BIOECONOMIC MODELLING FOR FISH BIODIVERSITY AND PROFITABILITY

The problem of water pollution, loss of biodiversity and its impact on fish harvest has been modelled in an aggregated Gordon-Schaefer model for the Digha fishery of West Bengal, India. An economic biodiversity index and an environmental quality variable have been included and the parameters are estimated using Schnute method. This exercise focuses on the dynamics of the profit- maximising regime and explores the dynamic maximum economic yield and maximized net present-value of fishery profit. Small perturbations in discount rate and intrinsic growth rate have been done as part of sensitivity analysis and their impact on optimal profit has been examined under different economic biodiversity scenarios. Results show that policymakers have to be careful while framing policies involving trade-offs between the development of fishing activities and the thriving tourism in Digha. Our analysis finds that in the Digha fishery there exists a trade-off between economic biodiversity conservation and profit maximization.