Fig. 1. Concentrations of the predator D. nasutum (left) and the prey P. aurelia (right) as measured by Veilleux and predicted by the revised model in Table 6.

Fig. 2. Observed water height in Ringkøbing Fjord over a year, along with heights predicted by the revised model.

Fig. 3. Observed phytoplankton and nitrate concentrations in the Ross Sea, along with predictions from the best revised process model, for training (left) and test (right) data.

Fig. 4. Observed phytoplankton and nitrate concentrations in the Ross Sea, along with predictions from the second-best revised model, for training (left) and test (right) data.

Fig. 5. Training and testing errors for best RPM models for Ringkøbing Fjord (left) and the Ross Sea (right) as a function of distance from initial model.

A quantitative process model for the Ross Sea ecosystem

The process model for the Ross Sea ecosystem translated into the traditional notation of differential and algebraic equations

Some generic processes for aquatic ecosystems with type constraints on their variables and range constraints on their parameters

A simple process model for a predator–prey ecosytem

A set of generic processes for predator–prey models

Best revised process model for the predator–prey ecosytem

Initial process model for Ringkøbing Fjord

Additional generic processes for Ringkøbing Fjord