Exploring multistability in marine ecosystems: Insights from food web model dynamics

This review synthesizes the role of multistability in deterministic food web models of marine ecosystems, focusing on how structural features of ordinary differential equation (ODE) models give rise to multiple stable states. From an initial pool of 178 publications, we systematically selected 35 studies that explicitly report multistability in predator–prey and food web models. These were analyzed according to key structural components – such as functional responses, growth and mortality terms, nonlinearities, and network topologies – to identify the mechanisms underpinning the emergence of bistability, tristability, and higher-order multistability.

The reviewed models exhibit a wide range of attractor types, including equilibrium points, limit cycles, and chaotic attractors. Our analysis highlights the influence of non-monotonic functional responses, intraspecific competition, Allee effects, and time-scale separation in generating complex dynamics. Furthermore, we find that bifurcation analysis and numerical simulations are the primary tools used to characterize stability landscapes and attractor transitions.

Despite the advances in modeling techniques, the review reveals a significant gap between theory and empirical application. Most models are general in nature and seldom incorporate real-world species, parameterized data, or specific ecosystem structures. We discuss this gap and propose a collaborative modeling approach focused on keystone species and the development of a shared repository of food web models.

By categorizing multistable behaviors and clarifying their mechanistic origins, this review contributes towards a more robust theoretical foundation for understanding multistability in marine ecosystems.