MODELING THE OCEANIC FOOD-WEB USING A QUASI-STEADY-STATE APPROACH

In aquatic food web models one is often interested in the long-term av erage (or expected) values of the model-outputs rather than the actual dynamical solution. In this paper an aquatic food web model is analys ed by comparing a dynamical solution of the system equations with a qu asi steady-state solution, which is defined as the series of (potentia l) steady states that correspond to the inputs and boundary conditions at each particular time. Although the system is never actually in (or even near) steady state, it appears that the yearly averaged values o f the variables are similar for dynamical and quasi steady-state solut ions. This conclusion is robust for a wide range of parameter values. A practical implication of this result is an increase in computational efficiency. A theoretical implication is that it shows the relevance of steady-state analysis, which may result in a considerable model sim plification without appreciable loss in accuracy.