SONIC EQUIPMENT FOR TRACKING INDIVIDUAL 



FISH 



The U. S. Fish and Wildlife Service is de- 

 veloping underwater sonic equipment for 

 obtaining a detailed knowledge of the move- 

 ments of individual adult salmon in relation 

 to Columbia River dams. Each dam on the 

 Columbia River presents a chance for delay 

 in migration with injurious consequences if 

 the delay is prolonged. Since new dams are 

 under construction and in the planning stages, 

 information on salmon behavior in relation 

 to dams is needed for the effective operation 

 of present fish passage facilities and for the 

 design and location of new facilities. Data on 

 adult salmon behavior at dams is scarce be- 

 cause the methods available for obtaining the 

 information have been confined to visual ob- 

 servations which are limited by the turbidity 

 of the water and by hydraulic conditions, and 

 to tagging operations which supply information 

 on the average rates of movement, but no in- 

 formation on the movements of a tagged fish 

 between the point of release and the point of 

 recapture. Use of sonic equipment may over- 

 come these limitations so that the complete 

 movements of individual fish can be tracked 

 under natural conditions in daylight or dark - 

 ness. 



The development of the equipment was 

 initiated by Dr . Gerald Collins, U. S. Fish 

 and Wildlife Service and it was designed and 

 manufactured under contract by the Minneapo- 

 lis-Honeywell Regulator Company, Seattle 

 Development Laboratory. While the final 

 device has not been completed a practical 

 working model has been produced and is be- 

 ing used to observe fish movements under 

 natural conditions . 



Considerable interest has been shown by 

 fishery research biologists in this equipment 

 because it provides a new research tool for 

 studying the behavior of fish and aquatic 



animals in their natural environment. 

 Since modifications are anticipated to 

 increase the efficiency and accuracy of 

 the present model, this report is a gen- 

 eralized description of the equipment 

 and its potentialities . When the modifica- 

 tions have been completed and the 

 equipment is in the final stage of develop- 

 ment, a more detailed technical report 

 will be published. 



SONIC EQUIPMENT 



The equipment now being developed 

 to track individual fish includes a self- 

 contained miniature underwater sonic 

 transducer or sonic tag and receiving 

 equipment. The sonic tag is attached to 

 a fish (Fig. 1) and the transmitted sound 

 waves are picked up by the receiving 

 equipment. Since the receiver is cali- 

 brated in bearing, distance and angle in 

 relation to the sonic tag, the position of 

 the fish can be pin-pointed when desired, 

 and detailed movements of individual fish 

 can be easily plotted. 



Miniature Underwater Sonic Transducer 

 (Sonic Tag) 



The transducer is essentially an 

 aluminum capsule 2-3/8 inches long and 

 .86 inches in diameter, weighing approx- 

 imately 2 grams when immersed in water. 

 All of the component parts are contained 

 within the capsule The 15 -volt battery 

 power -source and me electronic circuitry, 

 imbedded in styrene plastic foam, are 

 located between the two ends of the capsule . 

 The transistor is solidly attached in one 

 end of the capsule; the resonating crystal 

 is cemented in the opposite end. The latest 

 sonic tag is shown in Fig. 2 in relation to 

 two earlier experimental models . 



