ARTIFICIAL. PROPAGATION OF WHITEFISH, ETC. 21 



trout during each season. Inasmuch as the habits of the lake trout 

 take it to deep water immediately after spawning, whereas the young 

 whitefish remain in shallows, the few whitefish that are destroyed 

 in this manner are either stragglers from shoal to deep water or are 

 taken by trout aimlessly wandering from their natural range. The 

 lake trout is an omnivorous feeder and has a ravenous appetite. It 

 greedily devours all fishes possessing fins of flexible character; and 

 jackknives, corncobs, and other articles equally indigestible have 

 been found in its stomach. 



ENEMIES. 



The spawn and fry of lake trout suffer from the same enemies as 

 the young of all fishes, but the mature fish are too formidable for 

 other species to prey upon. They are troubled with a few parasites. 

 Occasionally individuals very thin in flesh and sickly looking, 

 known to fishermen as " racers," are found swimming near the sur- 

 face. No sufficient cause has been discovered for this condition, as 

 the racers are no more afflicted with parasites than are healthy fish. 



COMMERCIAL VALUE AND ABUNDANCE. 



In the early history of the fisheries of the Great Lakes the lake 

 trout was so plentiful that it did not command a price commensu- 

 rate with its edible qualities. It has since increased in favor and is 

 to-day one of the highly prized and, with the exception of the white- 

 fishes and ciscoes, perhaps the most numerous food fish of the Great 

 Lakes. It is exceeded in weight by the sturgeon only. Instances are 

 cited by fishermen and others of lake trout weighing as high as 125 

 pounds, and its average weight has been given at from 20 to 30 

 pounds; but of late examples are rarely found exceeding 10 or 15 

 pounds. If unmolested by man they might again reach the enormous 

 weight of early citations, their sluggish movements and voracity be- 

 ing conducive to such a result. 



In 1917 the catch of lake trout from the five Great Lakes and 

 Lake St. Clair amounted to 13,344,130 pounds, valued at $1,286,704, 

 the catch being exceeded in weight and value only by that of the 

 ciscoes. Very little thought was given to the conservation of the 

 lake trout until 1886, when it became apparent to those interested 

 that decisive steps must be taken to provide against the extermina- 

 tion of a most valuable food fish. Artificial propagation was un- 

 dertaken at this time and has been continued by the Federal Govern- 

 ment and the several States interested. During the fiscal year 1921 

 the output of lake trout fry and fingerlings from the hatcheries 

 operated by the Bureau of Fisheries amounted to 19,478,500. 



Attention was also directed to the desirability of regulating the 

 methods employed in the fishery, and all States have enacted laws 

 specifying the forms of apparatus that may be used and the season 

 of the year when fishing may be legally conducted. Unfortunately 

 such laws are not uniform in their application. However, most of 

 the States require all fishermen to deliver, either to agents of the 

 bureau or the State, all ripe eggs taken in their work or to afford 

 suitable accommodations to spawn takers employed by the bureau 

 or State. 



