30 American Fisheries Society 



Of course we are not claiming that the 270 millions of fry 

 produced each year at the U. S. station at Put-in Bay, or the 

 millions produced at the other stations means a production of 

 that number of adult fish each year. Neither can we give even an 

 approximate estimate of the number that reach maturity in the 

 Great Lakes, but judging by the percentage known to have reached 

 the age of reproduction after having been liberated at the fmgerling 

 stage, we think that it is safe to estimate that at least ten per cent, 

 of all the fry liberated would reach maturity if not destroyed by 

 other than natural causes. If so, then there were produced each 

 year from this station alone 27 millions of fish and averaging 

 them at two pounds each, we have a production of 2,700 tons a 

 year. As the kinds of fish propagated are of the best varieties 

 and sell for the highest prices in the market — perhaps an average 

 price of 12>^ cents a pound to the consumer would be a fair esti- 

 mate — this would give us a production of $675,000 worth of fish 

 each year. To digress a little from the subject, I will say that the 

 total cost of this production, including salaries, pay for eggs, 

 temporary labor, both in the field and at the station, the upkeep 

 of the station, together with the maintenance and the entire cost 

 of operating the Steamer Shearwater, which is used in collecting 

 the eggs and distributing the fry, has averaged less than fifteen 

 thousand dollars a year. This leaves a clear profit of $660,000.00 

 a year. So much for the production, now we will endeavor to 

 consider the destruction and some of the conditions which 

 cause it. 



The natural destruction begins with the loss of the fertilized 

 eggs deposited by the parent fish on the spawning grounds, which 

 are eaten by the ground-feeding fishes, such as suckers, mullets, 

 redhorse, and in fact by all the aquatic life that feeds on the lake 

 bottom; also those eggs which become covered with mud and 

 silt and are smothered; the young fish eaten by the minnows 

 during the early fry stage, and the fingerlings eaten by the larger 

 fish. This loss can not be estimated, neither can it be controlled 

 to any extent, but the greatest source of destruction, and one that 

 can be controlled, is that which is carried on by mankind. This 

 destruction should be divided into two classes, the economical 

 and legitimate, and the unnecessary, wanton and criminal. By 



