SUMMARY
Previous attempts to conduct a stock assessment for the blue shark (Prionace glauca) in the North Atlantic have been handicapped by the lack of reliable catch and effort data. The use of tag-recapture data is among ICCAT’s recommendations for future assessment work. This paper proposes a statistical...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1073
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.525.1377 http://www.iccat.int/Documents/CVSP/CV058_2005/no_3/CV058031073.pdf |
| Summary: | Previous attempts to conduct a stock assessment for the blue shark (Prionace glauca) in the North Atlantic have been handicapped by the lack of reliable catch and effort data. The use of tag-recapture data is among ICCAT’s recommendations for future assessment work. This paper proposes a statistical framework for estimating blue shark movement and fishing mortality rates from the tag-recapture data of the National Marine Fisheries Service Cooperative Shark Tagging Program (NMFS-CSTP). The model considers four geographical regions. Blue sharks can stay in the region in which they were tagged and they can move among regions. The parameters of the model are the intra- and inter-region movement probabilities and the catchability coefficients that relate the probabilities of capture and the ICCAT longline fishing effort data. Bayesian estimation methods are used to estimate and quantify the uncertainty associated with the values for these parameters. The dataset of the NMFS-CSTP shows potential for use in a blue shark stock assessment and should be investigated further. Areas of interest for future research are identified. RÉSUMÉ |
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