PROGRESS IN BIOLOGICAL INQUIRIES, 1934 369 



inir the period of construction are beiiif; considered as rapidl}' as 

 possible. 



The fishways for upstream nii<:iini(s recdniniended by the Bureau 

 of Fislieries include 3 fish ladders, 5 fish locks, and 15 units of a new 

 feature known as a " collect in<>; system." The fish ladders are of 

 special design to adapt them for wide ranges of variation in tailrace 

 and forebay fluctuation. The fish lock, which is new in ai)plication 

 to salmon and trout, embodies the essential principles of a naviga- 

 tion lock with minor diiferences to adapt it to the special use. The 

 collecting system consists of a series of entrance weirs distributed at 

 various points along the obstruction, all entrances communicating 

 with a common passage which leads to the base of the fishway proper. 

 The quantity of water flowing through the common passage is aug- 

 mented by an auxiliary water supply, thus presenting as an attraction 

 to the fish a much larger quantity of water than can be supplied by 

 the fishway proper. The collection systems are rcconunended for use 

 both with the fish locks and tlie fish ladders. 



GREAT LAKES FISHERY INVESTIGATIONS 



Owing to the continued curtailment of the Budget, no field work 

 was conducted on the (ircat Lakes during the calendar year 1934, 

 The Great Lakes research conducted under Dr. John Van Oosten 

 was confined entirely to work in the laboratories furnished by the 

 University of Michigan at Ann Arbor. 



As in past years, the Bureau continued its cordial relations with 

 the various Great Lakes States and provided them, whenever possible, 

 with information and advice concerning th.cir respective fisheries. 

 Dr. Van Oosten represented the Bureau at various fisheries confer- 

 ences on the Great Lakes as well as at the public hearing called by 

 the National Recovery Administration at Muskegon, Mich., on April 

 25 to discuss the proposed Great Lakes fisheries code. 



Much progress has also been made in what is often considered the 

 more scientific aspect of fisheries research. The analysis of fisheries 

 statistics begun on Lake Huron has been extended to Lake Michigan 

 and Lake Erie, Life history studies of the whitefish, cisco, perch, 

 yellow and blue pike-perch, and sauger of Lake Erie are nearing 

 completion. It is planned to extend these important investigations 

 to the other lakes of the Great Lakes chain. 



FISHERY STATISTICS 



The intensive statistical study of the commercial fisheries of the 

 Great Lakes waters of the State of Michigan begun in 1933 was con- 

 tinued through 1934, Complete and detailed data are now available 

 for the Lake Huron fisheries over the 5-year period, 1929-33. Simi- 

 lar statistical analyses have been started for the commercial fisheries 

 of the Michigan waters of Lake Erie and Lalce Michigan. In a brief 

 preliminary publication, Dr. Ralph Hile and William R. Duden de- 

 scribed the methods employed in these statistical investigations. 



The statistical data on the commercial fisheries of Lake Huron 

 have proved particularly valuable in their apjdication to the prob- 

 lems relative to the use of the deep trap net for the capture of white- 



