REPORT OF THE COMMISSIONER OF FISHERIES. 31 



species reiDresents conservation of the highest type, since the eggs 

 would be sent to the market in the fish and lost were it not for the 

 bureau's intervention. In past 3^ears the fishermen of the region 

 have appeared reluctant to cooperate with the bureau in furnishing 

 eggs, but they now seem to realize the importance of the work and 

 it is believed there will be no difficulty hereafter in obtaining an 

 egg supply. 



The Weldon substation, on the Roanoke River, was fitted up for 

 striped-bass propagation as usual, but egg collections were discon- 

 tinued at the height of the sx^awning season, as it was found that the 

 large amount of trade waste discharged into the river from a local 

 manufacturing plant was polluting the water and killing the fry 

 liberated from the hatchery. The total egg collection amounted to 

 22,08-i,000. At the })eginning of the spawning season the fishermen 

 at this point were loath to cooperate in the collection of eggs on a 

 fair basis, but this opposition was overcome after the situation had 

 been fully explained to them. 



The usual collection of adult Atlantic salmon at the Craig Brook 

 (Me.) station could not be made, due to the washing away of the 

 barrier at the Dead Brook inclosure, where it has been customary to 

 hold the fish for several months awaiting the development of their 

 spawn. Five hundred thousand Atlantic salmon eggs, received at 

 the Craig Brook station from the Canadian Government in exchange 

 for an equal number of trout eggs, produced 466,000 fry, all of which, 

 with the exception of a small number reserved for rearing to the 

 fingerling stage, were liberated in the Penobscot River and its trib- 

 utaries. 



It is believed that greater results than heretofore may be attained 

 by rearing a comparatively small number of fish to the No. 2 or No. 

 3 fingerling stage before liberating, and this policy will be pursued 

 in connection with any future operations with this species. It is 

 probable, however, that Atlantic salmon propagation on the Penob- 

 scot will be entirely discontinued unless the fishermen of the region 

 show a gi'eater willingness than they have thus far shown to coop- 

 erate in the work. 



PROPAGATION OF COMMERCIAL SPECIES OF THE GREAT LAKES. 



The bureau's work in this region was concerned as usual with the 

 propagation of such important commercial fishes as the lake trout, 

 whitefish, pike perch, yellow perch, and carp. Most of the eggs ob- 

 tained from these species are taken from fish caught for the market 

 by the commercial fishermen and incubated in the bureau's hatcheries, 

 the resulting fry being liberated on the natural spawning grounds. 

 Owing to hea\^^ storms, which prevailed practically throughout the 

 incubation period, there was a considerable shortage in whitefish 

 egg collections as compared with the previous year, and the quality 

 of those secured was impaired by the quantities of slime and sedi- 

 ment carried in the water supply. On the other hand, the weather 

 in the spawning fields where lake trout eggs are obtained was favor- 

 able, and the collections of that species exceeded those made in 1922. 



In the eastern end of Lake Ontario the ciscoes, for some unknoAvn 

 reason, did not resort to the spawning grounds in the usual numbers. 

 Especially was this true in the ordinarily prolific Bay of Quinte, the 



