Pacific salmon populations have discrete breeding cycles in which they return from the ocean to streams to reproduce and then die. This occurs once every one to five years, depending on the species. a) Suppose that each fish must survive predation while streaming upstream, and that predation occurs such that the fraction of that are lost is d. After surviving the upstream swim, assume that each fish produces b offspring before dying. The stream is then stocked with m additionally newly hatched fish before all fish then swim out to sea. What is the discrete-time recursion for the fish population size, assuming there is no mortality at sea? You should count the fish population immediately before the upstream journey. b) Suppose that predation occurs only while the fish are swimming downstream. What is the discrete-time recursion for the fish population dynamics? Again, assumming no mortality at sea. c) Find the equilibria of your results for parts a and b