Model for the movement and distribution of fish in a body of water

Abstract

A Monte Carlo mathematical model tracks the movement of fish in a body of water (e.g., a pond or reservoir) which is represented by a two-dimensional grid. For the case of a long, narrow reservoir, depth and length along the reservoir are the logical choices for coordinate axes. In the model, it is assumed that the movement of fish is influenced by gradients of temperature and dissolved oxygen, as well as food availability and habitat preference. The fish takes one spatial ''step'' at a time, the direction being randomly selected, but also biased by the above factors. In trial simulations, a large number of simulated fish were allowed to distribute themselves in a hypothetical body of water. Assuming only temperature was influencing the movements of the fish, the resultant distributions are compared with experimental data on temperature preferences.