Spawning was usually completed by June 

 15. Age-class distribution of fish collected in 

 1962 suggested that annual reproductive success 

 was erratic (table 16). The 1956 year-class 

 was most abundant, but good reproduction also 

 occurred in 1955 and 1960. Reproductive suc- 

 cess has apparently been weak in most years 

 since impoundment. Comparison of the aver- 

 age length of comparable age fish collected 

 from other areas of the U.S. indicates that 

 growth of the channel catfish in this reservoir 

 was poor (table 16). Average total length of 6- 

 year-old fish collected in 23 Oklahoma reser- 

 voirs was 17.0 inches (Finnell and Jenkins, 1954), 

 while in Lewis and Clark Lake they averaged 

 only 12.9 inches. 



Flathead catfish 



This species was uncommon; few were 

 collected during the 7-year study (table 2). 

 Total length of fish taken in 1962 ranged from 9 

 to 30 inches, and weight ranged from 0.5 to 14 

 pounds. These data suggest a small but relative- 

 ly stable population of this species . 



Blue catfish 



Blue catfish were collected only during the 

 first 2 years of impoundment (table 2). Appar- 

 ent disappearance of this fish suggests that it 

 was unable to adapt to Lewis and Clark reservoir 

 conditions . None was collected in Fort Randall 

 Reservoir after 6 years of intensive netting 

 (Bailey and AUum, 1962). Gavins Point Dam is 

 probably the upstream limit for this species in 

 the Missouri River . 



Stonecat 



Three were collected during the first 2 

 years after impoundment, and none was col- 

 lected since 1958. 



Northern pike 



Only six northern pike were collected dur- 

 ing the 7 years of study (table 2). There was no 

 evidence of survival of the 711,680 fry and fin- 

 gerlings stocked in 1958 (table 1). Early spring 

 water level fluctuations at the time when pike 



usually spawn have probably been unfavorable 

 for reproduction of this species. Studies con- 

 ducted in 1962 indicate that this fish is common 

 in the Missouri River between Fort Randall Dam and 

 the Niobrara River and that few fish move into 

 the reservoir. 



Burbot 



This species was collected only during the 

 first 3 years after impoundment (table 2). Its 

 disappearance suggests that ecological conditions 

 within the reservoir have been unfavorable, since 

 several specimens were collected from the tail- 

 waters of Fort Randall Dam in 1962 . 



White bass 



Between 1959 and 1961 the States of South 

 Dakota and Nebraska introduced 6,470 adult 

 white bass into the reservoir (table 1). This 

 fish was not present in Lewis and Clark Lake 

 prior to 1959. According to Sprague, 4/, the 

 desirability of stocking white bass was thoroughly 

 investigated and available information indicated 

 that it had potential to adapt to conditions exist- 

 ing in the reservoir and could provide good sport 

 fishing without serious detriment to other game 

 species. 



Young-of-the-year were collected by shore 

 seine from 1960 to 1962, and most were taken 

 in 1962 indicating that successful reproduction 

 had occurred (table 7). Adults were first taken 

 in 1962 (table 2), and most were collected in the 

 lower portion of the reservoir . Spawning occurred 

 prior to the middle of June. Most 2-year-old fish 

 were mamre. Lengths of age group I and age 

 group II fish were 5.4 and 11.4 inches, respective- 

 ly. Available evidence suggests that white bass 

 have become firmly established in Lewis and 

 Clark Lake.. 



Green sunfish 



This species was rarely collected in the 

 reservoir . It was more abundant in the first 2 

 years after impoundment than in 1962 (table 2). 



4/ Sprague, James W. 1960. Report of fisheries 

 investigations during the fifth year of impoundment 

 of Gavins Point Reservoir, 1959. Dinge 11 -Johnson 

 Project F-l-R-9, 47 pp. (Mimeo.) 



16 



