Abstract: A new method, the “dynamic response method,” was developed (DeMaster et al. 1982) in an attempt to use time series data on relative population sizes to satisfy the requirements of the Marine Mammal Protection Act of 1972 for maintaining an “optimum sustainable population” of marine mammals. Three methods of implementing this approach were studied, using a computer simulation of stochastic population growth with density-dependence operating on first-year survival in the form of a generalized-logistic function. Methods developed by Gerrodette (1988) and Boveng et al. (1988) appeared to be less sensitive than desirable when used with the simulated population data. The third method, developed in this study, offers better protection against “Type II error” (failing to identify populations in the optimum sustainable population range), particularly when combined with Gerrodette's (1988) approach.