Two-species model for spatial distributions of sardine and anchovy: A comparison with real data

Abstract

We present a study of pattern formation in a set of two coupled equations modeling two competing species. We consider generalized Lotka-Volterra equations in the presence of a multiplicative noise which models the interaction between the species and the environment. The interaction parameter between the species is a random process which obeys a stochastic differential equation with a generalized bistable potential in the presence of a periodic driving term, which accounts for the environment temperature variation.We find noise-induced spatial patterns with strong anti-correlation between the two species. We compare our theoretical results with the experimental data of the spatial distributions of anchovy and sardine abundances collected during an oceanographic campaign in the Strait of Sicily. Preliminary analysis show qualitative agreement between theoretical and experimental results.