Chaotic dynamics in a multiple species fishery: a model of community predation

A dynamic model of a multiple species fishery that incorporates a community level phenomenon — community predation — indicates that predictable order, the basis of management control of these kinds of multiple species systems, may be found at the system rather than at the individual population level.

Abstract

This paper summarizes a dynamic model of a multiple species fishery that incorporates a community level phenomenon — community predation or the tendency of big fish of almost any species to eat little fish of almost any species. The model is used to explore the conditions under which the dynamic behavior of a multiple species complex characterized by community predation qualitatively conforms with the observed dynamic processes of real fisheries systems. The specifications necessary to replicate qualitatively the dynamic behavior of such system lead to the chaotic behavior of individual populations but stability of the entire system. The presence of chaos may explain why the dynamic path of individual populations in real fisheries has been so resistant to prediction, but more important, indicates that predictable order, the basis of management control of these kinds of multiple species systems, may be found at the system rather than at the individual population level.