http://hdl.handle.net/1834/1366 Thu, 23 May 2013 00:55:39 GMT 2013-05-23T00:55:39Z http://hdl.handle.net/1834/2068 Title: Modelo de optimización para el cálculo de la cuota de captura de langostino amarillo Authors: Albornoz, V.; Canales, C.; Fazzi, R. Abstract: This paper presents a nonlinear optimization model that use to establish an annual quota for the total allowable catch for managing the yellow squat lobster fishery. The proposed bioeconomic model maximizes the economic profits of the activity involved and, simultaneously, takes into account the long-term conservation of the resource by restricting catches and thereby assuring adequate biomass level in the future. The dynamic behavior of the population is incorporated through a single-specie logistic growth model. Parameters (e.g., growth rate, maximun population and ish eort) were estimated based on a sampling technique using historical biomass reports and fishing yields. The results obtained with this methodology are shown, as is their application in managing this particular fishery in the north of Chile. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/1834/2068 2006-01-01T00:00:00Z http://hdl.handle.net/1834/2069 Title: Estado de explotación del recurso besugo (Epigonus crassicaudus) en Chile Authors: Wiff, R.; Quiroz, J.C.; Tascheri, R. Abstract: The exploitation status of cardinalfish (Epigonus crassicaudus) yielded in Chile between 33° to 41°S was analyzed. An indirect assessment was performed between 1997 and 2003 through size-structured model with a transition matrix defining the changes among sizes. The model was calibrated using size structures, official landings, catch-per-unit of effort (CPUE) taken from commercial fishing logbooks and standardized by generalized linear models (GLM). After 7 years of an intense fishery activity, we concluded that the cardinalfish resource in Chile is on the recruitment overfishing limit. On 2003, the spawning biomass with respect to the virginal spawning biomass is close to 40%. The biological references points (BRP) based on spawning per recruit biomass (SPR) support this assesment because the fishing mortality level on 2003 (Fact) was very close to fishing mortality level of 40% of SRP at virginal value (F40%). Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/1834/2069 2005-01-01T00:00:00Z http://hdl.handle.net/1834/2070 Title: Factores que afectan las tasas de captura de langostino amarillo (Cervimunida johni) en la zona norte de Chile Authors: Wiff, R.; Quiroz, J.C.; Montenegro, C. Abstract: An analysis was made of the factors affecting the catch rates of the yellow squat lobster (Cervimunida johni) in Chile’s northern region (26°03’-32°10’S) by reviewing commercial fishing logbooks from 1993 to 2003. Factors evaluated included years, months, depth stratum, fishing areas and fleet characteristics as linear predictors in a generalized linear model (GLM) in order to explain variability in the catch rate. In contrast with other fisheries, with this resource the technical characteristics of the fleet and its’ specialization poorly explain variations in catch rate; temporal factors and their interaction were, however, highly significant. The results of this study, together with the life history of the resource, allow the supposition that standardized catch rates are appropriate as an index of relative abundance in this fishery. Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/1834/2070 2005-01-01T00:00:00Z