Sustentabilidad de la explotacion del gatuzo Mustelus schmitti, en el ecosistema costero bonaerense (34 - 42°S)
The life history of Chondrichthyans results in a low capacity to recover from the fishery human impact, Mustelus schmitti is the most landing shark in Argentina (SW Atlantic)where reductions in the abundance have been detected. The sustainability of M. schmitti to exploitation using a demographic analysis, was examined. The intrinsic rate of population increase (r)and extinction risk under several harvesting strategies were estimated. For this purpose a stage-structured female-only matrix model was applied, considering the mortality and reproductive parameters to each stage. The estimate of length at maturity from the logistic curve was 56.04 cm. The fertility per female ranged between 1 and 15 pups and it was increased with total length. The Mortality estimation, related to various life history parameters, ranging from 0.139 to 0.412. In the scenario without exploitation the intrinsic rate of population growth (r)was 0.175 and the extinction risk was 0.011. The exploitation was sustainable (r 0)when the proportion of extraction was 0.05, 0.1 and 0.15. This conclusion was obtained though the analysis of strategies with different rates of exploitation. Juveniles and small adults are the most influenced stages of the population growth. Exploitation of large adults was the strategy with bigger population growth possibility and smaller extinction risk.
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| Format: | Theses and Dissertations biblioteca |
| Language: | Spanish / Castilian |
| Published: |
2007
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| Subjects: | Stock assessment, Population structure, Exploitation, Natural mortality, Shark fisheries, |
| Online Access: | http://hdl.handle.net/1834/2597 |
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