Age, growth, and mortality of Opisthonema libertate on the coasts of northwestern Mexico

Autor: Casimiro Quiñonez-Velázquez, Marcelino Ruiz-Domínguez
Rok vydání: 2018
Předmět:
Zdroj: Ciencias Marinas. 44
ISSN: 2395-9053
0185-3880
Popis: espanolA partir de la lectura de 1,214 otolitos de sardinas crinudas (Opisthonema libertate) procedentes de 3 zonas de pesca en las costas noroccidentales de Mexico (bahia Magdalena, Baja California Sur; Mazatlan, Sinaloa; y Guaymas, Sonora), se asigno la edad y se estimaron los parametros de crecimiento individual, la mortalidad y la tasa de explotacion. Se leyeron hasta 5 marcas de crecimiento en los otolitos y se asig-naron 6 grupos de edad (0–5). Las marcas de crecimiento mostraron periodicidad anual. Al conjunto de datos de edad/talla se agregaron datos de 74 larvas (criadas en el laboratorio desde la eclosion hasta los 24 d de edad) y datos de 96 juveniles (recolectados del ambiente natural con edad de entre 48 y 210 d). Para describir el crecimiento de la sardina crinuda, se uso un enfoque multimodelo. Cinco modelos fueron evaluados y su pertinencia se jerarquizo de acuerdo con el criterio de informacion de Akaike. Para las 3 zonas de pesca, el modelo mas adecuado fue el de von Bertalanffy. Las estimaciones de los parametros (longitud maxima teorica [L∞], coeficiente de crecimiento [k] y la edad a la longitud cero [t0]) fueron L∞ = 18.68, k = 1.13 y t0 = –0.03 para bahia Magdalena; L∞ = 18.63, k = 1.41 y t0 = –0.02 para Mazatlan; y L∞ = 18.22, k = 1.44 y t0 = –0.002 para Guaymas. Las diferencias entre los estimadores entre zonas de pesca fueron significativas (prueba de tasa de verosimilitud). La mortalidad total (Z), la mortalidad natural (M) y la tasa de explotacion (E) por zona de pesca fueron las siguientes: M = 0.6, Z = 1.93 y E = 0.7 para bahia Magdalena; M = 0.6, Z = 1.39 y E = 0.6) para Mazatlan; y M = 0.6, Z = 1.4 y E = 0.6 para Guaymas. Los resultados sugieren que la poblacion de O. libertate en la costa noroccidental de Mexico no muestra indicios de sobreexplotacion. EnglishUsing readings of 1,214 Pacific thread herring (Opisthonema libertate) otoliths collected at 3 fishing locations off the north-western coasts of Mexico (Bahia Magdalena, Baja California Sur; Mazatlan, Sinaloa; and Guaymas, Sonora), age was assigned and individual growth parameters, mortality, and exploitation rates were estimated. Up to 5 growth marks were read on otoliths and 6 age groups (0–5) were assigned. Growth marks showed annual periodicity. The age–size data set was supplemented with data of 74 larvae (reared in the laboratory from hatchling to 24 d of age) and data of 96 juveniles (collected from the natural environment, between 48 and 210 d of age). A multi-model approach was used to describe the growth of the Pacific thread herring. Five models were evaluated and their appropriateness was ranked according to the Akaike information criterion. The von Bertalanffy model was the most appropriate model for the 3 fishing areas. Parameter estimates (theoretical maximum length [L∞], growth coefficient [k], and age at zero length [t0]) were L∞ = 18.68, k = 1.13, and t0 = –0.03 for Bahia Magdalena; L∞ = 18.63, k = 1.41, and t0 = –0.02 for Mazatlan; and L∞ = 18.22, k = 1.44, and t0 = –0.002 for Guaymas. The differences between estimators by fishing area were significant (likelihood ratio test). Total mortality (Z), natural mortality (M), and the exploitation rate (E) by fishing area were as follows: M = 0.6, Z = 1.93, and E = 0.7 for Bahia Magdalena; M = 0.6, Z = 1.39, and E = 0.6 for Mazatlan; and M = 0.6, Z = 1.4, and E = 0.6 for Guaymas. Results suggest that the O. libertate population off the northwestern coasts of Mexico does not show signs of overexploitation.
Databáze: OpenAIRE
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