The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery
Autor(a) principal: | |
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Data de Publicação: | 2022 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.1/19837 |
Resumo: | The common dolphin, Delphinus delphis, is the most abundant cetacean species along the Portuguese mainland coast and are faced with many anthropogenic threats. Over the past decade, intense fishing practices have contributed to a decline in the availability of their main prey, the sardine. Furthermore, the high Purse Seine Fishing (PSF) activity has raised concern over the level of by-catch along the coast. The purpose of the study is to (i) investigate the distribution of the common dolphin along the Portuguese mainland coast, and (ii) to estimate the overlap between the PSF effort and the common dolphin’s distribution. The study uses sighting data from 2005-2020 to identify dolphin hotspot areas. In addition, the study analyses changes in their offshore distribution across different time periods. Finally, the study overlaps Automatic Information System data of the PSF with common dolphin distribution data, in order to identify high by-catch risk areas. The outputs of the study identify major common dolphin hotspots along the central and southern Portuguese mainland coast, which coincide with important fishing ports and geographic features. Furthermore, the common dolphin was found to occur significantly further from the coast during from 2013-2016 (p-value < 0.05), which corresponds with a period of particularly low sardine biomass. Finally, the by-catch risk assessment reported high risk areas off the western Algarve, particularly near important fishing grounds. The study highlights the major common dolphin hotspots and potential conflict areas with the PSF. These results can be used by managers to inform conservation measures and for the sustainable management of PSF fleet along the Portuguese mainland coast. |
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The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fisheryCommon dolphinBy-catch risk assessmentDistribution mapsPurse seine fisherySardineDomínio/Área Científica::Ciências Naturais::Outras Ciências NaturaisThe common dolphin, Delphinus delphis, is the most abundant cetacean species along the Portuguese mainland coast and are faced with many anthropogenic threats. Over the past decade, intense fishing practices have contributed to a decline in the availability of their main prey, the sardine. Furthermore, the high Purse Seine Fishing (PSF) activity has raised concern over the level of by-catch along the coast. The purpose of the study is to (i) investigate the distribution of the common dolphin along the Portuguese mainland coast, and (ii) to estimate the overlap between the PSF effort and the common dolphin’s distribution. The study uses sighting data from 2005-2020 to identify dolphin hotspot areas. In addition, the study analyses changes in their offshore distribution across different time periods. Finally, the study overlaps Automatic Information System data of the PSF with common dolphin distribution data, in order to identify high by-catch risk areas. The outputs of the study identify major common dolphin hotspots along the central and southern Portuguese mainland coast, which coincide with important fishing ports and geographic features. Furthermore, the common dolphin was found to occur significantly further from the coast during from 2013-2016 (p-value < 0.05), which corresponds with a period of particularly low sardine biomass. Finally, the by-catch risk assessment reported high risk areas off the western Algarve, particularly near important fishing grounds. The study highlights the major common dolphin hotspots and potential conflict areas with the PSF. These results can be used by managers to inform conservation measures and for the sustainable management of PSF fleet along the Portuguese mainland coast.Gonçalves, J. M. S.Marçalo, AnaSapientiaBrouder, Sarah2023-07-18T12:32:28Z2022-07-132022-07-13T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10400.1/19837TID:203230078enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-24T10:32:23Zoai:sapientia.ualg.pt:10400.1/19837Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:09:23.473766Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
title |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
spellingShingle |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery Brouder, Sarah Common dolphin By-catch risk assessment Distribution maps Purse seine fishery Sardine Domínio/Área Científica::Ciências Naturais::Outras Ciências Naturais |
title_short |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
title_full |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
title_fullStr |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
title_full_unstemmed |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
title_sort |
The spatial distribution of the common dolphin, Delphinus delphis, along the Portuguese mainland coast and their interaction with the purse seine fishery |
author |
Brouder, Sarah |
author_facet |
Brouder, Sarah |
author_role |
author |
dc.contributor.none.fl_str_mv |
Gonçalves, J. M. S. Marçalo, Ana Sapientia |
dc.contributor.author.fl_str_mv |
Brouder, Sarah |
dc.subject.por.fl_str_mv |
Common dolphin By-catch risk assessment Distribution maps Purse seine fishery Sardine Domínio/Área Científica::Ciências Naturais::Outras Ciências Naturais |
topic |
Common dolphin By-catch risk assessment Distribution maps Purse seine fishery Sardine Domínio/Área Científica::Ciências Naturais::Outras Ciências Naturais |
description |
The common dolphin, Delphinus delphis, is the most abundant cetacean species along the Portuguese mainland coast and are faced with many anthropogenic threats. Over the past decade, intense fishing practices have contributed to a decline in the availability of their main prey, the sardine. Furthermore, the high Purse Seine Fishing (PSF) activity has raised concern over the level of by-catch along the coast. The purpose of the study is to (i) investigate the distribution of the common dolphin along the Portuguese mainland coast, and (ii) to estimate the overlap between the PSF effort and the common dolphin’s distribution. The study uses sighting data from 2005-2020 to identify dolphin hotspot areas. In addition, the study analyses changes in their offshore distribution across different time periods. Finally, the study overlaps Automatic Information System data of the PSF with common dolphin distribution data, in order to identify high by-catch risk areas. The outputs of the study identify major common dolphin hotspots along the central and southern Portuguese mainland coast, which coincide with important fishing ports and geographic features. Furthermore, the common dolphin was found to occur significantly further from the coast during from 2013-2016 (p-value < 0.05), which corresponds with a period of particularly low sardine biomass. Finally, the by-catch risk assessment reported high risk areas off the western Algarve, particularly near important fishing grounds. The study highlights the major common dolphin hotspots and potential conflict areas with the PSF. These results can be used by managers to inform conservation measures and for the sustainable management of PSF fleet along the Portuguese mainland coast. |
publishDate |
2022 |
dc.date.none.fl_str_mv |
2022-07-13 2022-07-13T00:00:00Z 2023-07-18T12:32:28Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.1/19837 TID:203230078 |
url |
http://hdl.handle.net/10400.1/19837 |
identifier_str_mv |
TID:203230078 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799133341452075008 |