Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids
[EN] The Mediterranean fishery has experienced a decline in catches over the past 20 years due to an excessive increase in effort caused by both increased trawler engine power and rapid technological advances in fishing technology and fish location. This has led to overexploitation, in which immature individuals support an increasing portion of the catches. The present study was undertaken to test a sorting grid and square-mesh-panel as juvenile exclusion systems. Our experience was a pilot study of such a system in the western Mediterranean. The purpose of these exclusion systems was to help juvenile hake escape from the net. The results demonstrate that the use of sorting grids for small fish in trawl gears in the Mediterranean is an efficient and practical means of avoiding the capture and discarding of unwanted individuals, with escape rates of over 50% (ranging between 50 and 90%). The grids were efficient and useful for excluding hake (Merluccius merluccius) on bottoms located at depths between 50 and 300 m, where hake are found all year round. A bar spacing of 20 mm yielded escape rates of L50 at 18.8 cm TL (L25 = 16.8 cm and L75 = 20.9 cm). Panels made of square meshes achieved poorer results than the grids. The grid system was effective for most of the species caught in the study area
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Format: | artículo biblioteca |
Language: | English |
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CSIC - Instituto de Ciencias del Mar (ICM)
2004-09
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Subjects: | Trawling, Sorting grids, Square mesh, Selectivity, Hake, Merluccius merluccius, Mediterranean Sea, Pesca de arrastre, Rejillas, Malla cuadrada, Selectividad, Merluza, Juveniles, Mediterráneo, |
Online Access: | http://hdl.handle.net/10261/5530 |
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dig-icm-es-10261-55302021-12-17T11:40:27Z Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids Preservación de juveniles de merluza (merluccius merluccius, l.) en la pesquería demersal de arrastre del Mediterráneo occidental, mediante el uso de rejillas separadoras Sardà, Francisco Palomera, Isabel Molí Ferrer, Balbina Trawling Sorting grids Square mesh Selectivity Hake Merluccius merluccius Mediterranean Sea Pesca de arrastre Rejillas Malla cuadrada Selectividad Merluza Juveniles Mediterráneo [EN] The Mediterranean fishery has experienced a decline in catches over the past 20 years due to an excessive increase in effort caused by both increased trawler engine power and rapid technological advances in fishing technology and fish location. This has led to overexploitation, in which immature individuals support an increasing portion of the catches. The present study was undertaken to test a sorting grid and square-mesh-panel as juvenile exclusion systems. Our experience was a pilot study of such a system in the western Mediterranean. The purpose of these exclusion systems was to help juvenile hake escape from the net. The results demonstrate that the use of sorting grids for small fish in trawl gears in the Mediterranean is an efficient and practical means of avoiding the capture and discarding of unwanted individuals, with escape rates of over 50% (ranging between 50 and 90%). The grids were efficient and useful for excluding hake (Merluccius merluccius) on bottoms located at depths between 50 and 300 m, where hake are found all year round. A bar spacing of 20 mm yielded escape rates of L50 at 18.8 cm TL (L25 = 16.8 cm and L75 = 20.9 cm). Panels made of square meshes achieved poorer results than the grids. The grid system was effective for most of the species caught in the study area [ES] Durante los últimos 20 años la pesca en el Mediterráneo ha experimentado un descenso de capturas al mismo tiempo que se detecta un excesivo incremento del esfuerzo, tanto en potencia de las embarcaciones como en avances tecnológicos y de detección de peces. Esto lleva a la sobreexplotación de crecimiento en la cual las capturas recaen principalmente sobre los individuos inmaduros. Este estudio pretende probar varias rejillas separadoras y paños de malla cuadrada como sistemas de exclusión de juveniles en artes de arrastre de fondo, lo cual constituye una primera experiencia piloto en el Mediterráneo. El objetivo del uso de las rejillas y mallas cuadradas es permitir el escape de juveniles de merluza en cantidad y en buenas condiciones. Los resultados demuestran que el uso de los sistemas selectivos rígidos constituye una buena solución, efectiva y práctica, para reducir drásticamente los descartes de especies no deseadas. Las tasas de escape calculadas superan el 50% de los ejemplares pequeños (entre el 50 y el 92%). Estos sistemas fueron muy eficientes para la merluza en fondos entre 50 y 300 m donde se distribuye durante la mayor parte del año. El espacio entre barras fue de 20 mm, el cual produjo tallas de L50 de escape de 18.8 cm (L25 = 16.8 cm y L75 = 20.9 cm). La malla cuadrada dió peores rendimientos de escape que las rejillas These experiments were conducted in the framework of the “Graella” project financed by the Ministerio de Ciencia y Tecnología (PETRI (1995-0497-OP) and the Direcció General de Pesca i Afers Marítims of the Generalitat de Catalunya (DGPAM). Peer reviewed 2008-07-02T11:33:58Z 2008-07-02T11:33:58Z 2004-09 artículo http://purl.org/coar/resource_type/c_6501 Scientia Marina 68(3): 435-444 (2004) 0214-8358 http://hdl.handle.net/10261/5530 10.3989/scimar.2004.68n3435 1886-8134 en http://doi.org/10.3989/scimar.2004.68n3435 open 2272333 bytes application/pdf CSIC - Instituto de Ciencias del Mar (ICM) |
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Trawling Sorting grids Square mesh Selectivity Hake Merluccius merluccius Mediterranean Sea Pesca de arrastre Rejillas Malla cuadrada Selectividad Merluza Juveniles Mediterráneo Trawling Sorting grids Square mesh Selectivity Hake Merluccius merluccius Mediterranean Sea Pesca de arrastre Rejillas Malla cuadrada Selectividad Merluza Juveniles Mediterráneo |
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Trawling Sorting grids Square mesh Selectivity Hake Merluccius merluccius Mediterranean Sea Pesca de arrastre Rejillas Malla cuadrada Selectividad Merluza Juveniles Mediterráneo Trawling Sorting grids Square mesh Selectivity Hake Merluccius merluccius Mediterranean Sea Pesca de arrastre Rejillas Malla cuadrada Selectividad Merluza Juveniles Mediterráneo Sardà, Francisco Palomera, Isabel Molí Ferrer, Balbina Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids |
description |
[EN] The Mediterranean fishery has experienced a decline in catches over the past 20 years due to an excessive increase in effort caused by both increased trawler engine power and rapid technological advances in fishing technology and fish location. This has led to overexploitation, in which immature individuals support an increasing portion of the catches. The present study was undertaken to test a sorting grid and square-mesh-panel as juvenile exclusion systems. Our experience was a pilot study of such a system in the western Mediterranean. The purpose of these exclusion systems was to help juvenile hake escape from the net. The results demonstrate that the use of sorting grids for small fish in trawl gears in the Mediterranean is an efficient and practical means of avoiding the capture and discarding of unwanted individuals, with escape rates of over 50% (ranging between 50 and 90%). The grids were efficient and useful for excluding hake (Merluccius merluccius) on bottoms located at depths between 50 and 300 m, where hake are found all year round. A bar spacing of 20 mm yielded escape rates of L50 at 18.8 cm TL (L25 = 16.8 cm and L75 = 20.9 cm). Panels made of square meshes achieved poorer results than the grids. The grid system was effective for most of the species caught in the study area |
format |
artículo |
topic_facet |
Trawling Sorting grids Square mesh Selectivity Hake Merluccius merluccius Mediterranean Sea Pesca de arrastre Rejillas Malla cuadrada Selectividad Merluza Juveniles Mediterráneo |
author |
Sardà, Francisco Palomera, Isabel Molí Ferrer, Balbina |
author_facet |
Sardà, Francisco Palomera, Isabel Molí Ferrer, Balbina |
author_sort |
Sardà, Francisco |
title |
Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids |
title_short |
Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids |
title_full |
Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids |
title_fullStr |
Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids |
title_full_unstemmed |
Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids |
title_sort |
preservation of juvenile hake (merluccius merluccius l) in the western mediterranean demersal trawl fishery by using sorting grids |
publisher |
CSIC - Instituto de Ciencias del Mar (ICM) |
publishDate |
2004-09 |
url |
http://hdl.handle.net/10261/5530 |
work_keys_str_mv |
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