Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids

Fish behaviour affects the performance of selection devices in fishing gears. Traditionally, fish behaviour in relation to selection devices is assessed by direct observation. However, this approach has limitations, and the observations are not explicitly incorporated in the selectivity models. Furt...

Full description

Saved in:
Bibliographic Details
Main Authors: Nadine Jacques, Bent Herrmann, Jesse Brinkhof, Manu Sistiaga
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2025-05-01
Series:Aquaculture and Fisheries
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2468550X24000273
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849326075408023552
author Nadine Jacques
Bent Herrmann
Jesse Brinkhof
Manu Sistiaga
author_facet Nadine Jacques
Bent Herrmann
Jesse Brinkhof
Manu Sistiaga
author_sort Nadine Jacques
collection DOAJ
description Fish behaviour affects the performance of selection devices in fishing gears. Traditionally, fish behaviour in relation to selection devices is assessed by direct observation. However, this approach has limitations, and the observations are not explicitly incorporated in the selectivity models. Further, underwater observations and quantification of fish behaviour can be challenging. In this study we outline and use an indirect method to explicitly incorporate and quantify fish behaviour in trawl selectivity analysis. We use a set of structural models, which are based on modelling the actual processes believed to determine the size selection of the device, to discern which behaviours are most likely to explain the selectivity process. By bootstrapping we assess how confident we can be in the choice of a specific structural model and on discerning the associated behavioural aspects. We collected size selectivity data in the Barents Sea demersal trawl fishery targeting gadoids, where the use of a sorting grid is compulsory. Using our modelling approach, we obtained deeper understanding of which behavioural processes most likely affect size selectivity in the sorting grids tested. Our approach can be applied to other fishing gears to understand and quantify fish behaviour in relation to size selectivity.
format Article
id doaj-art-c6633e5f0bb74b70b4fef7dafd96e495
institution Kabale University
issn 2468-550X
language English
publishDate 2025-05-01
publisher KeAi Communications Co., Ltd.
record_format Article
series Aquaculture and Fisheries
spelling doaj-art-c6633e5f0bb74b70b4fef7dafd96e4952025-08-20T03:48:14ZengKeAi Communications Co., Ltd.Aquaculture and Fisheries2468-550X2025-05-0110349951310.1016/j.aaf.2024.03.003Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting gridsNadine Jacques0Bent Herrmann1Jesse Brinkhof2Manu Sistiaga3UiT, The Arctic University of Norway, Tromsø, 9010, Norway; Corresponding author.UiT, The Arctic University of Norway, Tromsø, 9010, Norway; Department of Fishing Gear Technology, SINTEF Ocean, Trondheim, 7465, Norway; DTU Aqua, Technical University of Denmark, Hirtshals, 1019850, DenmarkUiT, The Arctic University of Norway, Tromsø, 9010, Norway; Norwegian Institute of Marine Research, Postbox 1870 Nordnes, Bergen, N-5817, NorwayUiT, The Arctic University of Norway, Tromsø, 9010, Norway; Norwegian Institute of Marine Research, Postbox 1870 Nordnes, Bergen, N-5817, NorwayFish behaviour affects the performance of selection devices in fishing gears. Traditionally, fish behaviour in relation to selection devices is assessed by direct observation. However, this approach has limitations, and the observations are not explicitly incorporated in the selectivity models. Further, underwater observations and quantification of fish behaviour can be challenging. In this study we outline and use an indirect method to explicitly incorporate and quantify fish behaviour in trawl selectivity analysis. We use a set of structural models, which are based on modelling the actual processes believed to determine the size selection of the device, to discern which behaviours are most likely to explain the selectivity process. By bootstrapping we assess how confident we can be in the choice of a specific structural model and on discerning the associated behavioural aspects. We collected size selectivity data in the Barents Sea demersal trawl fishery targeting gadoids, where the use of a sorting grid is compulsory. Using our modelling approach, we obtained deeper understanding of which behavioural processes most likely affect size selectivity in the sorting grids tested. Our approach can be applied to other fishing gears to understand and quantify fish behaviour in relation to size selectivity.http://www.sciencedirect.com/science/article/pii/S2468550X24000273Structural modelsSize selectivityFish behaviourBootstrap model selectionBottom trawlSorting grids
spellingShingle Nadine Jacques
Bent Herrmann
Jesse Brinkhof
Manu Sistiaga
Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids
Aquaculture and Fisheries
Structural models
Size selectivity
Fish behaviour
Bootstrap model selection
Bottom trawl
Sorting grids
title Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids
title_full Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids
title_fullStr Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids
title_full_unstemmed Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids
title_short Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids
title_sort understanding size selectivity of trawls using structural models methodology and a case study on fish sorting grids
topic Structural models
Size selectivity
Fish behaviour
Bootstrap model selection
Bottom trawl
Sorting grids
url http://www.sciencedirect.com/science/article/pii/S2468550X24000273
work_keys_str_mv AT nadinejacques understandingsizeselectivityoftrawlsusingstructuralmodelsmethodologyandacasestudyonfishsortinggrids
AT bentherrmann understandingsizeselectivityoftrawlsusingstructuralmodelsmethodologyandacasestudyonfishsortinggrids
AT jessebrinkhof understandingsizeselectivityoftrawlsusingstructuralmodelsmethodologyandacasestudyonfishsortinggrids
AT manusistiaga understandingsizeselectivityoftrawlsusingstructuralmodelsmethodologyandacasestudyonfishsortinggrids