250 Roosevelt Wild Life Bulletin 



paratively short shore Hne, the narrowness of the shore area, and 

 the mechanical action of the waves, all tend to limit the growth of 

 rooted plants, hence to limit the productive capacity of the lake 

 in plankton and, according to the current belief, in fishes." 



But in addition to the minute animal food in the water the older 

 fish in general require still other food materials, such as the gross 

 forms living on the bottom. Investigations of their character were 

 long neglected, so that it remained for F. C. Baker ('i6, 'i8) of 

 the New York State College of Forestry, to take up this subject 

 in a quantitative way in his investigation of Oneida Lake. Baker's 

 studies showed very clearly that 88 per cent of the gross invertebrate 

 population, or fish food, was found upon the bottom within the six- 

 foot contour line. It was also found that life was most abundant 

 in sand and the poorest upon boulder bottom. These were the 

 first investigations of the kind in America. About the same time, 

 somewhat similar qualitative studies were made in Lake Mendota, 

 Wisconsin, by Muttkowski ('i8), and very recently the Mollusca 

 have been studied in Lake Nipigon in Canada by Adamstone ('23). 

 The only similar European study was made in Sweden in Lake 

 Vattern by Ekman ('15). (Cf. Baker, '18, .p. 252; also Clemens 

 and others, '23, pp. 171-188.) 



Thus, these studies of the minute and gross fish food (figures 26, 

 27) in the waters will serve as a foundation for future studies which 

 aim to determine the fish food producing capacity of our inland 

 lakes and streams. Such studies must be extended and intensified 

 before we have a really adequate basis for fish culture in public 

 waters. 



We now need intensive study of the habits of the young of all our 

 important fish, in order to know their normal haunts and food as 

 correlated with the normal food supply in our lakes and streams. 

 As Baker ('18, pp. 208-218, 224) pointed out in his study of Oneida 

 Lake, one of the next important steps will be to determine the amount 

 of iish food which fish need for definite periods throughout life. 

 Until this information is secured, as well as the amount of food 

 which a given water can produce, we will remain in the position of 

 a farmer who does not know how much pasture he has or how many 

 cattle he has to be pastured. 



Breeding Grounds. Not only must fish have proper food and 

 proper physical and chemical conditions of the water in order to 

 maintain themselves, but for permanent maintenance there must be 

 available suitable conditions for breeding. The breeding conditions 

 and habitats vary greatly for dififerent kinds of fish. Some deposit 

 their eggs upon gravel shallows in rapid streams, some upon rocky 

 shoals or bars, others upon quiet sandy or gravelly bottoms, and 

 some among vegetation. The great majority, however, breed in 

 shallow waters ; and it is in such conditions that as Baker has shown 

 for Oneida Lake we find the greatest abundance of fish food. This 

 is a significant indication of where certain species of lake and pond 

 fish should be planted. 



