Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region.
Pelagic sharks are an important bycatch in pelagic fisheries, especially for drifting longlines targeting swordfish. In the Cabo Verde Archipelago (tropical NE Atlantic), pelagic shark catches can reach a significant proportion of the total catches. Due to the increased concern on the status of pela...
Published in: | Ecological Indicators |
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Main Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier BV
2020
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Online Access: | http://hdl.handle.net/10508/14674 https://sapientia.ualg.pt/bitstream/10400.1/14880/1/Coelho_2020_Sharks_Indicators_CV_POST-PRINT.pdf https://doi.org/10.1016/j.ecolind.2019.105942 |
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ftieo:oai:repositorio.ieo.es:10508/14674 2023-06-11T04:15:18+02:00 Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. Coelho, R. (Rui) Macías-López, A.D. (Ángel David) Ortiz-de-Urbina-Gutiérrez, J.M. (José María) Martins, A. Monteiro, C. (Carlos) Lino, P. (Pedro) Rosa, D. Santos, C.C. Bach, P. (Pascal) Murua, H. (Hilario) Abaunza, P. (Pablo) Santos Santos, M.N. (Miguel Neves) 2020 http://hdl.handle.net/10508/14674 https://sapientia.ualg.pt/bitstream/10400.1/14880/1/Coelho_2020_Sharks_Indicators_CV_POST-PRINT.pdf https://doi.org/10.1016/j.ecolind.2019.105942 eng eng Elsevier BV Centro Oceanográfico de Santander 1470-160X https://sapientia.ualg.pt/bitstream/10400.1/14880/1/Coelho_2020_Sharks_Indicators_CV_POST-PRINT.pdf http://hdl.handle.net/10508/14674 doi:10.1016/j.ecolind.2019.105942 open access Indices of abundance Longline fisheries Pelagic sharks Population trends Satellite tagging Spatial models research article 2020 ftieo https://doi.org/10.1016/j.ecolind.2019.105942 2023-05-02T23:49:27Z Pelagic sharks are an important bycatch in pelagic fisheries, especially for drifting longlines targeting swordfish. In the Cabo Verde Archipelago (tropical NE Atlantic), pelagic shark catches can reach a significant proportion of the total catches. Due to the increased concern on the status of pelagic shark species, this study was developed to enhance the current knowledge of those sharks in the Cabo Verde region in comparison to the adjacent areas, especially associated with European Union (EU) pelagic longline fishing activity. Stock status indicators for the two main species, blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus), were developed, based on fisheries data from logbooks and onboard scientific observers, including analysis of size frequency distributions and standardized catch-per-unit-of-effort (CPUE) indexes over time. The standardized CPUEs have been stable or increasing for both species in the past 10 years, indicating no signs of local depletion. In terms of sizes, the blue shark catch is composed mainly of adults, which can be a sign of a stable population. On the contrary, the catch of shortfin mako is composed mainly of juveniles, which in conjunction of a decrease of mean size might be a cause of concern, highlighting possible overfishing on the species in the region. Thirty satellite tags, 25 archival miniPATs and 5 SPOT GPS, were deployed in the Cabo Verde Exclusive Economic Zone (EEZ), showing that those species are highly mobile. The biomass and size distributions were modeled with spatial and seasonal models (GAMs) identifying locations where juveniles are predominantly concentrated and that should be prioritized for conservation. This work presents new information on the status of pelagic sharks in the Cabo Verde region in the context of those highly migratory species, and can now be used to promote more sustainable fisheries in the region. Article in Journal/Newspaper Northeast Atlantic Instituto Español de Oceanografía: e-IEO Ecological Indicators 110 105942 |
institution |
Open Polar |
collection |
Instituto Español de Oceanografía: e-IEO |
op_collection_id |
ftieo |
language |
English |
topic |
Indices of abundance Longline fisheries Pelagic sharks Population trends Satellite tagging Spatial models |
spellingShingle |
Indices of abundance Longline fisheries Pelagic sharks Population trends Satellite tagging Spatial models Coelho, R. (Rui) Macías-López, A.D. (Ángel David) Ortiz-de-Urbina-Gutiérrez, J.M. (José María) Martins, A. Monteiro, C. (Carlos) Lino, P. (Pedro) Rosa, D. Santos, C.C. Bach, P. (Pascal) Murua, H. (Hilario) Abaunza, P. (Pablo) Santos Santos, M.N. (Miguel Neves) Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. |
topic_facet |
Indices of abundance Longline fisheries Pelagic sharks Population trends Satellite tagging Spatial models |
description |
Pelagic sharks are an important bycatch in pelagic fisheries, especially for drifting longlines targeting swordfish. In the Cabo Verde Archipelago (tropical NE Atlantic), pelagic shark catches can reach a significant proportion of the total catches. Due to the increased concern on the status of pelagic shark species, this study was developed to enhance the current knowledge of those sharks in the Cabo Verde region in comparison to the adjacent areas, especially associated with European Union (EU) pelagic longline fishing activity. Stock status indicators for the two main species, blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus), were developed, based on fisheries data from logbooks and onboard scientific observers, including analysis of size frequency distributions and standardized catch-per-unit-of-effort (CPUE) indexes over time. The standardized CPUEs have been stable or increasing for both species in the past 10 years, indicating no signs of local depletion. In terms of sizes, the blue shark catch is composed mainly of adults, which can be a sign of a stable population. On the contrary, the catch of shortfin mako is composed mainly of juveniles, which in conjunction of a decrease of mean size might be a cause of concern, highlighting possible overfishing on the species in the region. Thirty satellite tags, 25 archival miniPATs and 5 SPOT GPS, were deployed in the Cabo Verde Exclusive Economic Zone (EEZ), showing that those species are highly mobile. The biomass and size distributions were modeled with spatial and seasonal models (GAMs) identifying locations where juveniles are predominantly concentrated and that should be prioritized for conservation. This work presents new information on the status of pelagic sharks in the Cabo Verde region in the context of those highly migratory species, and can now be used to promote more sustainable fisheries in the region. |
format |
Article in Journal/Newspaper |
author |
Coelho, R. (Rui) Macías-López, A.D. (Ángel David) Ortiz-de-Urbina-Gutiérrez, J.M. (José María) Martins, A. Monteiro, C. (Carlos) Lino, P. (Pedro) Rosa, D. Santos, C.C. Bach, P. (Pascal) Murua, H. (Hilario) Abaunza, P. (Pablo) Santos Santos, M.N. (Miguel Neves) |
author_facet |
Coelho, R. (Rui) Macías-López, A.D. (Ángel David) Ortiz-de-Urbina-Gutiérrez, J.M. (José María) Martins, A. Monteiro, C. (Carlos) Lino, P. (Pedro) Rosa, D. Santos, C.C. Bach, P. (Pascal) Murua, H. (Hilario) Abaunza, P. (Pablo) Santos Santos, M.N. (Miguel Neves) |
author_sort |
Coelho, R. (Rui) |
title |
Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. |
title_short |
Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. |
title_full |
Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. |
title_fullStr |
Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. |
title_full_unstemmed |
Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region. |
title_sort |
local indicators for global species: pelagic sharks in the tropical northeast atlantic, cabo verde islands region. |
publisher |
Elsevier BV |
publishDate |
2020 |
url |
http://hdl.handle.net/10508/14674 https://sapientia.ualg.pt/bitstream/10400.1/14880/1/Coelho_2020_Sharks_Indicators_CV_POST-PRINT.pdf https://doi.org/10.1016/j.ecolind.2019.105942 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
1470-160X https://sapientia.ualg.pt/bitstream/10400.1/14880/1/Coelho_2020_Sharks_Indicators_CV_POST-PRINT.pdf http://hdl.handle.net/10508/14674 doi:10.1016/j.ecolind.2019.105942 |
op_rights |
open access |
op_doi |
https://doi.org/10.1016/j.ecolind.2019.105942 |
container_title |
Ecological Indicators |
container_volume |
110 |
container_start_page |
105942 |
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1768371991479320576 |