There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population r...There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population resources is increasing. This population is precious protein resource. It is urgent to study how to take prompt and effective fishing and take full advantage of processing,utilization and management. Traditional utilization methods are limited by many factors. The utilization efficiency is extremely low. The feed conversion rate of some mariculture fishes with fresh small trash fishes as feeds is even as low as 0. 2. Innovative production and management organization model with aquatic enterprises as leaders greatly increases the utilization efficiency of small fish resources with the aid of marine processing mother ship. In order to further accelerate developing and utilizing small fishery population resources in coastal and offshore areas,China should launch survey and utilization researches of small fishery population resources in coastal and offshore areas,formulate practical and feasible laws,regulations and policies,actively encourage and support autonomous innovative management mode of enterprises,and promote effective utilization and management of coastal and offshore fishery resources.展开更多
Pakistani marine waters are under an open access regime.Due to poor management and policy implications,blind fishing is continued which may result in ecological as well as economic losses.Thus,it is of utmost importan...Pakistani marine waters are under an open access regime.Due to poor management and policy implications,blind fishing is continued which may result in ecological as well as economic losses.Thus,it is of utmost importance to estimate fishery resources before harvesting.In this study,catch and effort data,1996-2009,of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp.Maximum,minimum and average capture production of P.stylifera was observed as 15 912 metric tons(mt)(1997),9 438 mt(2009) and 11 667 mt/a.Two stock assessment tools viz.CEDA(catch and effort data analysis) and ASPIC(a stock production model incorporating covariates) were used to compute MSY(maximum sustainable yield) of this organism.In CEDA,three surplus production models,Fox,Schaefer and Pella-Tomlinson,along with three error assumptions,log,log normal and gamma,were used.For initial proportion(IP) 0.8,the Fox model computed MSY as 6 858 mt(CV=0.204,R^2=0.709) and 7 384 mt(CV=0.149,R^2=0.72) for log and log normal error assumption respectively.Here,gamma error produced minimization failure.Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log,log normal and gamma error assumptions i.e.7 083 mt,8 209 mt and 7 242 mt correspondingly.The Schafer results showed highest goodness of fit R^2(0.712) values.ASPIC computed MSY,CV,R^2,F_(MSY)and B_(MSY) parameters for the Fox model as 7 219 mt,0.142,0.872,0.111 and 65 280,while for the Logistic model the computed values remained 7 720 mt,0.148,0.868,0.107 and 72 110 correspondingly.Results obtained have shown that P.stylifera has been overexploited.Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.展开更多
文摘There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population resources is increasing. This population is precious protein resource. It is urgent to study how to take prompt and effective fishing and take full advantage of processing,utilization and management. Traditional utilization methods are limited by many factors. The utilization efficiency is extremely low. The feed conversion rate of some mariculture fishes with fresh small trash fishes as feeds is even as low as 0. 2. Innovative production and management organization model with aquatic enterprises as leaders greatly increases the utilization efficiency of small fish resources with the aid of marine processing mother ship. In order to further accelerate developing and utilizing small fishery population resources in coastal and offshore areas,China should launch survey and utilization researches of small fishery population resources in coastal and offshore areas,formulate practical and feasible laws,regulations and policies,actively encourage and support autonomous innovative management mode of enterprises,and promote effective utilization and management of coastal and offshore fishery resources.
基金Supported by the Earmarked Fund for Modern Agro-Industry Technology Research System of Chinathe Special Research Fund of Ocean University of China(No.201022001)
文摘Pakistani marine waters are under an open access regime.Due to poor management and policy implications,blind fishing is continued which may result in ecological as well as economic losses.Thus,it is of utmost importance to estimate fishery resources before harvesting.In this study,catch and effort data,1996-2009,of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp.Maximum,minimum and average capture production of P.stylifera was observed as 15 912 metric tons(mt)(1997),9 438 mt(2009) and 11 667 mt/a.Two stock assessment tools viz.CEDA(catch and effort data analysis) and ASPIC(a stock production model incorporating covariates) were used to compute MSY(maximum sustainable yield) of this organism.In CEDA,three surplus production models,Fox,Schaefer and Pella-Tomlinson,along with three error assumptions,log,log normal and gamma,were used.For initial proportion(IP) 0.8,the Fox model computed MSY as 6 858 mt(CV=0.204,R^2=0.709) and 7 384 mt(CV=0.149,R^2=0.72) for log and log normal error assumption respectively.Here,gamma error produced minimization failure.Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log,log normal and gamma error assumptions i.e.7 083 mt,8 209 mt and 7 242 mt correspondingly.The Schafer results showed highest goodness of fit R^2(0.712) values.ASPIC computed MSY,CV,R^2,F_(MSY)and B_(MSY) parameters for the Fox model as 7 219 mt,0.142,0.872,0.111 and 65 280,while for the Logistic model the computed values remained 7 720 mt,0.148,0.868,0.107 and 72 110 correspondingly.Results obtained have shown that P.stylifera has been overexploited.Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.
