Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery
Abstract This paper reports the results of using different hook style and bait type combinations on the catches of targeted, bycatch and discarded fishes in the Portuguese commercial longline fishery targeting swordfish ( Xiphias gladius ) in the South Atlantic Ocean. In total, 310 longline experime...
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crwiley:10.1002/aqc.2443 2024-09-15T18:36:29+00:00 Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery Amorim, Sérgio Santos, Miguel N. Coelho, Rui Fernandez‐Carvalho, Joana Programa PROMAR 2014 http://dx.doi.org/10.1002/aqc.2443 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faqc.2443 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aqc.2443 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Aquatic Conservation: Marine and Freshwater Ecosystems volume 25, issue 4, page 518-533 ISSN 1052-7613 1099-0755 journal-article 2014 crwiley https://doi.org/10.1002/aqc.2443 2024-08-06T04:17:01Z Abstract This paper reports the results of using different hook style and bait type combinations on the catches of targeted, bycatch and discarded fishes in the Portuguese commercial longline fishery targeting swordfish ( Xiphias gladius ) in the South Atlantic Ocean. In total, 310 longline experimental sets (446 400 hooks) were deployed between October 2008 and February 2012. Three different hook styles were tested; the traditional J‐hook (9/0) 10 o offset was compared with two 17/0 circle hooks (a non‐offset and a 10 o offset), and squid ( Illex spp.) bait was compared with mackerel ( Scomber spp.). Catch per unit effort (CPUE) was calculated for each fish species per fishing set and compared between the different hook style and bait type combinations. Results indicated that the effects of hook style and bait on the CPUEs were species‐specific. For example, swordfish (target species, Xiphias gladius ) CPUEs were higher with J‐hooks baited with squid, while for the blue shark (most important bycatch species, Prionace glauca ) the highest CPUEs were obtained with circle hooks baited with mackerel. For tuna ( Thunnus spp.) and marlin (blue, Makaira nigricans and white, Kajikia albida ) only the bait effect was significant, with higher catches with squid. For the discarded species, the proportions of alive vs dead specimens at the time of fishing gear retrieval were also species‐specific. The total retained catch value per unit of effort (VPUE) did not changed between the different hook and bait combinations, but these VPUEs are highly dependent on market fluctuations. Copyright © 2014 John Wiley & Sons, Ltd. Article in Journal/Newspaper South Atlantic Ocean Wiley Online Library Aquatic Conservation: Marine and Freshwater Ecosystems 25 4 518 533 |
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English |
description |
Abstract This paper reports the results of using different hook style and bait type combinations on the catches of targeted, bycatch and discarded fishes in the Portuguese commercial longline fishery targeting swordfish ( Xiphias gladius ) in the South Atlantic Ocean. In total, 310 longline experimental sets (446 400 hooks) were deployed between October 2008 and February 2012. Three different hook styles were tested; the traditional J‐hook (9/0) 10 o offset was compared with two 17/0 circle hooks (a non‐offset and a 10 o offset), and squid ( Illex spp.) bait was compared with mackerel ( Scomber spp.). Catch per unit effort (CPUE) was calculated for each fish species per fishing set and compared between the different hook style and bait type combinations. Results indicated that the effects of hook style and bait on the CPUEs were species‐specific. For example, swordfish (target species, Xiphias gladius ) CPUEs were higher with J‐hooks baited with squid, while for the blue shark (most important bycatch species, Prionace glauca ) the highest CPUEs were obtained with circle hooks baited with mackerel. For tuna ( Thunnus spp.) and marlin (blue, Makaira nigricans and white, Kajikia albida ) only the bait effect was significant, with higher catches with squid. For the discarded species, the proportions of alive vs dead specimens at the time of fishing gear retrieval were also species‐specific. The total retained catch value per unit of effort (VPUE) did not changed between the different hook and bait combinations, but these VPUEs are highly dependent on market fluctuations. Copyright © 2014 John Wiley & Sons, Ltd. |
author2 |
Programa PROMAR |
format |
Article in Journal/Newspaper |
author |
Amorim, Sérgio Santos, Miguel N. Coelho, Rui Fernandez‐Carvalho, Joana |
spellingShingle |
Amorim, Sérgio Santos, Miguel N. Coelho, Rui Fernandez‐Carvalho, Joana Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery |
author_facet |
Amorim, Sérgio Santos, Miguel N. Coelho, Rui Fernandez‐Carvalho, Joana |
author_sort |
Amorim, Sérgio |
title |
Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery |
title_short |
Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery |
title_full |
Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery |
title_fullStr |
Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery |
title_full_unstemmed |
Effects of 17/0 circle hooks and bait on fish catches in a Southern Atlantic swordfish longline fishery |
title_sort |
effects of 17/0 circle hooks and bait on fish catches in a southern atlantic swordfish longline fishery |
publisher |
Wiley |
publishDate |
2014 |
url |
http://dx.doi.org/10.1002/aqc.2443 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faqc.2443 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aqc.2443 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Aquatic Conservation: Marine and Freshwater Ecosystems volume 25, issue 4, page 518-533 ISSN 1052-7613 1099-0755 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/aqc.2443 |
container_title |
Aquatic Conservation: Marine and Freshwater Ecosystems |
container_volume |
25 |
container_issue |
4 |
container_start_page |
518 |
op_container_end_page |
533 |
_version_ |
1810480148936392704 |