2/8 Roosevelt Wild Life Bulletin 



ently numerous to be pointed to with pride in the Commissioner's 

 reports. However, subsequent reports ignored the fish, or gave it 

 only passing mention, for the reason that it was merely a repetition 

 of the condition exhibited by the first mentioned fish, with the added 

 fact, perhaps, that some other inhabitant of the waters was extermi- 

 nated. 



The size attained by any species depends largely upon the quantity 

 and quality of its food supply, and having sufficient time in which 

 to grow. In the same length of time, other things being equal, some 

 species attain a larger size than other species do. In other words 

 they grow faster. The number of fish that can be produced and 

 maintained hangs on the favorableness of the waters in every way, 

 the number planted, and the number removed. When a body of 

 water is stocked to its maximum limit, only a comparatively few 

 will attain a large size. 



It is self evident that a limited bod}^ of water cannot afford an 

 unlimited fish supply for an unlimited number of anglers, which 

 judging from some operations, seems to have been thought possible. 

 Every body of water is probably capable of being made to sup- 

 port more life than it did in a state of nature, but any attempt to 

 make it do so is attended with danger. It must be intelligent action, 

 based upon exact knowledge. 



In an article by R. L. Barney and H. L. Canfield r'22), a state- 

 ment is made which applies to natural waters as well as to farm 

 fish-ponds : " The tendency in stocking new ponds or in restocking 

 old ones seems to be toward overstocking. Evidence discussed here- 

 with suggests that, for a pond to gain production of edible-sized fish 

 and still contain a regular large annual production, it must not be 

 overstocked." And, again, a note in " Fisheries Service Bulletin " 

 (U. S. Bureau of Fisheries. ]March i, 1923, No. 94), referring to 

 production of the Fairport Farm Pond, says : " It has been observed 

 that too great a production of young fish in a given year prevents 

 many of the half grown fish from attaining edible size through too 

 serious competition for the available food." 



Overstocking may be effected in two ways : (i ) by introduction 

 of too manv kinds of fish, and (2) by planting too many fish of 

 any kind. 



Before stocking a body of water, it is necessary to ascertain the 

 actual conditions, both favorable and unfavorable, and to determine, 

 to use a life insurance term, " the expectation." We may judge, 

 if a stream or lake has supported certain kinds of fish, that, the 

 conditions being unchanged, it is again capable of doing so. How- 

 ever, careful consideration is required to make sure that the condi- 

 tions have not changed and to reach a positive or exact decision 

 respecting the number of individuals the water will support, or, if 

 the conditions have greatly changed, to ascertain to how many and to 

 what kinds of fishes the waters are adapted. In this connection, it 

 should be stated that because certain fishes appear to be of no utility 

 as food or game fish, or because the}' are predacious fishes commonly 

 designated as fish enemies, and of little value for food or game 



