Importance of Yellowstone River Spawning to Garrison Reservoir 



This spawning run is probably very important for recruitment 

 of walleye into the upper portions of Garrison Reservoir where 

 substrate may not be suitable for walleye reproduction. The upper 

 area of the reservoir is more turbid and silty than the lower 

 reservoir. Walleye usually select substrate characterized by clean 

 rubble or gravel (Nelson and Walburg 1977, Scott and Grossman 

 1973) . Survival of eggs is poor on a silt substrate (Johnson 

 1961). Berard (1980) documented that young-of-year walleye are 

 most abundant in the upper third of Garrison Reservoir. Stewart 

 (1980) found no large seasonal concentrations of walleye in the 

 Missouri River upstream from the mouth of the Yellowstone 

 indicating that the spawning run is limited to the Yellowstone 

 River. Priegel (1970) documented that walleye fry drift into Lake 

 Winnebago from spawning areas in tributaries. As no young-of-year 

 walleye were ever collected in the Yellowstone River, it is assumed 

 virtually all walleye larvae produced in the Yellowstone River 

 drift into the Missouri River (Garrison Reservoir) . Walleye larvae 

 were collected in drift nets from the Yellowstone River downstream 

 from Intake diversion (river km 112) and at Fairview (river km 19) . 

 Immediately after spawning in the Yellowstone walleye return to 

 Garrison Reservoir. Most walleye were recaptured by anglers in the 

 upper one-third of Garrison Reservoir an average distance of 222 km 



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