Transient and Asymptotic Dynamics of a Bioeconomic Fishery Model with Market Price Fluctuation and Effort Capacity Constraints
摘要
Bioeconomic systems are inherently governed by fast–slow dynamics, arising from the interplay between rapid market adjustments and slower ecological processes. In this paper, we analyze a four-dimensional fishery model that couples predator–prey dynamics with fishing effort subject to capacity constraints and market-clearing prices. Using geometric singular perturbation theory, we show that the separation of timescales leads to a split critical manifold. The system’s operational mode is determined by a single dimensionless bioeconomic parameter, which acts as a structural selector between an Internally-Regulated regime and a Capacity-Saturated regime. Beyond equilibrium stability, we focus on transient behaviors by deriving a closed-form approximation for the transient response time to external shocks. This analytical metric explicitly links recovery duration to the effective net growth budget. Our results demonstrate that while the Capacity-Saturated regime may sustain a stable equilibrium, it incurs significantly larger cumulative ecological deficits and slower recovery rates following perturbations. These findings quantify the trade-off between harvest intensity and system responsiveness, offering a dynamical basis for the vulnerability of high-effort fisheries.