30 Tz^'eitty-sc7'ciifJi Aiuuial Meeting 



a hatching percentage as is secured from domesticated fish in 

 ponds. At least, that has been our experience on this river. And 

 yet, the Au Sable River is probably one of the best-adapte.! 

 streams for a work of this kmd in the United States: the only 

 drawback, if any, is the small size of the fish. 



From the experience and observaticjn. of all practical fisli- 

 culturists, it ha,s been concluded that not more than 5 per cent; 

 of brook-trout eggs are hatched in a state of nature. Our observ- 

 ations on the Au Sable River have verified this. It is impossible 

 for a large percentage of eggs to be impregnated in the rapid 

 water of that stream. Impregnation is not only more difficult 

 for this reason, but the rapid action of the water, in addition 

 to that of the fish, often covers many of the eggs with gravel to 

 such an extent that they are smothered ; while large quantities 

 of those not thus destroyed are subsequently eaten by the fish. 

 In our work we took from 400,000 to 500,000 eggs. If these 

 had been left in their natural element not more than 25,000, or 

 at most 40,000, would have hatched, whereas by artificial im- 

 pregnation and culture, at least 70 per cent, were preserved, re- 

 sulting in from 280,000 to 350,000 fry. Of these, t 00,000 were 

 planted back in the Au Sable River and its branches this season. 

 From this it will be seen that it is not only practicable and of 

 great advantage to take the egg^ from the wild fish, hatch and 

 plant them again, but that the very stream from which they were 

 taken this season is better stocked, to the extent of about 60,000 

 or 70,000 fry than it would have been if the eggs had not been 

 removed, and this does not take into consideration the several 

 hundred thousands that have been planted elsewhere. Nature, 

 both in forest and stream, notwitlistanding her prodigality, is 

 sulBcient for self-maintenance, and under favorable circum- 

 stances for gradual development, but as is well known, is not 

 sufficient both for self-maintenance and the supply of man's 

 wants., A stream once stocked and left entirely undisturbed, 

 will not decrease in its number of fish, but will invariably do so 

 if there is an unusual draft upon' its resources, either during 

 the entire year or during any number of months of each year. 

 For this reason a partially-closed season is seldom, if ever, suffi- 

 cient to preserve the desired equilibrium. For this method to 

 be absolutely effectual, the closed season should extend over 

 eleven months of each year, if not the entire twelve. But in my 

 opinion it is not absolutely necessary to close the season during 

 any part of the year ; it is only necessary to save and mature the 

 incalculable resources that nature now wastes, and thereby bv 



