7. Model output animation of response to reduced food availability using the "maximize growth" (MG) movement objective.

 

This animation is a plan view (down from above) of the model stream. Habitat cells are shaded by depth- brighter cells are deeper. Flow is from right to left through this riffle-pool-riffle sequence. The blue line segments are individual adult trout, and segment length represents trout size (except for graphics resolution errors). Fish in each cell are displayed from top to bottom in order of decreasing length.

The simulation is initialized with five trout of nonuniform size. Five initial time steps occur with normal concentrations of drift food, then drift concentration is decreased to 1/3 of normal for the remaining 15 time steps. The animation automatically replays when finished.

In the MG simulation, trout do not respond to the change in food availability because the same cells continue to offer highest growth. Except for an early change in cell by the smallest trout, no movement occurs.
 



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