In mixed fisheries where there is an increased ecological interdependence between two or more target species, the possibilities of fishing these species must be determined jointly, since catches of one species will im...In mixed fisheries where there is an increased ecological interdependence between two or more target species, the possibilities of fishing these species must be determined jointly, since catches of one species will impact the natural growth not only of that species but of the others, as well. The objective of this paper is to develop a predator-prey model for two major species caught by the EU fishing fleet on European Union fishing grounds. The predator and prey’s population dynamics follow the Lotka-Volterra equation and are assumed to be logic-based, and a lineal interaction between the predator and prey populations is assumed. Optimal single owner multispecies fishery management is analysed, and the applied model is solved, obtaining the equilibrium value of biomasses, catches, and net benefits of the mixed fishery. The results show that the MSY of the predator is higher than that estimated by ICES, while MSY for prey is lower. The sensitivity analysis of the results reveals that the biomass levels of both species decrease as the discount rate increases, while catches increase.展开更多
This study investigates metal and metalloid accumulation and evaluates the associated human health risks in meagre(Argyrosomus regius),European hake(Merluccius merluccius),and sand sole(Pegusa lascaris)obtained from f...This study investigates metal and metalloid accumulation and evaluates the associated human health risks in meagre(Argyrosomus regius),European hake(Merluccius merluccius),and sand sole(Pegusa lascaris)obtained from fish markets and supermarkets in three major northeastern Mediterranean cities(Adana,Antalya,and Mersin).Seasonal samples were collected,and metal concentrations in muscle tissues were quantified using Inductively Coupled Plasma Mass Spectrometry.The mean concentrations of the analyzed metals,expressed as mg kg^(-1) wet weight,ranged as follows:selenium(Se),0.67-2.01;mercury(Hg),0.00-0.71;chromium(Cr),0.23-1.13;lead(Pb),0.02-0.43;cadmium(Cd),0.01-0.09;and inorganic arsenic(iAs),0.00-0.27.The results were evaluated under different consumption scenarios(1/3/5 days/week,20/60/100 g/day)for adults(70 kg body weight)and children(32 kg body weight).Estimated Weekly Intakes(EWI)were calculated and compared with the Provi-sional Tolerable Weekly Intake(PTWI)limits established for each metal.Target Hazard Quotients(THQ),Life-time Cancer Risk(CR),and Selenium Health Benefit Values(HBVSe)were also assessed.Overall,the EWI and HBVSe values for all species fell within safe limits.While THQ values for adults remained within acceptable thresholds,THQ(Hg),THQ(Cr),THQ(iAs),TTHQ,CR(Cr),and CR(iAs)values indicated potential health risks for children under high-consumption scenarios.In conclusion,the results highlight generally low health risks for adults but indicate potential concerns for children under high-frequency consumption scenarios.展开更多
文摘In mixed fisheries where there is an increased ecological interdependence between two or more target species, the possibilities of fishing these species must be determined jointly, since catches of one species will impact the natural growth not only of that species but of the others, as well. The objective of this paper is to develop a predator-prey model for two major species caught by the EU fishing fleet on European Union fishing grounds. The predator and prey’s population dynamics follow the Lotka-Volterra equation and are assumed to be logic-based, and a lineal interaction between the predator and prey populations is assumed. Optimal single owner multispecies fishery management is analysed, and the applied model is solved, obtaining the equilibrium value of biomasses, catches, and net benefits of the mixed fishery. The results show that the MSY of the predator is higher than that estimated by ICES, while MSY for prey is lower. The sensitivity analysis of the results reveals that the biomass levels of both species decrease as the discount rate increases, while catches increase.
基金supported by the Scientific Research Projects Coor-dination Unit of Cukurova University[Project number:FBA-2020-13010].
文摘This study investigates metal and metalloid accumulation and evaluates the associated human health risks in meagre(Argyrosomus regius),European hake(Merluccius merluccius),and sand sole(Pegusa lascaris)obtained from fish markets and supermarkets in three major northeastern Mediterranean cities(Adana,Antalya,and Mersin).Seasonal samples were collected,and metal concentrations in muscle tissues were quantified using Inductively Coupled Plasma Mass Spectrometry.The mean concentrations of the analyzed metals,expressed as mg kg^(-1) wet weight,ranged as follows:selenium(Se),0.67-2.01;mercury(Hg),0.00-0.71;chromium(Cr),0.23-1.13;lead(Pb),0.02-0.43;cadmium(Cd),0.01-0.09;and inorganic arsenic(iAs),0.00-0.27.The results were evaluated under different consumption scenarios(1/3/5 days/week,20/60/100 g/day)for adults(70 kg body weight)and children(32 kg body weight).Estimated Weekly Intakes(EWI)were calculated and compared with the Provi-sional Tolerable Weekly Intake(PTWI)limits established for each metal.Target Hazard Quotients(THQ),Life-time Cancer Risk(CR),and Selenium Health Benefit Values(HBVSe)were also assessed.Overall,the EWI and HBVSe values for all species fell within safe limits.While THQ values for adults remained within acceptable thresholds,THQ(Hg),THQ(Cr),THQ(iAs),TTHQ,CR(Cr),and CR(iAs)values indicated potential health risks for children under high-consumption scenarios.In conclusion,the results highlight generally low health risks for adults but indicate potential concerns for children under high-frequency consumption scenarios.
