Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.

We measured discards survival probabilities of thornback (Raja clavata) and spotted skate (Raja montagui) in tickler chain beam trawling (5 trips, n = 183 for thornback skate, n = 137 for spotted skate), pulse beam trawling (9 trips, n = 94 for thornback skate) and flyshoot fishieres (4 trips, n = 1...

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Main Authors: Edward Schram, Lennert van de Pol, Katinka Bleeker, Pieke Molenaar, Allard van Mens, Jan Jaap Poos, Karolina Molla Gazi, Suzanne Cornelisse, Pim van Dalen, Wouter Suykerbuyk, Jurgen Batsleer
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2024-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0314032
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author Edward Schram
Lennert van de Pol
Katinka Bleeker
Pieke Molenaar
Allard van Mens
Jan Jaap Poos
Karolina Molla Gazi
Suzanne Cornelisse
Pim van Dalen
Wouter Suykerbuyk
Jurgen Batsleer
author_facet Edward Schram
Lennert van de Pol
Katinka Bleeker
Pieke Molenaar
Allard van Mens
Jan Jaap Poos
Karolina Molla Gazi
Suzanne Cornelisse
Pim van Dalen
Wouter Suykerbuyk
Jurgen Batsleer
author_sort Edward Schram
collection DOAJ
description We measured discards survival probabilities of thornback (Raja clavata) and spotted skate (Raja montagui) in tickler chain beam trawling (5 trips, n = 183 for thornback skate, n = 137 for spotted skate), pulse beam trawling (9 trips, n = 94 for thornback skate) and flyshoot fishieres (4 trips, n = 137 for thornback skate, n = 24 for spotted skate). Survival probabilities were measured by captive observation for 15 to 25 days post catch. All fishery operations were conducted in the southern North Sea (ICES division 27.4.c) and in the Eastern English Channel (ICES division 27.7.d) according to the regular commercial practices of the fishing vessels. Trips were spread out over the seasons to account for the effect of variable environmental and fishing conditions on discards survival. Operational and environmental conditions during sea trips were recorded. For beam trawling survival probabilities (95% CI) were 50% (43-57) for thornback and 44% (37-54) for spotted skate. For pulse trawling, survival probability of thornback skate was 54% (40-65). For flyshooting survival probabilities were higher: 80% (73-87) for thornback and 75% (60-94) for spotted skate. Survival probabilities were significantly affected by gear, catch processing time, water temperature, wave height and the interaction between water temperature and wave height. We found no evidence for effects of species and length on survival probability. Vitality class provides a useful qualitative prediction of survival probability within gear. These findings are relevant for the fisheries management of skates stocks in the North Sea and English Channel.
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institution Kabale University
issn 1932-6203
language English
publishDate 2024-01-01
publisher Public Library of Science (PLoS)
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series PLoS ONE
spelling doaj-art-483599ff15a4436eb8289a0c713deaf32025-01-08T05:32:50ZengPublic Library of Science (PLoS)PLoS ONE1932-62032024-01-011912e031403210.1371/journal.pone.0314032Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.Edward SchramLennert van de PolKatinka BleekerPieke MolenaarAllard van MensJan Jaap PoosKarolina Molla GaziSuzanne CornelissePim van DalenWouter SuykerbuykJurgen BatsleerWe measured discards survival probabilities of thornback (Raja clavata) and spotted skate (Raja montagui) in tickler chain beam trawling (5 trips, n = 183 for thornback skate, n = 137 for spotted skate), pulse beam trawling (9 trips, n = 94 for thornback skate) and flyshoot fishieres (4 trips, n = 137 for thornback skate, n = 24 for spotted skate). Survival probabilities were measured by captive observation for 15 to 25 days post catch. All fishery operations were conducted in the southern North Sea (ICES division 27.4.c) and in the Eastern English Channel (ICES division 27.7.d) according to the regular commercial practices of the fishing vessels. Trips were spread out over the seasons to account for the effect of variable environmental and fishing conditions on discards survival. Operational and environmental conditions during sea trips were recorded. For beam trawling survival probabilities (95% CI) were 50% (43-57) for thornback and 44% (37-54) for spotted skate. For pulse trawling, survival probability of thornback skate was 54% (40-65). For flyshooting survival probabilities were higher: 80% (73-87) for thornback and 75% (60-94) for spotted skate. Survival probabilities were significantly affected by gear, catch processing time, water temperature, wave height and the interaction between water temperature and wave height. We found no evidence for effects of species and length on survival probability. Vitality class provides a useful qualitative prediction of survival probability within gear. These findings are relevant for the fisheries management of skates stocks in the North Sea and English Channel.https://doi.org/10.1371/journal.pone.0314032
spellingShingle Edward Schram
Lennert van de Pol
Katinka Bleeker
Pieke Molenaar
Allard van Mens
Jan Jaap Poos
Karolina Molla Gazi
Suzanne Cornelisse
Pim van Dalen
Wouter Suykerbuyk
Jurgen Batsleer
Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.
PLoS ONE
title Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.
title_full Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.
title_fullStr Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.
title_full_unstemmed Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.
title_short Survival probabilities of thornback skate (Raja clavata) and spotted skate (Raja montagui) discarded by tickler chain beam trawl, pulse trawl, and flyshoot fisheries.
title_sort survival probabilities of thornback skate raja clavata and spotted skate raja montagui discarded by tickler chain beam trawl pulse trawl and flyshoot fisheries
url https://doi.org/10.1371/journal.pone.0314032
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