonstrated that the use of circle hooks could mitigate the impact of the pelagic longline fisheries in the Azores by decreasing the bycatch of sea turtles and reducing animal injuries caused by deep hooking. |
format |
Article in Journal/Newspaper |
author |
Françoise D Lima Hugo Parra Rita B Alves Marco A R Santos Karen A Bjorndal Alan B Bolten Frederic Vandeperre |
author_facet |
Françoise D Lima Hugo Parra Rita B Alves Marco A R Santos Karen A Bjorndal Alan B Bolten Frederic Vandeperre |
author_sort |
Françoise D Lima |
title |
Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. |
title_short |
Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. |
title_full |
Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. |
title_fullStr |
Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. |
title_full_unstemmed |
Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study. |
title_sort |
effects of gear modifications in a north atlantic pelagic longline fishery: a multiyear study. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2023 |
url |
https://doi.org/10.1371/journal.pone.0292727 https://doaj.org/article/157d0a240d2b44aaae2b67301bd357be |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
PLoS ONE, Vol 18, Iss 10, p e0292727 (2023) |
op_relation |
https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0292727&type=printable https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0292727 https://doaj.org/article/157d0a240d2b44aaae2b67301bd357be |
op_doi |
https://doi.org/10.1371/journal.pone.0292727 |
container_title |
PLOS ONE |
container_volume |
18 |
container_issue |
10 |
container_start_page |
e0292727 |
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1782337640568193024 |