Read instructions, get familiar with the model/simulation.
Experiment by increasing the amounts of DDT in the lowest trophic level. Set the speed at one you can control, see how you can make the ‘ticks’ stop and go. Then increase the amount of DDT in the water by increments of 10 ppm (from 10 to 50) , and record the amounts of DDT at every trophic level after a set number of ‘ticks’ – like 200 or 300. How does the DDT buildup in pelicans compare as you increase the level in the water at each level? Is it a straight line relationship, or something different? Explain in several sentences.