The Use Of A Bioeconomical Model In The Fishery Of The Red Sea Urchin, Strongylocentrotus Franciscanus, From The Northwestern Coast Of Baja California, Mexico

La pesqueria del erizo rojo, Strongylocentrotus franciscanus, recurso importante de Baja California, ha dado muestras de sobreexplotacion. Se aplicaron los modelos de rendimiento por recluta y de optimizacion dinamica de Beverton y Holt para encontrar la talla de primera captura que permite optimizar ganancias y tratar de asegurar la permanencia del recurso para futuras generaciones. Los parametros biologicos usados fueron L = 155 mm, K = 0.22 y M = 0.22. El modelo de rendimiento por recluta sugiere que para maximizar los rendimientos es necesario incrementar la talla de primera captura a 105 mm y aplicar mortalidades por pesca cercanas a 0.65. El modelo de optimizacion dinamica indico que la talla de captura optima y la biomasa optima disminuyen con el aumento de la tasa de descuento, lo que se refleja en una disminucion de los rendimientos. Para tasas de descuento menores que 5%, que se recomiendan para esta pesqueria, la talla optima de captura esta comprendida entre los 110 y 116 mm. Ambos modelos sugieren que la talla minima legal establecida por la Secretaria del Medio Ambiente, Recursos Naturales y Pesca (SEMARNAP) de 80 mm para el erizo rojo esta por debajo de la talla que permite optimizar las ganancias. Para lograr mayores capturas a largo plazo y maximizar el beneficio economico, es necesario incrementar la talla de primera captura a 110 mm. Para el caso de la tasa de descuento de 0% se calculo el intervalo de tiempo en el cual la pesca se efectua a una tasa maxima. Los resultados indicaron que la temporada de pesca puede ser reducida de ocho a cuatro meses. The commercial fishery of the red sea urchin, Strongylocentrotus franciscanus, an important resource in Baja California, is showing signs of overexploitation. The yield per recruit and the Beverton and Holt optimization dynamic models were used to find the size at first capture that allows maximum profits and keeps the resource at a sustainable level for future generations. The biological parameters used were L = 155 mm, K = 0.22 and M = 0.22. The yield per recruit model suggests that to maximize yield it is necessary to increase the size of first capture to 105 mm with fishing mortality close to 0.65. The results of the dynamic optimization model indicated that the size of optimum catch and cohort biomass decrease as the discount rate increases, and this is reflected in a reduction of the yields. For discount rates lower than 5%, which is recommended for this fishery, the size of optimum catch is located between 110 and 116 mm. Both models suggest that the minimum legal size established by the Ministry of Natural Resources, Environment and Fishing (SEMARNAP) of 80 mm for the red sea urchin is below the size that allows obtaining optimal gains. In order to obtain large catches in the long term and to maximize the economical profits it is necessary to increase the size of first capture to 110 mm. For the discount rate of 0% a time interval was calculated in which fishing takes place with a maximum rate. The results indicate that the fishing season can be reduced from eight to four months.