Biological Survey — Erie-Xiagara Watershed 57 



per cubic centimeter of water tested. B. Coli or aerogenes were 

 not found in one-tenth or one cubic centimeter amounts of any 

 of the samples tested. Members of B. Coli-aerogenes group were 

 present in 20 of 470 of ten cubic centimeter amounts. 



The bacteriological condition of Lake Erie is never constant 

 but subject to fluctuations due not only to seasonal changes, but 

 following heavy storms at any time during the year, particularly 

 Avhen preceded by heavy rains, the records showing that such dis- 

 turbances have occurred as late as the month of December. How- 

 ever, in the light of available evidence, the lake is remarkably free 

 from pollution and from the bacteriological standpoint, in the 



Preparing cultures on Shearwater 



area investigated, is not a factor in the destruction of either young 

 or adult fish. 



Regarding adult fish, there is no evidence to suspect l)acterial 

 infection of an epidemiological nature in Lake Erie. Such a 



