Thirty-one large buffaloes were taken. These were of two species, the redmouth buffalo, 

 Megas i,omatobus cyprinella (Valenciennes), ana the mongrel or black buffalo, Ictiobus niger 

 (Raf Inesque) . Only five black buffaloes were observed by the author; buffaloes were not identified 

 as to species In the seining preceding the poisoning. Some of the buffaloes were extremely large — 

 11 fish ranged from 26 to 40 pounds in weight; the smallest fish In the group that survived the 

 winterkill of 1944-45 weighed 10.5 pounds. 



R)ur hundred twenty-four small buffaloes were collected and all were redmouths. These fish 

 were relatively uniform In size and most of them weighed between 1.4 and 2.0 pounds each. There was 

 no evidence of a successful buffalo spawn In 1946. 



Approximately 8,500 golden shiners were taken In the census; these were all relatively 

 small, averaging 3.0 Inches In length. No large adult shiners, such as are occasionally found In 

 artificial lakes, were seen. It Is possible that adults survived the winterkill of 1944-46 but died 

 following the 1946 spawning season. Otherwise, It Is Impossible to account for the large number of 

 young shiners. 



DISCUSSION 



The fish population of Oale Lake as shown by the 1946 census clearly Illustrated a number 

 of points associated with winterkill of fishes: 



(1) Under winterkill conditions, the mortality rate of fishes may be high, but usually It 

 Is not 100 per cent; that Is, while the bulk of the fish population In a lake may die as a result of 

 oxygen deficiencies under Ice, a few fishes usually manage to survive. 



(2) It Is lii5)osslble to predict the survival of fishes inder winterkill conditions. As is 

 well known, some species are more tolerant of low oxygen tensions than others. Although, as a gen- 

 eral rule, those that are most tolerant are most likely to survive, survival rate is not always pro- 

 portional to tolerance. Apparently, unfavorable conditions are not uniform througjiout a body of 

 water, and It Is possible that, where fishes are concentrated In some localized areas, all of them 

 may die, while scattered Individuals away from these concentrations may survive. 



(3) No matter what kinds and numbers of fishes survive a partial winterkill, the replace- 

 ment population (after the survivors have spavmed) Is radically different. In relative numbers of 

 individual species, from the population Just previous to the winterkill. This change Is usually un- 

 favorable for angling. 



(4) The survival of spawn Is high In the fish population thinned by winterkill, with the 

 result that, after approximately one spawn and me growing season, the lake again supports a fish 

 population equal In total weight to the carrying capacity of the water. 



8 



