MICHIGAN (Cont. ) 



power in which an electrical field in the water is substituted for the screens or 

 "racks" of a conventional fish weir and trap. 



Lakes Huron, Superior, and Michigan; hdqrs. Hammond Bay Fishery Lab. , 

 Rogers City; began 1951, continuing; Leo F. Erkkila, Leader. 



Address inquiries to: James W. Moffett, Chief, 1220 East Washington 

 Street, Great Lakes Fishery Investigation, Ann Arbor, Mich. 



2. Development of Fish "Leading" or "Assembling" Devices. 



The objective is to develop a device utilizing sonne form of pulsed direct 

 current which may be used as an accessory to the electro-mechanical weir and 

 trap to aid in the rapid transfer upstream of food and game fishes migrating 

 with the sea lampreys. 



Lakes Huron, Superior, and Michigan; hdqrs. Hammond Bay Fishery 

 Laboratory, Rogers City; began 1951, continuing; Alberton L. McLain and 

 Bernard Smith, Leaders. 



Address inquiries to: James W. Moffett, as in No. 1 above. 



3. Survey of Great Lakes Tributary Streams. 



The objectives are to determine the location of all streams in the Superior, 

 Michigan and Huron basins in which successful reproduction of the sea lamprey 

 can occur, and to determine the degree to which such streams are or may be 

 utilized by the species, to determine therefrom where control structures must 

 be located. 



Hdqrs. Hammond Bay Fishery Lab., Rogers City; began 1950, to close, 

 1954; Leo F. Erkkila, Leader. 



Address inquiries to: James W. Moffett, as in No. 1 above. 



4. Chemical Control Techniques. 



The objectives are to determine whether a specific toxicant exists which 

 will be lethal to larval lampreys but harmless to other aquatic life occupying 

 the same environment and to determine whether this toxicant can be applied in 

 streams in an efficient and economical manner. 



Lake Michigan; hdqrs. Hammond Bay Fishery Lab. , Rogers City; began 

 1950, continuing; Vernon Applegate, Leader. 



Address inquiries to: James W. Moffett, as in No. 1 above. 



5. Scale Structure of Lake Trout. 



The objectives are to determine the validity of the annulus as a year -mark 

 and to derive a body-scale regression curve for use in the calcuation of growth. 



All available sources; hdqrs. Ann Arbor; began January 1950, to close 

 December 1954; Louella E. Cable, Leader. 



Address inquiries to: James W. Moffett, as in No. 1 above. 



6. Abundance of Small Trout in Lake Michigan and Lake Superior. 



The objective is to follow annual, seasonal, and local fluctuations in the abun 

 dance of snnall lake trout as reflected in numbers taken in chub gill nets as a 

 means of measuring trends in the stocks and later of judging the results of 

 attempts at rehabilitation. 



Hdqrs. Ann Arbor; began May 1950, to close January 1954; Paul H. Esch- 

 meyer, Leader. 



Address inquiries to: James W. Moffett, as in No. 1 above. 



7. Movements of Lake Trout in Lake Superior. 



Through the tagging of both legal-sized and under-sized lake trout in differ- 

 ent regions of Lake Superior to determine the extent of migrations with special 



54 



