34 REPORTS OF THE DEPARTMENT OF COMMERCE. 



PROPAGATION OF COMMERCIAL FISHES OF GREAT LAKES. 



While there were many discouraging features connected with the 

 propagation of the commercial fishes of the Great Lakes, the aggre- 

 gate output of the hatcheries was nearly twice as large as in 1918. 

 Unfavorable weather during the spawning season, together with the 

 scarcity of skilled labor, tended to reduce the numbers of lake trout 

 and whitefish produced, but the poor showing in that branch of the 

 work was in part compensated for by the large increase in the out- 

 put of cisco and pike perch, the production of which was six times 

 greater than in the preceding year. 



For the first time in its history, the Duluth hatchery was stocked 

 with pike-perch eggs collected in State waters, this being made 

 possible through an arrangement with the State authorities for co- 

 operative work at Pike River. The Bureau's share of the operations 

 was 40,000,000 eggs. 



A temporary hatchery established at Bay City, Mich., on Saginaw 

 Bay, was equipped with apparatus from other Michigan stations 

 and supplied with water from the city mains for the purpose of 

 utilizing the large number of pike-perch eggs which were reported to 

 be obtainable from the commercial fishermen of that region. The 

 fishermen cooperated to the fullest possible extent in supplying eggs, 

 and the success of the collections far exceeded all expectations. 

 Consignments of eggs from this station were as follows: Two 

 hundred and eighty-eight million eight hundred thousand to the 

 Detroit State hatchery; 60,000,000 to the New York Conservation 

 Commission, and 29,250,000 to the auxiliary hatchery of the Bureau 

 at Charlevoix. The 95,400,000 eggs which were retained at Bay 

 City were lost owing, it is supposed, to chlorine used by the city 

 authorities for clarifying and purifying the water. It is evident that 

 favorable work in pike-perch propagation may be done at this point, 

 and the establishment of a hatchery with a capacity of at least 1,000 

 jars is desirable. This plant could handle other fish besides pike 

 perch, and there is particular need for artificial propagation ad- 

 dressed to local ciscoes or lake herrings. 



In the Lake Michigan and Lake Huron fields covered by the auxil- 

 iaries of the Northville station, it was necessary, owing to lack of men, 

 to reduce the number of egg-collecting points formerly operated, 

 which condition, combined with abnormally warm weather and a 

 small run of fish, resulted in the taking of only 33,269,000 lake-trout 

 eggs, less than half the previous year's record. Whitefish eggs for 

 the substation at Charlevoix to the number of 35,548,000 were secured 

 from Lakes Michigan and Huron and were supplemented by ship- 

 ments of 64,680,000 eggs from Lake Erie, all oi poor quality. In 

 the whitefish operations of the Put in Bay hatchery in Lake Erie, 

 420,650,000 eggs were collected, all but 50,000,000 being obtained 

 from fish taken by commercial fishermen. A considerable propor- 

 tion of these eggs were consigned to the various State fish commis- 

 sions, and upward of 126,000,000 vigorous fry were liberated from 

 the Put in Bay hatchery. 



The Cape Vincent hatchery had an unusually successful season. 

 For the first time since its establishment, no lake-trout eggs were 

 shipped from other stations, full reliance being placed on home col- 

 lections. Whitefish eggs to the number of 93,510,000 were secured 



