Algorithms for simulating the response of a benthic animal community and several abiotic environmental variables to organic pollution are described. An IBM PC compatible computer program incorporating these methods has been written. The program simulates the abundance response of 23 species, the redox potential depth profile and several other sediment variables at any distance from a point source of pollution. The program has been designed as a teaching tool and examples of its use to study pollution biology and biometrics are given.