ABSTRACT
The problem of harvesting a population divided into discrete age classes by removing individuals from selective age classes was first investigated by L. P. Lefkovitch. This chapter investigates the analogous problem for a population governed by a continuous-time rather than a discrete-time linear model. The effects of harvesting such a continuous-time population were investigated by F. Brauer and D. A. Sanchez, but not with the purpose of determining the optimal sustainable yield. The chapter shows that if no upper bound is imposed on the harvest rate, then the optimal harvesting policy is impulsive and bimodal; that is, only at most two ages are harvested, with the older being harvest completely. This is analogous to the solution of the discrete-time problem. The chapter discusses an upper bound on the harvest rate and gives a qualitative description of the resulting optimal harvesting policy.
