This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. Th...This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. The complexity of this system is also analyzed. Moreover, the optimal harvesting policy are given for the inshore subpopulation, which includes the maximum sustainable yield and the corresponding harvesting effort.展开更多
In order to evaluate the regulating effect of ＂ aquatic environment protection oriented fishery＂ on aquatic ecosystem,the water quality,plankton community structure,biomass,diversity index,eutrophication index and e...In order to evaluate the regulating effect of ＂ aquatic environment protection oriented fishery＂ on aquatic ecosystem,the water quality,plankton community structure,biomass,diversity index,eutrophication index and ecosystem maturity evaluated with Ecopath model were compared from 2010 to 2012 in Qiaodun Reservoir of Zhejiang Province. It was indicated that the water quality had been improved obviously. The water transparency maximally increased by 130%,while TP,TN and CODCrwere reduced. The density and biomass of the plankton were decreased,so was the ratio of Cynobacteria in phytoplankton community. The Shannon-Weaver index was increased; the trophic level was decreased; the ecosystem maturity was improved. By all accounts,the ＂ aquatic environment protection oriented fishery＂ had positive effects on maintaining the balance of reservoir ecosystem and ensuring the safety of drinking water.展开更多
Most fisheries in China do not have maximum sustainable yield（MSY） estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch（TAC） for fishery management is ...Most fisheries in China do not have maximum sustainable yield（MSY） estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch（TAC） for fishery management is necessary. MSYs of three important fisheries in the East China Sea were evaluated through a catch-based model.Estimates for intrinsic rate of increase（r） and five levels of process error were considered. Results showed hairtail Trichiurus japonicas（Temminck and Schlegel） and small yellow croaker Larimichthys polyactis（Bleeker） fisheries experienced overfishing from the mid-1990 s to the early 2000 s, and the suggested TACs were 55.8×10^4 t and9.06×10^4 t, respectively. Decades of overfishing in wintering and spawning grounds of large yellow croaker Larimichthys crocea（Richardson） caused the fishery＇s collapse in the 1980 s, and it has not recovered until today.The Catch–MSY model generated similar estimated MSYs with other methods and may be a useful choice for the assessment of regional stocks in China.展开更多
文摘This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. The complexity of this system is also analyzed. Moreover, the optimal harvesting policy are given for the inshore subpopulation, which includes the maximum sustainable yield and the corresponding harvesting effort.
基金Supported by Special Project of Public Welfare Industry(Agriculture)Science Research,Ministry of Agriculture,China(201303056)Zhejiang Standardization Research Project,China(2010-10)
文摘In order to evaluate the regulating effect of ＂ aquatic environment protection oriented fishery＂ on aquatic ecosystem,the water quality,plankton community structure,biomass,diversity index,eutrophication index and ecosystem maturity evaluated with Ecopath model were compared from 2010 to 2012 in Qiaodun Reservoir of Zhejiang Province. It was indicated that the water quality had been improved obviously. The water transparency maximally increased by 130%,while TP,TN and CODCrwere reduced. The density and biomass of the plankton were decreased,so was the ratio of Cynobacteria in phytoplankton community. The Shannon-Weaver index was increased; the trophic level was decreased; the ecosystem maturity was improved. By all accounts,the ＂ aquatic environment protection oriented fishery＂ had positive effects on maintaining the balance of reservoir ecosystem and ensuring the safety of drinking water.
基金The National Natural Science Foundation of China under contract No.31602157the Special Fund for Agroscientific Research in the Public Interest under contract No.201403008the Central Public-interest Scientific Institution Basal Research Fund of South China Sea Fisheries Research Institute under contract No.2016TS06
文摘Most fisheries in China do not have maximum sustainable yield（MSY） estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch（TAC） for fishery management is necessary. MSYs of three important fisheries in the East China Sea were evaluated through a catch-based model.Estimates for intrinsic rate of increase（r） and five levels of process error were considered. Results showed hairtail Trichiurus japonicas（Temminck and Schlegel） and small yellow croaker Larimichthys polyactis（Bleeker） fisheries experienced overfishing from the mid-1990 s to the early 2000 s, and the suggested TACs were 55.8×10^4 t and9.06×10^4 t, respectively. Decades of overfishing in wintering and spawning grounds of large yellow croaker Larimichthys crocea（Richardson） caused the fishery＇s collapse in the 1980 s, and it has not recovered until today.The Catch–MSY model generated similar estimated MSYs with other methods and may be a useful choice for the assessment of regional stocks in China.
