FISH POPULATION STUDIES , LEWIS AND CLARK LAKE, MISSOURI RIVER, 1956-62 



By 



Charles H. Walburg 

 Fishery Research Biologist 

 North Central Reservoir Investigations, 

 Yankton, South Dakota 



ABSTRACT 



Studies on 33, 000 -acre Lewis and Clark Lake, a mainstem Missouri 

 River reservoir, during the first 7 years of impoundment (1956-62) indicate 

 that carp, river carpsucker, and white crappie were the most abundant 

 fishes . Other major species (listed phylogenetically) were shovelnose 

 sturgeon, shortnose gar, smallmouth buffalo, channel catfish, black crappie, 

 sauger, and freshwater drum. Relative abundance estimates, based on 

 experimental gill net, frame net, and shore seine catches in the months of 

 June, July, and August by South Dakota Department of Game, Fish, and 

 Parks personnel in years 1956 through 1961, and by Bureau of Sport Fisheries 

 and Wildlife personnel in 1962, suggest that total numbers of most species 

 have declined since 1956. Fish reproduction and growth rates have also 

 declined during the same period. Young-of -the -year gizzard shad were the 

 dominant forage fish. The silvery minnow, abundant following impoundment, 

 was replaced by the emerald shiner. 



Lewis and Clark Lake was formed by the 

 closure of Gavins Point Dam in July 1955 . This 

 reservoir, located on the Missouri River in south- 

 eastern South Dakota, forms a part of the bound- 

 ary between the States of South Dakota and Nebras- 

 ka. It is the smallest and southernmost of six 

 mainstem reservoirs constructed by the U.S. 

 Army Corps of Engineers in a comprehensive 

 plan for flood control and other purposes in the 

 Missouri River Basin. 



Studies on the fish population of this reservoir 

 were initiated in 1956 by the South Dakota Depart - 

 ment of Game, Fish and Parks, and continued 

 each year through 1961 as part of the Dingell- 

 Johnson Federal aid to fish restoration program 

 (projects F-l-R-6 through 11). The objective of 

 these studies was to document the development 

 of the fish population and suggest possible 

 management techniques I/. 



In 1962 the North Central Reservoir Inves- 

 tigations, Bureau of Sport Fisheries and Wild- 

 life, began studies on Lewis and Clark Lake. 

 Trie objective of this investigation is to relate 

 long-term water management operations of the 

 Missouri River reservoirs to their fish popu- 

 lations. This will be accomplished by compre- 

 hensive fishery and limnological studies. With 

 this information it should be possible to predict 

 how different types of water management will 

 influence a fish population so that reservoirs 

 can be operated for greater benefit to sport 

 fishing. Initial studies are being conducted on 

 Lewis and Clark Lake, but future work will in- 

 clude other Missouri River Basin reservoirs. 



This paper summarizes the results of 

 studies conducted in Lewis and Clark Lake 

 since formation of the reservoir and follows 

 the development of the fish population through 



j_/^hields, James T. 1957. Report of fisheries investigations during the second year of impoundment 

 of Gavins Point Reservoir, S. Dak., 1956. Dingell -Johnson Project F-l-R-6, 34 pp. (Mimeo.) 



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