Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications

Autores
Crespo, Enrique Alberto; Pedraza, Susana Noemi; Grandi, Maria Florencia; Dans, Silvana Laura; Garaffo, Griselda Valeria
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
This is the first study in Argentine waters on the abundance of the threatened Franciscana dolphin, Pontoporia blainvillei. During 2003-2004 we carried out 17 aerial surveys using line transect sampling methodology. We observed 101 Franciscanas in 71 sightings. In northern areas density was estimated at 0.106 individual/km2. Density was lower in southern areas (0.055/km2) and declined with depth beyond 30-m isobaths (0.05/km2). A correction factor for submerged dolphins was applied to density and then extrapolated to the strip between the coastline and the 30-m isobath. Abundance in the northern area was estimated at 8,279 (4,904-13,960) individuals, while in the southern area it was estimated at 5,896 (1,928-17,999) individuals. Considering an annual mortality of about 500-800 individuals, about 3.5%-5.6% of the stock may be removed each year by the fishery and over the 2% recommended by the International Whaling Commission (IWC) and may not be sustainable by the population. Higher densities in coastal areas make Franciscanas more vulnerable to coastal fishing camps, which increased mortality in recent years. A remarkable finding was that while density decreases to the south, values of catch per unit effort (CPUE) increases, indicating different catchability of dolphins between areas. © 2009 by the Society for Marine Mammalogy.
Fil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Fil: Pedraza, Susana Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Fil: Grandi, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Fil: Dans, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Fil: Garaffo, Griselda Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Materia
Abundance Estimations
Aerial Surveys
Conservation
Franciscana (Pontoporia Blainvillei)
Western South Atlantic
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/63164
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/63164
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implicationsCrespo, Enrique AlbertoPedraza, Susana NoemiGrandi, Maria FlorenciaDans, Silvana LauraGaraffo, Griselda ValeriaAbundance EstimationsAerial SurveysConservationFranciscana (Pontoporia Blainvillei)Western South Atlantichttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1This is the first study in Argentine waters on the abundance of the threatened Franciscana dolphin, Pontoporia blainvillei. During 2003-2004 we carried out 17 aerial surveys using line transect sampling methodology. We observed 101 Franciscanas in 71 sightings. In northern areas density was estimated at 0.106 individual/km2. Density was lower in southern areas (0.055/km2) and declined with depth beyond 30-m isobaths (0.05/km2). A correction factor for submerged dolphins was applied to density and then extrapolated to the strip between the coastline and the 30-m isobath. Abundance in the northern area was estimated at 8,279 (4,904-13,960) individuals, while in the southern area it was estimated at 5,896 (1,928-17,999) individuals. Considering an annual mortality of about 500-800 individuals, about 3.5%-5.6% of the stock may be removed each year by the fishery and over the 2% recommended by the International Whaling Commission (IWC) and may not be sustainable by the population. Higher densities in coastal areas make Franciscanas more vulnerable to coastal fishing camps, which increased mortality in recent years. A remarkable finding was that while density decreases to the south, values of catch per unit effort (CPUE) increases, indicating different catchability of dolphins between areas. © 2009 by the Society for Marine Mammalogy.Fil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; ArgentinaFil: Pedraza, Susana Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; ArgentinaFil: Grandi, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Dans, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; ArgentinaFil: Garaffo, Griselda Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; ArgentinaWiley Blackwell Publishing, Inc2010-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/63164Crespo, Enrique Alberto; Pedraza, Susana Noemi; Grandi, Maria Florencia; Dans, Silvana Laura; Garaffo, Griselda Valeria; Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications; Wiley Blackwell Publishing, Inc; Marine Mammal Science; 26; 1; 1-2010; 17-350824-04691748-7692CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1111/j.1748-7692.2009.00313.xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:49:02Zoai:ri.conicet.gov.ar:11336/63164instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:49:02.703CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
title Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
spellingShingle Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
Crespo, Enrique Alberto
Abundance Estimations
Aerial Surveys
Conservation
Franciscana (Pontoporia Blainvillei)
Western South Atlantic
title_short Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
title_full Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
title_fullStr Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
title_full_unstemmed Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
title_sort Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications
dc.creator.none.fl_str_mv Crespo, Enrique Alberto
Pedraza, Susana Noemi
Grandi, Maria Florencia
Dans, Silvana Laura
Garaffo, Griselda Valeria
author Crespo, Enrique Alberto
author_facet Crespo, Enrique Alberto
Pedraza, Susana Noemi
Grandi, Maria Florencia
Dans, Silvana Laura
Garaffo, Griselda Valeria
author_role author
author2 Pedraza, Susana Noemi
Grandi, Maria Florencia
Dans, Silvana Laura
Garaffo, Griselda Valeria
author2_role author
author
author
author
dc.subject.none.fl_str_mv Abundance Estimations
Aerial Surveys
Conservation
Franciscana (Pontoporia Blainvillei)
Western South Atlantic
topic Abundance Estimations
Aerial Surveys
Conservation
Franciscana (Pontoporia Blainvillei)
Western South Atlantic
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv This is the first study in Argentine waters on the abundance of the threatened Franciscana dolphin, Pontoporia blainvillei. During 2003-2004 we carried out 17 aerial surveys using line transect sampling methodology. We observed 101 Franciscanas in 71 sightings. In northern areas density was estimated at 0.106 individual/km2. Density was lower in southern areas (0.055/km2) and declined with depth beyond 30-m isobaths (0.05/km2). A correction factor for submerged dolphins was applied to density and then extrapolated to the strip between the coastline and the 30-m isobath. Abundance in the northern area was estimated at 8,279 (4,904-13,960) individuals, while in the southern area it was estimated at 5,896 (1,928-17,999) individuals. Considering an annual mortality of about 500-800 individuals, about 3.5%-5.6% of the stock may be removed each year by the fishery and over the 2% recommended by the International Whaling Commission (IWC) and may not be sustainable by the population. Higher densities in coastal areas make Franciscanas more vulnerable to coastal fishing camps, which increased mortality in recent years. A remarkable finding was that while density decreases to the south, values of catch per unit effort (CPUE) increases, indicating different catchability of dolphins between areas. © 2009 by the Society for Marine Mammalogy.
Fil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Fil: Pedraza, Susana Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Fil: Grandi, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Fil: Dans, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
Fil: Garaffo, Griselda Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina
description This is the first study in Argentine waters on the abundance of the threatened Franciscana dolphin, Pontoporia blainvillei. During 2003-2004 we carried out 17 aerial surveys using line transect sampling methodology. We observed 101 Franciscanas in 71 sightings. In northern areas density was estimated at 0.106 individual/km2. Density was lower in southern areas (0.055/km2) and declined with depth beyond 30-m isobaths (0.05/km2). A correction factor for submerged dolphins was applied to density and then extrapolated to the strip between the coastline and the 30-m isobath. Abundance in the northern area was estimated at 8,279 (4,904-13,960) individuals, while in the southern area it was estimated at 5,896 (1,928-17,999) individuals. Considering an annual mortality of about 500-800 individuals, about 3.5%-5.6% of the stock may be removed each year by the fishery and over the 2% recommended by the International Whaling Commission (IWC) and may not be sustainable by the population. Higher densities in coastal areas make Franciscanas more vulnerable to coastal fishing camps, which increased mortality in recent years. A remarkable finding was that while density decreases to the south, values of catch per unit effort (CPUE) increases, indicating different catchability of dolphins between areas. © 2009 by the Society for Marine Mammalogy.
publishDate 2010
dc.date.none.fl_str_mv 2010-01
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/63164
Crespo, Enrique Alberto; Pedraza, Susana Noemi; Grandi, Maria Florencia; Dans, Silvana Laura; Garaffo, Griselda Valeria; Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications; Wiley Blackwell Publishing, Inc; Marine Mammal Science; 26; 1; 1-2010; 17-35
0824-0469
1748-7692
CONICET Digital
CONICET
url http://hdl.handle.net/11336/63164
identifier_str_mv Crespo, Enrique Alberto; Pedraza, Susana Noemi; Grandi, Maria Florencia; Dans, Silvana Laura; Garaffo, Griselda Valeria; Abundance and distribution of endangered Franciscana dolphins in Argentine waters and conservation implications; Wiley Blackwell Publishing, Inc; Marine Mammal Science; 26; 1; 1-2010; 17-35
0824-0469
1748-7692
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1748-7692.2009.00313.x
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.070432

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