for the Pre-Spill Period, 1980-1989

Ealancing of the model required few steps that went beyond the available data; nevertheless, the model is preliminary in that additional ecological information is available on PWS and the functional groups of the organisms therein. Much of this information is not yet incorporated in the model. However, the purpose of this model is to serve as basis for further work, illustrated in two authored appendices, one showing the close match between the trophic levels estimated by the models and estimates based on stable isotope ratios, and the other documenting how inferences on the dynamics of PWS may be derived from its static representation. A mass-balance model of trophic interactions among the key functional groups of Prince William Sound (PWS), Alaska, is presented, based mainly on published data referring to the period from 1980 to 1989, before the Exxon Valdez oil