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dc.contributor.authorCilbiz, Mehmet
dc.contributor.authorAydin, Celalettin
dc.contributor.authorHerrmann, Bent
dc.date.accessioned2022-10-05T06:47:52Z
dc.date.available2022-10-05T06:47:52Z
dc.date.issued2022-09-23
dc.description.abstractThe narrow-clawed crayfish (Pontastacus leptodactylus) is one of the most ecologically and economically important freshwater species in Turkey. However, the harvest of this species has declined from 7937 t in 1984 to 696 t in 2019. One of primary reasons for this decrease in stock is the use of fishing gears with poor size selectivity. In this study, new codend designs were investigated to improve the size selectivity of fyke nets for P. leptodactylus. Seven codends of three different designs were tested: (1) a commercially used standard codend with 34 mm mesh size (Com34); (2) sorting grids with 20 (SG20), 25 (SG25) and 30 mm (SG30) bar spacing attached to the last circle of the net; and (3) a stiff rigged net, the last part of the fyke nets (codend) with 34 (SRN34), 42 (SRN42) and 50 mm (SRN50) mesh size. The average length at 50% retention probability (L<sub>50</sub>) and selection range (SR) (L<sub>75</sub>–L<sub>25</sub>) values of Com34 were 9.4 cm and 3.1 cm, respectively. For the SG20, SG25 and SG30 grids, the L<sub>50</sub> values were 11.3 cm, 11.6 cm and 12.0 cm, while the SR values were 1.4 cm, 1.3 cm and 0.6 cm, respectively. For the SRN34, SRN42 and SRN50 codends, the L<sub>50</sub> values were 10.9 cm, 11.6 cm and 11.6 cm, while the SR values were 2.1 cm, 2.1cm and 1.1 cm, respectively. Overall, the commercial codend resulted in lower L<sub>50</sub> values when the minimum conservation reference length of 10 cm was considered. However, all tested new codend designs showed improved selectivity compared with the standard, with optimum results obtained with SG20. SG20 grid decreased discarding by 15.7% compared to the classic commercial fyke net; thus, this is a very important result for the sustainability of natural P. leptodactylus stocks.en_US
dc.identifier.citationCilbiz, Aydin, Herrmann. New codend designs to improve the size selectivity of fyke net for narrow-clawed crayfish (Pontastacus leptodactylus). Aquatic Living Resources. 2022;35:1-13en_US
dc.identifier.cristinIDFRIDAID 2058489
dc.identifier.doi10.1051/alr/2022014
dc.identifier.issn0990-7440
dc.identifier.issn1765-2952
dc.identifier.urihttps://hdl.handle.net/10037/26979
dc.language.isoengen_US
dc.publisherEDP Sciencesen_US
dc.relation.journalAquatic Living Resources
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2022 The Author(s)en_US
dc.rights.urihttps://creativecommons.org/licenses/by/4.0en_US
dc.rightsAttribution 4.0 International (CC BY 4.0)en_US
dc.titleNew codend designs to improve the size selectivity of fyke net for narrow-clawed crayfish (Pontastacus leptodactylus)en_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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Attribution 4.0 International (CC BY 4.0)
Med mindre det står noe annet, er denne innførselens lisens beskrevet som Attribution 4.0 International (CC BY 4.0)