30 U. S. BUREAU OF FISHERIES. 



One of the greatest needs in connection with Pacific salmon propa- 

 gation is more adequate protection for the fisheries through the 

 enactment and rigid enforcement of restrictive legislation. The 

 regulations should provide (1) for the return to the waters unin- 

 jured of all immature fish that may be taken in nets or other fishing 

 devices; (2) for a weekly closed season, thus assuring ascent to the 

 natural spawning grounds of a certain proportion of the unripe 

 fish; (3) for cessation of fishing operations after the canneries have 

 put up a fixed number of cases, the limit of the pack to be deter- 

 mined by investigations in each locality, which must be such as will 

 permit the escapement of a sufficient number of fish to insure con- 

 tinuation of the run in each locality; (4) for systematic destruc- 

 tion of Dolly Varden trout in salmon streams, these fish having been 

 found to be among the greatest enemies of young salmon; (5) for 

 setting aside natural lakes for use as salmon-rearing reservoirs; (6) 

 for seeding of eyed salmon eggs in the more inaccessible lakes, in 

 order that the young may pass the early stages of their existence 

 in waters which are comparatively free from natural enemies. Dur- 

 ing periods of flood the fish in these lakes would pass from them over 

 slight falls and through the intervening rapids, entailing little loss. 

 In certain barren lakes the application of such a plan would necessi- 

 tate the provision of a food supply. Work of this character has 

 already been undertaken in a limited way in the vicinity of the 

 Yes Bay (Alaska) station. 



The tray system recently introduced in connection with the propa- 

 gation of salmon at the western stations is proving a very important 

 factor in the work. The eggs are carried in the regular baskets 

 until Avithin two or three weeks of the hatching period, when they 

 are transferred to 14 by 16 inch trays, made of 1 by 1^ inch lumber 

 and covered M'ith wire cloth 14 to 16 meshes to the inch. From 

 3.500 to 4,000 sockeye-salmon eggs are placed on one of these trays. 

 The trays are stacked from 6 to 8 deep in a trough compartment, 

 thus increasing the holding capacity of a 16-foot trough from six 

 to eight times and permitting the safe development of 300,000 to 

 400,000 fry in a space which was formerly required for 50,000. The 

 fry are carried in dark, deep pockets, with the view of providing, 

 so far as possible, the seclusion afforded in natural hatching, as it is 

 believed they will develop under such conditions all the character- 

 istics of gravel-hatched fry. 



Another favorable feature is the more compact arrangement of the 

 hatching apparatus, which permits of a much better control of the 

 fry than under the basket and open-trough system. While it is 

 entirely practicable to spread the green eggs on the trays directly 

 and continue using them throughout the incubation period and up 

 to the time the fry are ready to be fed, it has been found more satis- 

 factory to carry the eggs in the baskets to the point of hatching and 

 then transfer them to the trays, as such an arrangement permits of 

 a thorough cleaning of all apparatus involved. Writing in regard 

 to the use of this system, C. H. Van Atta, superintendent of the Yes 

 Bay (Alaska) station, states : 



Sixty thousand sockeye-salmon fry were placed on 12 trays, each 13^ by 

 25 inches in dimensions. The trays were stacked in one regular basket com- 



