Method to obtain abundance indices in the population of Farfantepenaeus californiensis (Holmes, 1900) from the Gulf of Tehuantepec, Oaxaca, Mexico

• Published in: Revista de biología marina y oceanografía 2008-04, Vol.43 (1), p.111-119
• Main Author: Cervantes Hernández, Pedro
• Format: Article
• Language: English
• Subjects: annual variation; Brown shrimp; Camarón café; Mexican Pacific; Pacífico mexicano; reclutas; recruits; reproductores; spawners; variación anual
• ISSN: 0717-3326
• DOI: 10.4067/S0718-19572008000100011

A method to model the annual abundance variation of the Farfantepenaeus californiensis (Holmes, 1900) from the Gulf of Tehuantepec, Oaxaca, Mexico is proposed. Principal components analysis (PCA) was used to obtain two population indices: the abundance of recruits, or FR index, and the abundance of spawners, or DR index. The age group of four months was used to calculate the FR index and the age groups from six to 11 months were used to calculate the DR index. The analysis of the fishery mortality rate (F) indicated that shrimp between 12 (F = 0.88 monthly) and 16 months (F = 1.66 monthly) were overfished, and that 3 months old shrimp were observed partially recruited to the fishery (F = 0.02 monthly); for this reason, PCA did not show a significant factor loading in any of the indices. The age groups selected by PCA in each calculated population index were observed underfished in the natural population so that these age groups were considered very important to maintain the continuity of the fishery between 1989 and 1998. Based on the annual abundance variation of FR and DR obtained by the virtual population analysis (VPA), from July to August/September, the abundance of recruits was higher than the spawners, while from October to January, the abundance of spawners was higher than the recruits Se propone un método para modelar la variación anual de la abundancia de Farfantepenaeus californiensis (Holmes, 1900) del Golfo de Tehuantepec, Oaxaca, México. El análisis de componentes principales (ACP) se utilizó para obtener dos índices poblacionales: la abundancia de reclutas o índice FR y la abundancia de reproductores o índice DR. El grupo de cuatro meses de edad se utilizó para calcular el índice FR y los grupos de seis a 11 meses, para calcular el índice DR. El análisis de la tasa de mortalidad por pesca (F) indicó que los camarones entre 12 (F = 0,88 mensual) y 16 meses (F = 1,66 mensual) fueron sobre-explotados, y que los camarones de tres meses de edad se observaron parcialmente reclutados a la pesquería (F = 0,02 mensual); por esta razón, el ACP no generó cargas factoriales significativas en ninguno de los índices. Los grupos de edad seleccionados por el ACP en cada índice estimado, se observaron sub-explotados en la población natural, de modo que, estos grupos de edad fueron considerados importantes para mantener la continuidad de la pesquería entre 1989 y 1998. Con base en la variación anual de la abundancia FR y DR obtenida por el análisis de poblaci