614 U. S. BUREAU OF FISHERIES 



interrelations of the species so little known that though fish increase, 

 or appear to increase, after extensive plants it can not be positively 

 stated that such increase is due to planting. Enemies of the species 

 mav have decreased or the increase may have been due to natural 

 multiplication. The fact that there are areas where whitefish are 

 said to have increased in recent years without the aid of artificial 

 propagation, and the fact that the sucker, perch, sauger, blue pike, 

 chubs, and herring, in spite of the persecution they have sus- 

 tained, do not make a worse showing in the statistics than the care- 

 fully fostered whitefish and trout, at least justify an attitude of 

 skepticism toward the enthusiastic claims of some of the propaga- 

 tionists. 



At this point it is only fair to state that the leading fish-culturists 

 now regard artificial propagation rather as a supplement to than an 

 improved substitute for nature, but the rank and file of the con- 

 servationists of the Great Lakes area are still influenced by the 

 exuberant optimism of the pioneer fish-culturists, who, inspired Dy the 

 novel achievement of being able to hatch countless fry, entertained 

 rosy visions of the possibilities of the new-found art. This optimism, 

 first and last, arises out of the natural propensity of the human mind 

 to be impressed by figures of inconceivable magnitude. If the 

 hatching of a billion fish eggs is reported in a hatchery bulletin, 

 certainly, one argues, that immense number can not fail to affect the 

 fish supply advantageously; but no statistical bulletins can show what 

 an insignificant fraction of nature's production of fish eggs this huge 

 figure represents, after all, and nowhere is advertised nature's amaz- 

 ing prodigality in dealing with these eggs, though her stupendous care- 

 lessness in this particular can be demonstrated by anyone who is 

 familiar with mathematical progressions. 



Whatever the results of fish hatching on the Great Lakes may 

 be, confidence in the effectiveness of propagation has had most 

 important consequences, and the methods of propagation and the 

 effects of this confidence ouo-ht to be carefully considered. In a vast 

 section of the Great Lakes there is no closed season on any species of 

 fish, and for some, commercial fishing is allowed as soon as 40 per cent 

 of the fish, as shown by test nets, are ripe. The case of the whitefish 

 will serve to illustrate the situation. 



In the year 19 19 one boat which set test nets on the " north grounds " 

 at Alpena took 5,000 pounds of whitefish, practically all males, indi- 

 cating that spawning had not yet begun, since the first run on the 

 spawning grounds consists of males. These males are often so reduced 

 in number by uncontrolled fishing that later on it is not possible to 

 secure enough milt to fertilize the eggs that are collected. Let us 

 assume, however, that half of these Alpena fish were females. Then 

 there should have been produced by this boat, in one day, 2,500 X 

 10,000 (the average number of eggs estimated by fish-culturists to be 

 produced by each pound of fish), or 25,000,000 eggs. The produc- 

 tion of whitefish on the spawning grounds at Alpena in that year was 

 over 50,000 pounds, or a potential 250,000,000 eggs, and the "north 

 ground" off Alpena is only one of the many places in Lake Huron 

 where whitefish spawn. On Lake Huron alone, then, the production 

 of whitefish e^gs might have far exceeded the entire collections by 

 all the hatcheries on hoth sides of the boundary. It is not necessary 

 to state that no such quantity of eggs was collected on Lake Huron. 



