Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries
Abstract The reliability of estimations of catches of pelagic longline fisheries is especially worrying in the case of non-target species such as the sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri), because they are often recorded aggregated in onboard maps. For this reason,...
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| Format: | Article |
| Language: | English |
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Islamic Azad University
2016-11-01
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| Series: | International Aquatic Research |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1007/s40071-016-0149-7 |
| _version_ | 1818775915908300800 |
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| author | Renata Maria Medeiros-Silva Humber Agrelli Andrade |
| author_facet | Renata Maria Medeiros-Silva Humber Agrelli Andrade |
| author_sort | Renata Maria Medeiros-Silva |
| collection | DOAJ |
| description | Abstract The reliability of estimations of catches of pelagic longline fisheries is especially worrying in the case of non-target species such as the sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri), because they are often recorded aggregated in onboard maps. For this reason, generalized linear models were used to identify a number of important explanatory variables and their effect on sailfish and spearfish proportions. The response variable (number of sailfish in the aggregate capture) is assumed as binomial using the logit link function. The explanatory variables used were foram year, qrt (quarter), fleet, de (distance from equator) and d (distance from areas above sea level). The selected models showed that the equatorial and coastal regions presented higher densities or catchabilities of sailfish when compared to spearfish, as in the case for fleets of China Taipei and the United States. The lowest mean proportion of sailfish [sailfish/(sailfish + spearfish)] of the third quarter were driven mostly by the low estimations calculated for Japan and Brazil. |
| first_indexed | 2024-12-18T11:04:38Z |
| format | Article |
| id | doaj.art-284f95da2bc44983bb5701ec549156dd |
| institution | Directory Open Access Journal |
| issn | 2008-4935 2008-6970 |
| language | English |
| last_indexed | 2024-12-18T11:04:38Z |
| publishDate | 2016-11-01 |
| publisher | Islamic Azad University |
| record_format | Article |
| series | International Aquatic Research |
| spelling | doaj.art-284f95da2bc44983bb5701ec549156dd2022-12-21T21:10:08ZengIslamic Azad UniversityInternational Aquatic Research2008-49352008-69702016-11-018434335210.1007/s40071-016-0149-7Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheriesRenata Maria Medeiros-Silva0Humber Agrelli Andrade1Department of Fisheries and Aquaculture, Federal Rural University of PernambucoDepartment of Fisheries and Aquaculture, Federal Rural University of PernambucoAbstract The reliability of estimations of catches of pelagic longline fisheries is especially worrying in the case of non-target species such as the sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri), because they are often recorded aggregated in onboard maps. For this reason, generalized linear models were used to identify a number of important explanatory variables and their effect on sailfish and spearfish proportions. The response variable (number of sailfish in the aggregate capture) is assumed as binomial using the logit link function. The explanatory variables used were foram year, qrt (quarter), fleet, de (distance from equator) and d (distance from areas above sea level). The selected models showed that the equatorial and coastal regions presented higher densities or catchabilities of sailfish when compared to spearfish, as in the case for fleets of China Taipei and the United States. The lowest mean proportion of sailfish [sailfish/(sailfish + spearfish)] of the third quarter were driven mostly by the low estimations calculated for Japan and Brazil.http://link.springer.com/article/10.1007/s40071-016-0149-7Generalized linear modelsVariablesFisheryBycatch |
| spellingShingle | Renata Maria Medeiros-Silva Humber Agrelli Andrade Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries International Aquatic Research Generalized linear models Variables Fishery Bycatch |
| title | Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries |
| title_full | Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries |
| title_fullStr | Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries |
| title_full_unstemmed | Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries |
| title_short | Proportions of Atlantic sailfish (Istiophorus platypterus) and spearfish (Tetrapturus pfluegeri) caught in tuna longline fisheries |
| title_sort | proportions of atlantic sailfish istiophorus platypterus and spearfish tetrapturus pfluegeri caught in tuna longline fisheries |
| topic | Generalized linear models Variables Fishery Bycatch |
| url | http://link.springer.com/article/10.1007/s40071-016-0149-7 |
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