A computer model to predict salmonid fry emergence

摘要

The salmonid fry emergence computer model was developed to determine fry survival and emergence as a function of physical parameters in the redd. The criteria in the percent fry emergence model were developed to reflect average habitat requirements that will provide realistic estiamtes of percent fry emergence. The model is applicable to rainbow trout (Oncorhynchus mykiss), steelhead trout (O. mykiss), and chinook salmon (O. tshawytscha), However, the concepts should be applicable to salmonid species, in general, after making the appropriate modifications for the species of interest. The models uses a binary criterion for survival due to temperature and dissolved oxygen with mortality calculated for the proportion of gggs exposed to lethal levels. The only physical parameter that fractional emergence values are derived from i ssubstrate size and composition. This is a reflection of the amount of entrapment experienced by the emerging fry. Model predictive equations and survival criteria were incorporated into a Fortran 77 program.