A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline?
Abstract Historically, the Mediterranean Sea supported a rich shark fauna. Presently, however, populations of most shark species have significantly declined, largely due to intense fishing pressure. Interviews with crew members of bottom trawlers, drifting longliners and bottom longliners operating...
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Online Access: | http://dx.doi.org/10.1002/aqc.3651 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aqc.3651 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/aqc.3651 |
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crwiley:10.1002/aqc.3651 2024-06-23T07:52:05+00:00 A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? Nuez, Ignasi Gazo, Manel Cardona, Luis 2021 http://dx.doi.org/10.1002/aqc.3651 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aqc.3651 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/aqc.3651 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Aquatic Conservation: Marine and Freshwater Ecosystems volume 31, issue 9, page 2369-2380 ISSN 1052-7613 1099-0755 journal-article 2021 crwiley https://doi.org/10.1002/aqc.3651 2024-06-13T04:20:10Z Abstract Historically, the Mediterranean Sea supported a rich shark fauna. Presently, however, populations of most shark species have significantly declined, largely due to intense fishing pressure. Interviews with crew members of bottom trawlers, drifting longliners and bottom longliners operating off the Costa Brava (Catalonia, NE Spain) were conducted between October 2016 and July 2017 in order to gather information on the current bycatch rate of several shark species. Interviews covered 41.2% of the fleet and respondents were asked for the bycatch of selected shark species— Alopias vulpinus , Cetorhinus maximus , Galeorhinus galeus , Hexanchus griseus , Isurus oxyrinchus , Mustelus spp., Prionace glauca , and Squalus acanthias —in two distinct time periods. Bottom trawlers captured the highest diversity of species (eight) followed by bottom longliners (seven), and drifting longliners (three). Most respondents (89.7%) declared having captured at least one shark from 2006 to 2016 but only 56.4% declared having captured at least one shark from 2016 to 2017. From 2016 to 2017, the whole fleet captured 89 specimens of H. griseus (95% confidence interval (CI) = 145, 34), 14 of G. galeus (95% CI = 30, 0), 3 of A. vulpinus (95% CI = 8, 0), 3 of I. oxyrinchus (95% CI = 8, 0), 3 of C. maximus (95% CI = 6, 0), and no Mustelus spp. The total bycatch of P. glauca and S. acanthias was uncertain due to extremely loose confidence intervals. A significant decline was perceived by fishermen in the bycatch of C. maximus and S. acanthias , whereas the bycatch of H. griseus was considered to have remained stable. This study suggests a dramatic reduction in the abundance of most of the medium‐sized and large sharks of the Costa Brava and the likely disappearance of Mustelus spp. from the area. Only H. griseus , S. acanthias , and P. glauca are still being bycaught frequently. Article in Journal/Newspaper Cetorhinus maximus Squalus acanthias Wiley Online Library Aquatic Conservation: Marine and Freshwater Ecosystems 31 9 2369 2380 |
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Wiley Online Library |
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English |
description |
Abstract Historically, the Mediterranean Sea supported a rich shark fauna. Presently, however, populations of most shark species have significantly declined, largely due to intense fishing pressure. Interviews with crew members of bottom trawlers, drifting longliners and bottom longliners operating off the Costa Brava (Catalonia, NE Spain) were conducted between October 2016 and July 2017 in order to gather information on the current bycatch rate of several shark species. Interviews covered 41.2% of the fleet and respondents were asked for the bycatch of selected shark species— Alopias vulpinus , Cetorhinus maximus , Galeorhinus galeus , Hexanchus griseus , Isurus oxyrinchus , Mustelus spp., Prionace glauca , and Squalus acanthias —in two distinct time periods. Bottom trawlers captured the highest diversity of species (eight) followed by bottom longliners (seven), and drifting longliners (three). Most respondents (89.7%) declared having captured at least one shark from 2006 to 2016 but only 56.4% declared having captured at least one shark from 2016 to 2017. From 2016 to 2017, the whole fleet captured 89 specimens of H. griseus (95% confidence interval (CI) = 145, 34), 14 of G. galeus (95% CI = 30, 0), 3 of A. vulpinus (95% CI = 8, 0), 3 of I. oxyrinchus (95% CI = 8, 0), 3 of C. maximus (95% CI = 6, 0), and no Mustelus spp. The total bycatch of P. glauca and S. acanthias was uncertain due to extremely loose confidence intervals. A significant decline was perceived by fishermen in the bycatch of C. maximus and S. acanthias , whereas the bycatch of H. griseus was considered to have remained stable. This study suggests a dramatic reduction in the abundance of most of the medium‐sized and large sharks of the Costa Brava and the likely disappearance of Mustelus spp. from the area. Only H. griseus , S. acanthias , and P. glauca are still being bycaught frequently. |
format |
Article in Journal/Newspaper |
author |
Nuez, Ignasi Gazo, Manel Cardona, Luis |
spellingShingle |
Nuez, Ignasi Gazo, Manel Cardona, Luis A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? |
author_facet |
Nuez, Ignasi Gazo, Manel Cardona, Luis |
author_sort |
Nuez, Ignasi |
title |
A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? |
title_short |
A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? |
title_full |
A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? |
title_fullStr |
A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? |
title_full_unstemmed |
A closer look at the bycatch of medium‐sized and large sharks in the northern Catalan coast (north‐western Mediterranean Sea): Evidence of an ongoing decline? |
title_sort |
closer look at the bycatch of medium‐sized and large sharks in the northern catalan coast (north‐western mediterranean sea): evidence of an ongoing decline? |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1002/aqc.3651 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aqc.3651 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/aqc.3651 |
genre |
Cetorhinus maximus Squalus acanthias |
genre_facet |
Cetorhinus maximus Squalus acanthias |
op_source |
Aquatic Conservation: Marine and Freshwater Ecosystems volume 31, issue 9, page 2369-2380 ISSN 1052-7613 1099-0755 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/aqc.3651 |
container_title |
Aquatic Conservation: Marine and Freshwater Ecosystems |
container_volume |
31 |
container_issue |
9 |
container_start_page |
2369 |
op_container_end_page |
2380 |
_version_ |
1802643299054387200 |