Maximum net productivity level estimation for the northern fur seal (Callorhinus ursinus) population of St. Paul Island, Alaska

Repetitive simulations are used t.o generate frequency distributions of maximum net productivity level estimates for the northern fur seal population of St. Paul Island, Alaska. Definitive determination of the maximum net productivity level is not possible due to uncertainty in life table parameters and density-dependent change in those parameters. This uncertainty is generally not accounted for in models used to study northern fur seal populat.ion dynamics. The repetitive simulation approach systematically varies simulation input parameters, runs a separate simulation wifh each input parameter combination, and validates the simulations on the basis of comparison with historical observations. Results f rom validated simulations form frequency distributions which provide a measure of confidence for estimates of the maximum net productivity Ievel. These frequency distributions provide a basis for northern fur seal management that is more appropriat.e than single-point estimates, in that they reflect the current, uncertainty regarding northern fur seal life history and density-dependent population regulation. Timothy J. Ragen. "April 1992." "Final report of research conducted 1 October 1990 to 30 April 1991 as National Research Council Fellow at the National Marine Mammal Laboratory, National Marine Fisheries Service." Includes bibliographical references (pages 36-41). 1992 NMFS (National Marine Fisheries Service) AFSC (Alaska Fisheries Science Center) Library Public Domain 1930