This animation is a plan view (down from above) of the full 184-m stream reach model. Habitat cells are shaded by water velocity- brighter cells have higher velocity. Flow is from right to left. The blue line segments are individual trout, and segment length represents trout size. Fish in each cell are displayed from top to bottom in order of decreasing length. A population of 870 age 0 through 2 trout is simulated.
A typical flood flow is simulated, with flows rising rapidly over three days then receding gradually. The animation automatically replays when finished.
In this MG simulation, trout respond to increasing flow by moving to cells (typically along the stream margin) with lower velocities. This response is because food intake and growth decrease at above-optimal velocities. The response is clearest in the riffle-pool sequence at the right (upstream) end of the reach.