Modelling Through

An ecosystem is a system, and if it is ailing, as ours seems to be, the course of treatment begins with a good dose of systems analysis. There is consequently in progress a very large effort to construct and interpret systems analytic models of ecosystems from the Delaware Estuary to San Francisco Bay and beyond. This paper will review the general features of such ecosystem models. Special emphasis will be laid on their limitations, since it is only by facing these limitations candidly that we shall be led to direct our attention to the critical defects that have to be overcome before the models can be accepted as trustworthy guides to decisions.