Model results are very sensitive to assumptions regarding future survivals. You can evaluate effects of different assumptions regarding projected survival on stock specific rebuilding schedules by specifying different EV values.
The *.evo file produced during calibration contains (1) stock specific annual age one survival scalars and (2) the estimated EV values as survival projections for all subsequent years.
When Running in scenario mode, the model uses the appropriate value from the file and applies it during the simulation. When run in Monte Carlo mode there are two ways that the model can choose an EV scalar. It can "Bootstrap" the value from the set of values for that stock or it can draw from a distribution of the EV scalars that are fitted to a log normal distribution. The log normal values are assumed to be independent of each other. The form of this sampling is determined by the *.monte file, and the EV values used should be appropriate for the method being chosen.
Two options are available for changing the EV Scalars. Either create separate *.evo files for each option or use dialog box controls for modifying the EV Scalars immediately before running the model.
*.opt file (Line 1) to document the new conditions being modeled. *.opt file so output files can be identified. *.opt file under new file name. *.opt file. *.evo file by using an ASCII text editor. *.evo under new file name. *.evo file name in the *.opt file (Line 9a). *.opt file (Line 1). *.opt file (can include a path). *.opt file under new file name. *.opt file. Look for effects of the change in catch in non-ceilinged fisheries with substantial harvest of the stock or in stock escapement statistics.
The *.enh file has information on changes in enhancement schedules for hatchery and natural supplementation programs. Modifications of the *.enh values can be made either: (1) to incorporate actual changes in the enhancement schedule; (2) to assess possible changes in enhancement. All enhancement changes are relative to average levels during the 1979-1981 base period.
*.opt file (Line 1). *.opt file (Line 9a). *.opt file. *.opt file under new file name. *.opt file. *.enh file using an ASCII text editor. *.enh file under new name. *.opt file (Line 1). *.opt file (Line 9a). *.opt file has the correct "NUMBER OF STOCKS WITH ENHANCEMENT" (Line 21). *.opt file if density dependence is on or off (Line 21a). Enter 1 to indicate that production is considered to be density dependent for natural stocks that are supplemented by hatchery releases. Under most circumstances, this line will read 1. *.enh file name in *.opt file (Line 21b). *.opt file. *.opt file under new file name. *.opt file. *.idl files. The *.idl file contains estimates of pre-spawning survival that occurs after fisheries. Currently, this file only includes estimates of inter-dam loss for Columbia River stocks. Since most inter-dam loss occurs after all fisheries, inter-dam loss is essentially treated as escapement when calculating ocean and terminal area harvest rates. Estimated IDL values are used through the present year, then an average of all estimated values is used for future years.
Changes in estimates of inter-dam loss rates can be assessed by modifying this file. It should be noted, however, that the numbers in the *.idl files are actually estimates of total adult survival past all Columbia River dams.
*.opt file (Line 1). *.opt file (Line 9a). *.opt file. *.opt file under new file name. *.opt file. *.idl file using an ASCII text editor. *.idl file under new name. *.idl file name in the *.opt file (Line 8a). *.opt file (Line 1). *.opt file (Line 9a). *.opt file. *.opt file under new file name. *.opt file.