Michigan Department of Natural Resources
Fisheries Research Report No.1817, 1974
Stability of Residence Among Brown Trout and Rainbow Trout in Experimental Sections
of The Platte River
Clarence M. Taube
Abstract.-An investigation of residence stability and movement of trout was carried out in conjunction with research on competition between trout and coho salmon in Platte River. The study was made mainly in three 1-mile experimental sections that were routinely inventoried in April and September to estimate the numbers of trout and salmon present. In the September 1969 survey, a large number of brown trout (3,788) and rainbow trout (2,734) were fin clipped. The whereabouts of these marked fish was observed on subsequent population surveys. Invariably, many more marked brown trout were found in the section in which they had been fin clipped than were found in the other sections. This situation applied also to rainbow trout on the first inspection (7 months after marking), but thereafter rainbow trout that reached the smolt stage of life migrated to Lake Michigan, and those that remained in the river moved about more. Residence location of brown trout in Platte River is quite stable, which will assist appraisal of competition between salmon and trout. Although the rainbow trout is more mobile, perhaps its mobility will not hinder appraisal because this species resides in the river a comparatively short time.