Estructura y dinámica poblacional de la corvina rubia (Micropogonias furnieri, Desmarest, 1823) del extremo sur de su distribución (Pcia. Buenos Aires, Argentina).
The whitemouth croacker, Micropogonias furnieri (Desmarest, 1823), is widely distributed in the SW Atlantic. Like other Sciaenidae, it is a coastal species, hence accesible to fishermen, also valuable due to the quality of the product. This Thesis analyzes biological and fisheries aspects of the species between 34° and 42° S. In the study area, a northern (Río de La Plata and Argentine-Uruguayan Common Fishing Zone (ZCPAU) and a southern (El Rincón) zone are established. However, due to the scarce biological information in the latter, results mainly come from the northern area. In order to understand the life strategy of the whitemouth croacker, life history aspects, such as feeding, reproduction, spatial distribution, and size structure were analyzed and population parameters, such as growth and, mortality- were estimated. In a fisheries context, the trends of indicators, i.e. structure and percentage of juveniles in landings, commercial fleet abundance index, trend of total biomass, were studied from fisheries data obtained between 1992 and 2010. M. furnieri is a long-living species (up to 45 years old), with growth parameters coincident with other sciaenids. Growth differences between sexes were found, being females larger than males. K values ranged between 0.15 and 0.26 (mean K = 0.18) and natural mortality ranged between 0.10 and 0.26 for the total number of individuals studied. Considering recent theories about life cycles and strategies, the whitemouth croacker could be placed in an intermediate and periodical strategy. Traditional theories indicate that the species corresponds to a K strategy, susceptible to overfishing with a low recovery rate. However, the species is more resilient to fishing pressure than others due to its adaptation to environmental stress, long spawning period, and wide dietary preferences. At its southernmost limit of distribution in South America, the whitemouth croacker is intensively fished in Argentina and Uruguay, where catches increased during the last years. This increase is related to the high number of vessels in the area which exceeded the recommended biologically acceptable catches. Reduction of mean size, mainly composed by juveniles, was evidenced in the landings as the fleet increased activity in areas of concentration of juveniles. Biological reference coefficients derived from assessment models indicate that the present biomass levels do not reach the optimal values. The state of the art in the study area is understood by authorities and management rules exist; only their compliment and control could permit the sustainability of the resource.
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| Format: | Thesis/Dissertation biblioteca |
| Language: | Spanish / Castilian |
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Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales
2012
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| Subjects: | Sciaenidae, Micropogonias furnieri, Corvina, Dinámica poblacional, Pesquería costera, Crecimiento, Mortalidad natural, Estadísticas de desembarque, Captura/esfuerzo, Efectivos compartidos, ASFA15::P::Population dynamics, ASFA15::C::Coastal fisheries, ASFA15::G::Growth, ASFA15::N::Natural mortality, ASFA15::L::Landing statistics, ASFA15::C::Catch/effort, ASFA15::S::Shared stocks, |
| Online Access: | http://hdl.handle.net/1834/6825 |
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