616 U. S. BXTEEAU OF FISHERIES 



been done. However, there have come to my attention too many 

 instances of careless distribution, when fry were dumped at random 

 into waters of any depth or even into polluted rivers. Since the 

 hatcheries frequently are forced to rely for distribution of their 

 products on the charity of well-intentioned but often incompetent 

 people, perhaps better results can not be expected, but the damage 

 done by such an irresponsible procedure can not be mended nor can 

 the practice be condoned by any excuse, however valid. 



It is also a singular fact that many people who have distributed fry 

 never knew, or had forgotten, that a sudden change of temperature 

 is fatal even to an adult fish, and therefore made no provision for 

 acclimatizing the fry to their new surroundings. In the case of white- 

 fish and trout the water in the lakes at the time of planting is probably 

 nearly at zero, and if the fry were iced in the cans they would be sub- 

 jected to no great change in temperature, but when plants are made 

 at other times abrupt changes oi temperature should be most care- 

 fully guarded against. 



A further consideration, which has been neglected, concerns the 



E roper time for making plants. It is not practicable to feed the fry, 

 ut they can be retained without food without heavy mortality for 

 some time after hatching, though it is not known what the consequences 

 of such retention are. In some young animals feeding instincts 

 atrophy if they are not exercised within a certain period, and it is not 

 inconceivable that the withholding of food from fish fry for even a 

 day at the critical time may be fatal. 



To recapitulate, the practice of propagating whitefish or other 

 Great Lakes species is not in itself condemned, but an effort has 

 been made to show that the present system of permitting fishing 

 during the spawning season is vastly wasteful. No one may safely 

 affirm that the relatively few eggs that are artificially hatched — 

 few in comparison with the numbers destroyed in the effort to col- 

 lect them — can compensate for the benefits that might be derived 

 if all the fish were allowed to spawn naturally. Particular force is 

 lent to this argument by the fact that we now know absolutely noth- 

 ing about the percentage of eggs hatched under natural conditions 

 and nothing about the proper attention fry should receive after they 

 have been hatched. It follows, then, that nature should not be inter- 

 fered with blindly, lest more harm than good be done, a maxim the 

 soundness of which, as applied to certain species, fish-culturists have 

 already subscribed to. The closed season during spawning time 

 should be restored at once, and studies into the effectiveness of propa- 

 gation should be begun without delay. The collection of such sjjawn 

 as is thereafter deemed necessary should be under the supervision 

 of State and Federal authorities. 



RECOMMENDATIONS 



1. The needs of the Great Lakes fisheries should be studied, and 

 in the light of the knowledge gained regulations having for their 

 object the conserving of the fisheries should be created. We already 

 have data to show that no single law can be devised to meet the 

 varying conditions presented by one lake, to say nothing of applying 

 one law to several of the lakes. The application of any laws found 

 advisable must be independent of political boundaries. The present 



