Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil
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Redalyc · Ciencias Marinas
The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were ana...
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| Format: | Artículo científico |
| Language: | en |
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Universidad Autónoma de Baja California
2012
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| _version_ | 1878325299946455040 |
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| author | M. Freitas Nery |
| author_facet | M. Freitas Nery |
| collection | Ciencias Marinas |
| container_title | Ciencias Marinas |
| contents | Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil M. Freitas Nery S. Marino Simão Ciencias de la Tierra photo capture recapture Sepetiba Bay identification The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique. 2012 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48024401005 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.3 Vol.38 |
| ctrlnum | oai:cienciasmarinas.com.mx:article/2012 10.7773/cm.v38i3.2012 |
| description | The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique.
El objetivo de ese estudio fue estimar la abundancia de Sotalia guianensis en la bahía de Sepetiba, sureste de Brasil, con base en la identificación fotográfica de los animales. Se obtuvieron estimaciones del tamaño poblacional mediante modelos de captura-recaptura para una población cerrada. Los datos de foto-identificación fueron analizados usando una aproximación de ajuste de modelos en los programas CAPTURE y MARK, y los estimadores Schnabel y Schumacher-Eschmeyer también fueron usados para calcular la abundancia de los distintos individuos. Estas estimaciones fueron corregidas para incluir individuos no marcados usando datos de la proporción de los individuos identificables en esa población. Durante las salidas de campo entre abril de 2006 y abril de 2007, se tomaron 9990 fotografías de los delfines y de éstas, 2567 fueron de calidad suficiente para los análisis. En total, 382 delfines fueron identificados y catalogados a partir de sus marcas distintivas en la aleta dorsal y entre estos, 153 delfines fueron fotografiados en más de una ocasión. Las estimaciones de abundancia resultantes, escaladas para tener en cuenta la proporción (0.47) de delfines no marcados en la población, mostraron una sobreposición entre los estimadores, de 1004 a 1099 individuos. Esta es la mayor abundancia estimada para una población de S. guianensis registrada hasta la fecha usando la técnica de captura-recaptura. |
| format | Artículo científico |
| id | redalyc_48024401005 |
| institution | Redalyc Ciencias Marinas |
| language | en |
| publishDate | 2012 |
| publisher | Universidad Autónoma de Baja California |
| spelling | Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil Estimación de abundancia por captura-recaptura de los delfines Guiana en el sureste de Brasil Freitas-Nery, M Marino-Simão, S The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique. El objetivo de ese estudio fue estimar la abundancia de Sotalia guianensis en la bahía de Sepetiba, sureste de Brasil, con base en la identificación fotográfica de los animales. Se obtuvieron estimaciones del tamaño poblacional mediante modelos de captura-recaptura para una población cerrada. Los datos de foto-identificación fueron analizados usando una aproximación de ajuste de modelos en los programas CAPTURE y MARK, y los estimadores Schnabel y Schumacher-Eschmeyer también fueron usados para calcular la abundancia de los distintos individuos. Estas estimaciones fueron corregidas para incluir individuos no marcados usando datos de la proporción de los individuos identificables en esa población. Durante las salidas de campo entre abril de 2006 y abril de 2007, se tomaron 9990 fotografías de los delfines y de éstas, 2567 fueron de calidad suficiente para los análisis. En total, 382 delfines fueron identificados y catalogados a partir de sus marcas distintivas en la aleta dorsal y entre estos, 153 delfines fueron fotografiados en más de una ocasión. Las estimaciones de abundancia resultantes, escaladas para tener en cuenta la proporción (0.47) de delfines no marcados en la población, mostraron una sobreposición entre los estimadores, de 1004 a 1099 individuos. Esta es la mayor abundancia estimada para una población de S. guianensis registrada hasta la fecha usando la técnica de captura-recaptura. Universidad Autónoma de Baja California, Instituto de Investigaciones Oceanológicas 2012-05-14 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article Artículo Arbitrado application/pdf https://cienciasmarinas.com.mx/index.php/cmarinas/article/view/2012 10.7773/cm.v38i3.2012 Ciencias Marinas; Vol. 38 No. 3 (2012); 529-541 Ciencias Marinas; Vol. 38 Núm. 3 (2012); 529-541 2395-9053 0185-3880 eng https://cienciasmarinas.com.mx/index.php/cmarinas/article/view/2012/1407 ['Redalyc'] redalyc_48024401005 Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil ['Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil', 'M. Freitas Nery', 'Ciencias de la Tierra', 'photo', 'capture', 'recapture', 'Sepetiba Bay', 'identification', 'Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil M. Freitas Nery S. Marino Simão Ciencias de la Tierra photo capture recapture Sepetiba Bay identification The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique. 2012 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48024401005 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.3 Vol.38'] ['M. Freitas Nery'] ['M. Freitas Nery'] ['Artículo científico'] ['2012'] ['Universidad Autónoma de Baja California'] ['en'] ['Ciencias de la Tierra', 'photo', 'capture', 'recapture', 'Sepetiba Bay', 'identification'] ['https://www.redalyc.org/articulo.oa?id=48024401005'] ['Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil M. Freitas Nery S. Marino Simão Ciencias de la Tierra photo capture recapture Sepetiba Bay identification The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique. 2012 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48024401005 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.3 Vol.38'] |
| spellingShingle | Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil M. Freitas Nery Ciencias de la Tierra photo capture recapture Sepetiba Bay identification Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil M. Freitas Nery S. Marino Simão Ciencias de la Tierra photo capture recapture Sepetiba Bay identification The objective of this study was to estimate the abundance of Sotalia guianensis in Sepetiba Bay, southeastern Brazil, based on photographic identification of animals. Estimates of population size were obtained using capture-recapture models for a closed population. Photo-identification data were analyzed using a model-fitting approach in the computer programs CAPTURE and MARK, and the Schnabel and Schumacher-Eschmeyer estimators were used to calculate the abundance of individuals with natural marks. These estimates were corrected to include unmarked individuals using data of the proportion of identifiable individuals in this population. During the surveys conducted between April 2006 and April 2007, a total of 9990 photographs of dolphins were taken and, of these, 2567 images were of sufficient quality for analysis; 382 dolphins were identified and catalogued from distinctive nicks and notches on their dorsal fins and, among them, 153 dolphins were photographed on more than one occasion. The resulting abundance estimates, corrected to account for the proportion (0.47) of unmarked dolphins in the population, showed an overlap among estimators ranging from 1004 to 1099 individuals. This is the largest estimated abundance for a population of S. guianensis reported to date using the capture-recapture technique. 2012 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48024401005 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.3 Vol.38 |
| title | Capture-recapture abundance estimate of Guiana dolphins in southeastern Brazil |
| title_alt | Estimación de abundancia por captura-recaptura de los delfines Guiana en el sureste de Brasil |
| topic | Ciencias de la Tierra photo capture recapture Sepetiba Bay identification |
| url | https://www.redalyc.org/articulo.oa?id=48024401005 https://cienciasmarinas.com.mx/index.php/cmarinas/article/view/2012 |