that picks up the sound waves from the 

 tag. 



3 . The sonic fish tag is attached to 

 the fish with a nickel -chromium hog-ring 

 using special pliers. 



4. The tag is attached underwater with- 

 out handling the fish. 



5 . There is no apparent effect of the 

 sonic tag on the natural movements of the 

 fish. 



6. The sonic equipment can be used in 

 fresh or salt water to track the movements 

 of individual fish and other kinds of aquatic 

 animals . 



ACKNOWLEDGMENTS 



The technical development and produc- 

 tion of the sonic equipment was accom- 

 plished under the supervisioB of Roy Malm 

 of Minneapolis -Honeywell Regulator Com- 

 pany while John Dudley was responsible 

 for the design and operation of the equip- 

 ment. 



Thanks are due Charles Ellis, Super- 

 visor of Hatcheries for the State of 

 Washington, for making available adult 

 salmon and an experimental area for testing 

 the effect of the sonic tag on natural be - 

 havior. The cooperation ancLas si stance of 

 the personnel of the Washington State Fish 

 Hatchery at Auburn is also gratefully 

 acknowledged. 



Appreciation is also expressed to 

 Fishery Research Biologist James H. 

 Johnson for assistance in testing the equip- 

 ment and photographing the equipment. 



REFERENCES 



Minneapolis -Honeywell Regulator Company 



1954 



1955 



Sea Scanar Operators Manual 

 Prepared by Marine Equip. Div. 



Seattle, Washington. 



Operating instructions for the Hydrophone Receiver (38A1), 



listening hydrophone (39A1), and pinger sound source (35B1), 



Seattle, Washington. 



Prepared by Seattle Development Laboratory, 



Seattle, Washington. 



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