2 U. S. BUREAU OF FISHERIES 
of spawning fish en route to their native streams. The development 
of a commercial fishery in the offshore waters of Bristol Bay could 
only result in the disruption of the industry ashore, which takes its 
supply from coastal waters under strict regulation of the Federal 
Government, for adequate escapement of fish to the spawning grounds 
must be assured if the resource is to be maintained. The threat of 
developing an offshore fishery, therefore, was the occasion, if not the 
primary cause, of the undertaking of a comprehensive investigation 
of the Bristol Bay salmon, for the fundamental objective in such a 
study is to acquire sufficient knowledge of the natural history and 
the requirements of these fish and the factors that favor or hinder 
survival of each year’s brood to permit a more certain and a more 
flexible control of the commercial fishery in the interest of wise 
management. 
The investigation has been divided into two major phases—a study 
of the life of the salmon in fresh water, including the varying success 
of annual propagation and the factors that affect it and the natural 
requirements, habits, migrations, feeding conditions, and survival of 
the salmon during their life in the sea. 
With the aid of the United States Coast Guard cutter Redwing, a 
program of hydrographic investigations in the offshore waters of 
Bristol Bay was undertaken to study the oceanic conditions that so 
profoundly affect the well-being of the salmon schools. During 1939 
this program will be expanded to include ‘experimental fishing to 
study the schooling of fish, their routes and times of migration, their 
relative mortality, and the probable effects of the commercial fishery 
upon the supply. Likewise, a more intensive study of the stream life | 
of the salmon will be undertaken to determine the success or failure 
ot spawning and the responsible factors, in the hope of perfecting a 
system of prediction of future yields that will simplify the economic 
exploitation of the fishery and facilitate governmental regulation. 
A special fund of $20,000, provided by the appropriation act for 
the fiscal year ending June 30, 1939, permitted the establishment of 
another new project of considerable importance. This fund is for the 
construction, operation, and maintenance of fish screens and ladders 
on Federal irrigation projects and the conduct of necessary investiga- 
tions and surveys,. preparation of designs, and supervision of con- 
struction. It also, for the first time, permits the Bureau to discharge 
its obligation to determine the requirements for fishways or other fish- 
protective devices which, under the terms of the Federal Water 
Power Act of 1924, the Secretary of Commerce is authorized to pre- 
scribe at dams constructed under licenses issued by the Federal Power 
Commission. 
With this authority a Hydraulics Section was established, under 
the supervision of the Division of Scientific Inquiry, employing a 
competent biologist for the study of fishway requirements and an 
experienced engineer for the design of the fish-protection facilities. 
During the latter part of the year the engineer who was first em- 
ployed not only assisted in the design of fish screens constructed with 
emergency funds in the Pacific Northwest States, but also redesigned 
a sereen in the Pishkun Reservoir, Montana, which had proved inef- 
