spawning. Immediately after a tag was at- 

 tached the fish was gently released and its 

 behavior observed. For experimental purposes 

 only, each sonic tag was brightly colored so 

 that it could be easily identified. 



Forty fish were tagged in groups of ten 

 over a period of four weeks and their move- 

 ments observed. The movement of each fish 

 was carefully noted immediately following its 

 release and at one -half hour intervals for the 

 remainder of the first day. Thereafter, the 

 tagged fish were visually located in the pond 

 and their movements observed each day for 

 two weeks . 



After being released, their movements 

 were fast and erratic for the first two to five 

 seconds. Following this interval the move- 

 ments of the tagged fish appeared normal in 

 relation to the movements of the untagged fish. 

 There was no evidence of untagged fish avoid- 

 ing the tagged fish within the holding pond. 

 The tagged fish swam about freely and did not 

 appear to prefer any specific area of the pond. 



movements of a fish through a fishway can 

 be made and areas where delays occur 

 discovered. By tracking adult salmon as 

 they make their exit from a fishway, the 

 relationship of their movements to spill- 

 ways and powerhouse sections of a dam 

 can be obtained. Any changes in behavior 

 after passing through a fishway can also 

 be determined. 



The equipment also provides a method 

 for studying the movements of adult salmon 

 in a marine environment in relation to 

 climatic conditions, shore lines, ocean 

 currents, etc., as well as their movements 

 as they progress through an estuarial en- 

 vironment during their migration from salt 

 to fresh water . 



In fresh water lakes, the equipment 

 may enable biologists to determine adult 

 fish behavior in relation to ecological con- 

 ditions, and information on their orienta- 

 tion in the selection of a particular stream 

 for spawning purposes. 



In addition to determining the effect of the 

 sonic tag on the natural movements of an adult 

 salmon, these experiments showed that the 

 "hog-ring" type attachment was successful in 

 securing the tag to a fish. During the ex- 

 periments, the holding pond was completely 

 seined two or three times each week to remove 

 the fish ready for spawning. Although the 

 tagged fish received rough handling during 

 these seining operations, the sonic tags re- 

 mained securely attached for at least two 

 weeks, after which they were removed. 



Although the sonic equipment was de- 

 veloped to provide specific data on adult 

 salmon movements relative to dams, it 

 can be used to supply information on the 

 movements of a large variety of adult fish 

 and aquatic animals under natural condi- 

 tions. As it is employed, additional uses 

 will become apparent and it will become 

 increasingly valuable as fishery research 

 equipment . 



SUMMARY 



USES OF SONIC EQUIPMENT 



The sonic equipment can be used under a 

 variety of natural conditions to study the be- 

 havior of adult fish . In the vicinity of dams, 

 the manner in which an adult salmon locates a 

 fishway entrance or collection system opening 

 and chooses an entrance or opening can be 

 determined. Measurement of the rates of 



1 . New sonic equipment has been de- 

 veloped for tracking individual adult salmon 

 and observing their movements under natur- 

 al coaditions, in relation to Columbia River 



2 . A sonic tag is attached to an adult 

 salmon migrant and its movements are 

 observed with calibrated receiving equipment 



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