Surplus-production models are widely used in fish stock assessment and fisheries management due to their simplicity and lower data demands than age-structured models such as Virtual Population Analysis. The CEDA (catc...Surplus-production models are widely used in fish stock assessment and fisheries management due to their simplicity and lower data demands than age-structured models such as Virtual Population Analysis. The CEDA (catch-effort data analysis) and ASPIC (a surplus-production model incorporating covariates) computer packages are data-fitting or parameter estimation tools that have been developed to analyze catch-and-effort data using non-equilibrium surplus production models. We applied CEDA and ASPIC to the hairtail (Trichiurus japonicus) fishery in the East China Sea. Both packages produced robust results and yielded similar estimates. In CEDA, the Schaefer surplus production model with log-normal error assumption produced results close to those of ASPIC. CEDA is sensitive to the choice of initial proportion, while ASPIC is not. However, CEDA produced higher R 2 values than ASPIC.展开更多
Largehead hairtail(Trichiurus japonicus)is a commercially important fish species in China Seas,characterized by wide distribution,seasonal migration,spawning all year round.Under long-term high fishing pressure,the bi...Largehead hairtail(Trichiurus japonicus)is a commercially important fish species in China Seas,characterized by wide distribution,seasonal migration,spawning all year round.Under long-term high fishing pressure,the biological traits of largehead hair-tail have changed,such as miniaturization,smaller size-at-age and earlier age-at-maturation.To explore its current biological charac-ters,we analyzed age,growth and maturation of largehead hairtail in the East China Sea by analyzing the otolith microstructure and gonads.The results showed that largehead hairtail is mainly composed of 1 year and 2 years old individuals.The estimated von Ber-talanffy growth function(VBGF)showed significant differences between sexes,and asymptotic pre-anal length of male is longer than that of female.Two spawning seasons were observed in spring and autumn by monthly gonadosomatic index(GSI).Compared to historic survey data,the average pre-anal length at age decreased and size-at-maturation became smaller in the East China Sea.This study updates life history parameters of largehead hairtail,and provides a reference for the present status of largehead hairtail,which can contribute to largehead haritail stock assessment and sustainable utilization in the China Seas.展开更多
基金Supported by the Special Research Fund of Ocean University of China(No. 201022001)
文摘Surplus-production models are widely used in fish stock assessment and fisheries management due to their simplicity and lower data demands than age-structured models such as Virtual Population Analysis. The CEDA (catch-effort data analysis) and ASPIC (a surplus-production model incorporating covariates) computer packages are data-fitting or parameter estimation tools that have been developed to analyze catch-and-effort data using non-equilibrium surplus production models. We applied CEDA and ASPIC to the hairtail (Trichiurus japonicus) fishery in the East China Sea. Both packages produced robust results and yielded similar estimates. In CEDA, the Schaefer surplus production model with log-normal error assumption produced results close to those of ASPIC. CEDA is sensitive to the choice of initial proportion, while ASPIC is not. However, CEDA produced higher R 2 values than ASPIC.
基金supported by the National Key R&D Program of China(No.2018YFD0900902)the Na-tional Natural Science Foundation of China(No.41861134037).
文摘Largehead hairtail(Trichiurus japonicus)is a commercially important fish species in China Seas,characterized by wide distribution,seasonal migration,spawning all year round.Under long-term high fishing pressure,the biological traits of largehead hair-tail have changed,such as miniaturization,smaller size-at-age and earlier age-at-maturation.To explore its current biological charac-ters,we analyzed age,growth and maturation of largehead hairtail in the East China Sea by analyzing the otolith microstructure and gonads.The results showed that largehead hairtail is mainly composed of 1 year and 2 years old individuals.The estimated von Ber-talanffy growth function(VBGF)showed significant differences between sexes,and asymptotic pre-anal length of male is longer than that of female.Two spawning seasons were observed in spring and autumn by monthly gonadosomatic index(GSI).Compared to historic survey data,the average pre-anal length at age decreased and size-at-maturation became smaller in the East China Sea.This study updates life history parameters of largehead hairtail,and provides a reference for the present status of largehead hairtail,which can contribute to largehead haritail stock assessment and sustainable utilization in the China Seas.
