The effect of anthropogenic and environmental factors in coupled human‐natural systems: Evidence from Lake Zürich

Abstract

AbstractExploiting a rich data set including both individual fishing activities and ecology, we study how eutrophication and climate warming influence plankton biodiversity in Lake Zürich and the consequent effects on fishers’ behavior and fishery yield. Our analysis indicates that changes in the fishery of Lake Zürich were driven by complex dynamic interactions between fishing efforts, environmental conditions, and lake ecosystem ecology. Results show that nutrient levels and climate warming have both direct and indirect dynamic and nonlinear effects on both fishers’ behavior and lake productivity. Ecological factors such as plankton abundance and diversity affect the dynamics of the fish population, which, in turn, influences fishing effort. The analysis highlights the importance and the interdependence of ecological‐human linkages in aquatic ecosystems.Recommendations for Resource Managers This model estimates and simulates the effects of temperature and nutrients on the ecology and the management of a commercial lake fishery. Natural and anthropogenic factors have both direct and indirect effects on fishing intensity and the dynamics of lake productivity. In the long term, increasing phosphorus has negative impacts on the plankton of the lake; higher nitrogen has a positive impact on zoo‐abundance, but a negative impact on zoo‐richness; higher temperatures have positive effects on phytoplankton. Considerable heterogeneity exists in both in lake ecology at different habitats (top vs. bottom of the lake) and behavioral response (pelagic nets vs. demersal nets) to environmental fluctuations.