Suppose that a healthy population of some species is growing in a limited environment and that the current population P₀ is fairly close to the carrying capacity M₀. You might imagine a population of fish living in a freshwater lake in a wilderness area. Suddenly a catastrophe such as the Mount St. Helens volcanic eruption contaminates the lake and destroys a significant part of the food and oxygen on which the fish depend. The result is a new environment with a carrying capacity M₁ considerably less than M₀ and, in fact, less than the current population P₀. Starting at some time before the catastrophe, sketch a “before-and-after” curve that shows how the fish population responds to the change in environment.