Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark
During the fishing process, fish react to a trawl with a series of behaviours that often are species and size specific. Thus, a thorough understanding of fish behaviour in relation to fishing gear and a scientific understanding of the ability of different gear designs to utilize or stimulate various...
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ftdtupubl:oai:pure.atira.dk:publications/c8e48687-5035-4361-a7bc-cb79f062dbae 2024-04-28T08:19:36+00:00 Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark Krag, Ludvig Ahm Herrmann, Bent Karlsen, Junita Diana 2014 application/pdf https://orbit.dtu.dk/en/publications/c8e48687-5035-4361-a7bc-cb79f062dbae https://doi.org/10.1371/journal.pone.0088819 https://backend.orbit.dtu.dk/ws/files/90189058/krag.pdf eng eng https://orbit.dtu.dk/en/publications/c8e48687-5035-4361-a7bc-cb79f062dbae info:eu-repo/semantics/openAccess Krag , L A , Herrmann , B & Karlsen , J D 2014 , ' Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark ' , PLOS ONE , vol. 9 , no. 2 , e88819 . https://doi.org/10.1371/journal.pone.0088819 article 2014 ftdtupubl https://doi.org/10.1371/journal.pone.0088819 2024-04-03T15:11:51Z During the fishing process, fish react to a trawl with a series of behaviours that often are species and size specific. Thus, a thorough understanding of fish behaviour in relation to fishing gear and a scientific understanding of the ability of different gear designs to utilize or stimulate various behavioural patterns during the catching process are essential for developing more efficient, selective, and environmentally friendly trawls. Although many behavioural studies using optical and acoustic observation systems have been conducted, harsh observation conditions on the fishing grounds often hamper the ability to directly observe fish behaviour in relation to fishing gear. As an alternative to optical and acoustic methods, we developed and applied a new mathematical model to catch data to extract detailed and quantitative information about species- and size-dependent escape behaviour in towed fishing gear such as trawls. We used catch comparison data collected with a twin trawl setup; the only difference between the two trawls was that a 12 m long upper section was replaced with 800 mm diamond meshes in one of them. We investigated the length-based escape behaviour of cod (Gadus morhua), haddock Melanogrammus aeglefinus), saithe (Pollachius virens), witch flounder (Glyptocephalus cynoglossus), and lemon sole (Microstomus kitt) and quantified the extent to which behavioural responses set limits for the large mesh panel’s selective efficiency. Around 85% of saithe, 80% of haddock, 44% of witch flounder, 55% of lemon sole, and 55% of cod (below 68 cm) contacted the large mesh panel and escaped. We also demonstrated the need to account for potential selectivity in the trawl body, as it can bias the assessment of length-based escape behaviour. Our indirect assessment of fish behaviour was in agreement with the direct observations made for the same species in a similar section of the trawl body reported in the literature Article in Journal/Newspaper Gadus morhua Technical University of Denmark: DTU Orbit PLoS ONE 9 2 e88819 |
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Open Polar |
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Technical University of Denmark: DTU Orbit |
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ftdtupubl |
language |
English |
description |
During the fishing process, fish react to a trawl with a series of behaviours that often are species and size specific. Thus, a thorough understanding of fish behaviour in relation to fishing gear and a scientific understanding of the ability of different gear designs to utilize or stimulate various behavioural patterns during the catching process are essential for developing more efficient, selective, and environmentally friendly trawls. Although many behavioural studies using optical and acoustic observation systems have been conducted, harsh observation conditions on the fishing grounds often hamper the ability to directly observe fish behaviour in relation to fishing gear. As an alternative to optical and acoustic methods, we developed and applied a new mathematical model to catch data to extract detailed and quantitative information about species- and size-dependent escape behaviour in towed fishing gear such as trawls. We used catch comparison data collected with a twin trawl setup; the only difference between the two trawls was that a 12 m long upper section was replaced with 800 mm diamond meshes in one of them. We investigated the length-based escape behaviour of cod (Gadus morhua), haddock Melanogrammus aeglefinus), saithe (Pollachius virens), witch flounder (Glyptocephalus cynoglossus), and lemon sole (Microstomus kitt) and quantified the extent to which behavioural responses set limits for the large mesh panel’s selective efficiency. Around 85% of saithe, 80% of haddock, 44% of witch flounder, 55% of lemon sole, and 55% of cod (below 68 cm) contacted the large mesh panel and escaped. We also demonstrated the need to account for potential selectivity in the trawl body, as it can bias the assessment of length-based escape behaviour. Our indirect assessment of fish behaviour was in agreement with the direct observations made for the same species in a similar section of the trawl body reported in the literature |
format |
Article in Journal/Newspaper |
author |
Krag, Ludvig Ahm Herrmann, Bent Karlsen, Junita Diana |
spellingShingle |
Krag, Ludvig Ahm Herrmann, Bent Karlsen, Junita Diana Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark |
author_facet |
Krag, Ludvig Ahm Herrmann, Bent Karlsen, Junita Diana |
author_sort |
Krag, Ludvig Ahm |
title |
Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark |
title_short |
Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark |
title_full |
Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark |
title_fullStr |
Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark |
title_full_unstemmed |
Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark |
title_sort |
inferring fish escape behaviour in trawls based on catch comparison data: model development and evaluation based on data from skagerrak, denmark |
publishDate |
2014 |
url |
https://orbit.dtu.dk/en/publications/c8e48687-5035-4361-a7bc-cb79f062dbae https://doi.org/10.1371/journal.pone.0088819 https://backend.orbit.dtu.dk/ws/files/90189058/krag.pdf |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Krag , L A , Herrmann , B & Karlsen , J D 2014 , ' Inferring fish escape behaviour in trawls based on catch comparison data: Model development and evaluation based on data from Skagerrak, Denmark ' , PLOS ONE , vol. 9 , no. 2 , e88819 . https://doi.org/10.1371/journal.pone.0088819 |
op_relation |
https://orbit.dtu.dk/en/publications/c8e48687-5035-4361-a7bc-cb79f062dbae |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1371/journal.pone.0088819 |
container_title |
PLoS ONE |
container_volume |
9 |
container_issue |
2 |
container_start_page |
e88819 |
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1797583013010210816 |