Review of stock assessment and fishery biology of Dosidicus gigas in the Gulf of California, Mexico

Ontogenetic variation of δ13C and δ15N recorded in the gladius of the jumbo squid Dosidicus gigas: geographic differences

“…200 km over 7 d) recorded for an electronically tagged jumbo squid (Gilly et al 2006). Although D. gigas is believed to migrate for long distances over its entire range (Nesis 1983) or between the Gulf of California and Pacific Ocean (Ehrhardt et al 1983), these migrations have not been observed (Morales-Bojórquez et al 2001). Instead, conventional mark-recapture methods revealed that jumbo squid exhibited seasonal movements between the east and west central Gulf of California (Markaida et al 2005), while electronic tagging showed that squid > 75 cm ML moved in various directions but stayed in the central Gulf (Gilly et al 2006).…”

Stochastic estimation of the catchability and recruitment of the jumbo squid Dosidicus gigas (D'Orbigny, 1835) Of The Gulf Of California, Mexico

“…La influencia de estos eventos en nuestro caso, puede considerarse como una fuente de error asociada al modelo (error de proceso). En este caso, dado que la pesquería está sustentada en una cohorte anual que tiene reclutamiento en mayo (Hernández-Herrera et al, 1998;Nevárez-Martínez et al, 2000), las recomendaciones tienen efecto inmediato sobre la dinámica de la población y sobre la elección de políticas de pesca de este recurso, el cual es principalmente explotado por la flota camaronera como una alternativa rentable (MoralesBojórquez y López-Martínez, 1999;Morales-Bojórquez et al, 2001a).…”

“…The influence of these events, in our case, can be considered as an error source associated to the model (process error). In this case, given that the fishery is sustained in an annual cohort that recruits in May (Hernández-Herrera et al, 1998;Nevárez-Martínez et al, 2000), the recommendations have an immediate effect on the population dynamics and on choosing fishing policies for this resource, which is mainly exploited by the shrimp fleet as a profitable alternative (Morales-Bojórquez and López-Martínez, 1999;Morales-Bojórquez et al, 2001a).…”

“…Dado que el valor estimado de E( CPUE/Ci ) se encontraba fuera de los intervalos de confianza del modelo determinístico, la confrontación de hipótesis de error de proceso vs observación no contribuyó por sí misma a un mejor ajuste del modelo, sin embargo, aportó información sobre la varianza del índice , de la captura y del modelo , mejorando el valor de q a través de E( CPUE/Ci ), lo cual implica que es necesario un mayor conocimiento del error del modelo. De esta manera, podremos comprender mejor el efecto de la pesca , a fin de cumplir de mejor manera con el objetivo de manejo establecido para D. gigas (Nevárez-Martínez y Morales- Hernández-Herrera et al, 1998;Morales-Bojórquez et al, 2001a).…”

“…Given that the estimated value of E( CPUE/Ci ) was out of the deterministic model's confidence intervals, the confrontation of the hypothesis of process error vs observation did not contributed itself to a better fit of the model, nevertheless it provided information about the variances of the index , the catch and the model , improving the value of q through E( CPUE/Ci ), which implies that a better knowledge of the model error is required. Thus, we will be able to better understand, the fishing effect in order to accomplish in a better way, the management objective established for D. gigas Hernández-Herrera et al, 1998;Morales-Bojórquez et al, 2001a).…”