Indeterminate status of West African populations of inshore common bottlenose dolphins Tursiops truncatus caution against opportunistic live-capture schemes
Van Waerebeek, K.; Bamy, I.L.; Jiddou, A.M.; Sequeira, M.; Diop, M.; Ofori-Danson, P.K.; Tchibozo, S.; Campredon, P. (2008). Indeterminate status of West African populations of inshore common bottlenose dolphins Tursiops truncatus caution against opportunistic live-capture schemes. Fondation Internationale du Banc d'Arguin: [s.l.]. 9 pp.
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| Authors | | Top |
- Van Waerebeek, K., more
- Bamy, I.L.
- Jiddou, A.M.
- Sequeira, M.
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- Diop, M.
- Ofori-Danson, P.K.
- Tchibozo, S.
- Campredon, P.
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| Abstract |
The limited information available on the status of inshore common bottlenose dolphins Tursiops truncatus along the coasts of West Africa is reviewed. Although reported from at least ten countries, it is unclear whether their distribution is continuous. Population structure and genetics have not been studied, however cranial morphology suggests that the West African dolphins differ from North Sea bottlenose dolphins. Mean group sizes are small (3.19 – 12.91 individuals/group) and are smallest in Guinea-Bissau. There are no estimates of abundance but by analogy with a well-studied population in Sarasota, Gulf of Mexico, the Guinea-Bissau population may number only in the hundreds. It is essential that scientific estimates be obtained through dedicated surveys. In some areas of Guinea-Bissau with a high density of fishing activities, bottlenose dolphins are now less frequently encountered than they were in the recent past. Key parameters besides abundance, including population identity, bycatch levels and other anthropogenic threats need to be documented and quantified before any deliberate exploitation is considered. A small-scale, botched live-capture operation in Senegal in 2003, in which all dolphins died, serves as warning against such opportunistic schemes. In management terms, live-capture operations are equivalent to hunting and multi-year, large-scale removals of bottlenose dolphins in Guinea-Bissau would have the potential to effectively extirpate the wild population from its waters. |
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