BUREAU OF FISHERIES 97 



Great Lakes -fisheries. — Owing to the continued curtailment of the 

 bud*2:et, no field work was conducted on the Great Lakes durinn: the 

 past year. The staff, however, has been en^a<>ed in analyzini^ ma- 

 terial gained in previous j'ears' observations and in assisting in 

 legislative matters with the States. 



The most urgent need in this region today is concerned with uni- 

 form regulations of commercial fishing. Many attempts in the past 

 have failed to secure coordinated legislation among the States, but 

 progress in improving conservation laws has resulted from many 

 conferences during the past yaav. 



An intensive statistical study of the commercial fisheries in Great 

 Lakes waters of the State of Michigan has been continued. These 

 studies, based on detailed records secured by the State Conservation 

 Department, demonstrate the rapid depletion of whitefish supply 

 by deep trap nets, and the statistical evidence of their destructive 

 action was directly instrumental in securing legislation regulating 

 and restricting the use of this gear. 



A study of the life history of the important commercial species 

 of the pike perches is nearing completion, and similar studies of the 

 yellow perch were pursued. 



PadfiG coast -fishery investigations. — One of the most important 

 undertakings of the Division of Scientific Inquiry is a comprehensive 

 program of investigation of the salmon fisheries of the Columbia 

 River, begun in July 1934. The aims of this investigation are : 



1. To provide for rational regulation of a commercial fishery in 

 the lower Columbia in order to permit an adequate escapment of 

 fish for spawning purposes. 



2. To assure free passage of spawning migrations over the various 

 dams in the Columbia River. 



3. To provide for increased spawning in the upper tributaries 

 by removing all unnecessary obstructions and by rehabilitating 

 spawning grounds formerly productive. 



4. To improve artificial propagation of salmon and to increase 

 production by reestablishing runs in suitable tributaries. 



5. To improve survival by reducing the pollution hazards. 



6. To prevent loss of downstream migrants in unscreened irriga- 

 tion divereions. 



A complete survey of the river system has been undertaken in 

 order to assess these various problems, including a detailed analysis 

 of the commercial catch from earliest times to the present. Detailed 

 recommendations were offered by the Bureau to the War Depart- 

 ment for the construction of fish protective works at Bonneville 

 Dam including four gravity fish ladders of an improved type and 

 three fish locks or hydraulic lifts for conveying spawning Ash over 

 the dam, and a series of fingerling bypasses to protect downstream 

 migrants; $3,200,000 has been allotted for this construction and al- 

 though the problems of fish protection are by no means solved, the 

 Bureau is confident tliat effective protection of the Columbia River 

 salmon runs at this point will be afforded. 



With an allotment from the Public Works Administration, the 

 Bureau has constructed screens for three important diversions on 

 the Yakima River for the protection of young salmon from loss in 

 irrigation canals of the Reclamation Service. Two additional screens 

 were constructed on other waters] h ds for a 3imilar purpose. 



