Optimal Harvesting of an Age-Structured Schooling Fishery

摘要: Biologists have criticized traditional biomass models in fishery economics for being oversimplified. Biological stock assessment are more sophisticated with regard to biological content, but rarely account economic objectives. This study includes a full age-structured population model studying schooling fisheries and extends the delayed difference approach used earlier studies. We take total harvest as choice variable, resulting simple analytical structure. The produces optimal steady states that may be higher or lower compared to delayed-difference formulation. is applied Baltic sprat fishery. Both ecological harvesting cost data support specifying Given nonlinear costs, solution path toward state smooth annual age Sensitivity analysis shows highly dependent on level of the sprat’s main predator cod. A linear function an interest rate below 9% imply pulse fishing instead continuous harvesting. cost, yield rather insensitive changes rate. However, under high cod scenario, rates 10% implies no exists.