Effects of stochasticity and social norms on complex dynamics of fisheries

TL;DR

This study investigates how stochasticity and social norms influence the dynamics of recreational fisheries, revealing critical transitions and potential mitigation strategies through a stochastic social-ecological model.

Contribution

It introduces a stochastic two-species fish model incorporating social norms, providing new insights into critical transitions and resilience in fisheries management.

Findings

Increased harvesting rate causes a shift from high-yield to low-yield fisheries.

Social norms help maintain moderate fish densities despite high harvesting.

Indicators can forecast sudden critical transitions.

Abstract

Recreational fishing is a highly socio-ecological process. Although recreational fisheries are self-regulating and resilient, changing anthropogenic pressure drives these fisheries to overharvest and collapse. Here, we evaluate the effect of demographic and environmental stochasticity for a social-ecological two-species fish model. In the presence of noise, we find that an increase in harvesting rate drives a critical transition from high-yield/low-price fisheries to low-yield/high-price fisheries. To calculate stochastic trajectories for demographic noise, we derive the master equation corresponding to the model and perform Monte-Carlo simulation. Moreover, the analysis of probabilistic potential and mean first-passage time reveals the resilience of alternative steady states. We also describe the efficacy of a few generic indicators in forecasting sudden transitions. Furthermore, we show that incorporating social norms on the model allows moderate fish density to maintain despite higher harvesting rates. Overall, our study highlights the occurrence of critical transitions in a stochastic social-ecological model and suggests ways to mitigate them.