Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean
Three types of hooks and baits were tested on two swordfish longliners over a period of 480 days at sea in five zones of the North and South Atlantic Ocean. Nominal CPUE data would suggest that the overall catch rates in weight of the fish species in general were reduced with the alternate hooks and...
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ftcsic:oai:digital.csic.es:10261/322233 2024-02-11T10:08:38+01:00 Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean Mejuto-García, Jaime García-Cortés, Blanca Ramos-Cartelle, Ana Madrid (España) 2008 http://hdl.handle.net/10508/3457 http://hdl.handle.net/10261/322233 unknown Centro Oceanográfico de A Coruña VoR Grupo de especies de ICCAT. (23/09/2007 - 25/09/2007. Madrid, España). 2008. Col. Vol. Sci. Pap. ICCAT, 60(6) http://hdl.handle.net/10508/3457 http://hdl.handle.net/10261/322233 488 open Pesquerías Centro Oceanográfico de A Coruña Longline CPUE hook bait swordfish sea turtles sea birds working paper 2008 ftcsic 2024-01-16T11:46:51Z Three types of hooks and baits were tested on two swordfish longliners over a period of 480 days at sea in five zones of the North and South Atlantic Ocean. Nominal CPUE data would suggest that the overall catch rates in weight of the fish species in general were reduced with the alternate hooks and baits tested. Overall rates (+7% and –8%) and (+3% and –11%) were found for the swordfish and blue shark, respectively in relation to the hook and bait combination of reference. The shortfin mako exhibited substantial decreases (–9% and –61%). For the billfish group, however, the all rates underwent an increase (+7% and +49%). For the sea turtle species CAT (Caretta caretta)and LOL (Lepidochelys olivacea), the nominal catch rates using alternate hooks and baits tested were generally found to increase (+2%, +557%) and (+203%, –66%), respectively. Standardized log normal CPUEs showed that “zone” was the most important significant factor explaining the variability in the CPUE of all the species. “Hook type” was only significant in the billfish group, while “bait type” proved to be significant for the shortfinmako, several other fish and the sea turtleC. caretta. The interaction between bait and other factors were also significant for some species. The mean standardized CPUE data also suggest that the use of alternative hooks could cause variations in the CPUE of swordfish (+14% and – 11%) depending on the type of bait combined. The circle hook would lead to losses for this species (– 11% and –1%) depending on the type of bait combined. A comparison of the standardized CPUEs would suggest that changing the hook and maintaining the same type of bait could result in an increase in the level of sea turtles by-catch that become hookedin external or internal locations. The use of squid as bait instead of mackerel would cause a considerable increase in the number of some species of sea turtles being hooked either externally or internally, regardless of the type of hook used. No seabird interaction occurred during the whole ... Report South Atlantic Ocean Digital.CSIC (Spanish National Research Council) |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
topic |
Pesquerías Centro Oceanográfico de A Coruña Longline CPUE hook bait swordfish sea turtles sea birds |
spellingShingle |
Pesquerías Centro Oceanográfico de A Coruña Longline CPUE hook bait swordfish sea turtles sea birds Mejuto-García, Jaime García-Cortés, Blanca Ramos-Cartelle, Ana Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean |
topic_facet |
Pesquerías Centro Oceanográfico de A Coruña Longline CPUE hook bait swordfish sea turtles sea birds |
description |
Three types of hooks and baits were tested on two swordfish longliners over a period of 480 days at sea in five zones of the North and South Atlantic Ocean. Nominal CPUE data would suggest that the overall catch rates in weight of the fish species in general were reduced with the alternate hooks and baits tested. Overall rates (+7% and –8%) and (+3% and –11%) were found for the swordfish and blue shark, respectively in relation to the hook and bait combination of reference. The shortfin mako exhibited substantial decreases (–9% and –61%). For the billfish group, however, the all rates underwent an increase (+7% and +49%). For the sea turtle species CAT (Caretta caretta)and LOL (Lepidochelys olivacea), the nominal catch rates using alternate hooks and baits tested were generally found to increase (+2%, +557%) and (+203%, –66%), respectively. Standardized log normal CPUEs showed that “zone” was the most important significant factor explaining the variability in the CPUE of all the species. “Hook type” was only significant in the billfish group, while “bait type” proved to be significant for the shortfinmako, several other fish and the sea turtleC. caretta. The interaction between bait and other factors were also significant for some species. The mean standardized CPUE data also suggest that the use of alternative hooks could cause variations in the CPUE of swordfish (+14% and – 11%) depending on the type of bait combined. The circle hook would lead to losses for this species (– 11% and –1%) depending on the type of bait combined. A comparison of the standardized CPUEs would suggest that changing the hook and maintaining the same type of bait could result in an increase in the level of sea turtles by-catch that become hookedin external or internal locations. The use of squid as bait instead of mackerel would cause a considerable increase in the number of some species of sea turtles being hooked either externally or internally, regardless of the type of hook used. No seabird interaction occurred during the whole ... |
format |
Report |
author |
Mejuto-García, Jaime García-Cortés, Blanca Ramos-Cartelle, Ana |
author_facet |
Mejuto-García, Jaime García-Cortés, Blanca Ramos-Cartelle, Ana |
author_sort |
Mejuto-García, Jaime |
title |
Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean |
title_short |
Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean |
title_full |
Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean |
title_fullStr |
Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean |
title_full_unstemmed |
Trials using different hook and bait types in the configuration of the surface longline gear used by the Spanish swordfish (Xiphias gladius) fishery in the Atlantic Ocean |
title_sort |
trials using different hook and bait types in the configuration of the surface longline gear used by the spanish swordfish (xiphias gladius) fishery in the atlantic ocean |
publishDate |
2008 |
url |
http://hdl.handle.net/10508/3457 http://hdl.handle.net/10261/322233 |
op_coverage |
Madrid (España) |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_relation |
Centro Oceanográfico de A Coruña VoR Grupo de especies de ICCAT. (23/09/2007 - 25/09/2007. Madrid, España). 2008. Col. Vol. Sci. Pap. ICCAT, 60(6) http://hdl.handle.net/10508/3457 http://hdl.handle.net/10261/322233 488 |
op_rights |
open |
_version_ |
1790608071905509376 |