This model shows two species of sharks, white tip sharks (WTS) and black tip sharks (BTS) competing for the same resources. This model is similar to an unconstrained population model, with births, deaths, a death rate and no carrying capacity. The growth of individual shark populations is constrained by the growth of the other population. If the WTS experience a lot of growth, then there are fewer resources for the BTS and their population will shrink, and vice versa. Let's take a look at how this works.
Population Stocks: The white tip shark and black tip shark populations are controlled by the WTS Init and BTS Init sliders. Both the WTS and BTS stocks have birth and death flows in and out of the stocks. Birth rate and death rate flows are fed by terms controlled by sliders. Pretty simple, right? The graph shows what happens to each of the populations. Play around with various settings. See what happens when you vary birth rate, initial population, and death rate.