EFFECTS OF SOUND WAVES 

 ON YOUNG SALMON 



INTRODUCTION 



The valuable salmon runs In the Columbia 

 River system face a serious reduction in size 

 due to the construction of dams. While the 

 effects of a series of dams are not yet known, 

 Schoeneman and Junge (1954) determined that 

 survival rates of two Elwha River dams 

 varied between 63 and 100 percent. Hamilton 

 and Andrew (1954) estimated survival rates 

 at Baker Dam at between 36.5 and 71.7 per- 

 cent. A single dam may not cause a critical 

 reduction in numbers of fish, but a series of 

 dams, each taking its toll, most certainly 

 would have catastrophic effects on salmon 

 populations. 



The serious problem brought about by the 

 construction of dams is twofold: (1) It requires 

 planning for the safe passage of adult fish 

 moving upstream to the spawning grounds, 

 and (2) it makes it necessary to guide or 

 force the young fish which are making their 

 way downstream, into safe passages around 

 the dams. If fish ladders prove unsatisfactory 

 for the very high dams, it may be economical- 

 ly feasible (considering the value of the salmon 

 runs) to collect and transport the adults around 

 the dams by mechanical means. The down- 

 stream movement of the young fish presents an 

 entirely different problem . 



In the waters above Bonneville Dam on the 

 lower Columbia River, Burner (1949) V found 

 that young salmon moving downstream are 

 distributed throughout the water mass. Because 

 of this random distribution, only a limited 

 number of young fish enter the bypass channels 

 provided for them . Large numbers are caught 

 in the powerful currents of water passing 

 through the hydroelectric plant and over the 

 spillway during periods of high water . 



Collins (1954) has reviewed this 

 problem and has outlined the coordinated 

 program of the several fisheries agencies 

 directed toward developing a means of 

 safely passing fish around the dangerous 

 areas. One approach to this problem 

 is the use of physical stimuli to lead, 

 direct, or force the fish into safe pas- 

 sages . The use of sound waves as a 

 possible stimulus held promise and re- 

 sulted in this investigation. 



LITERATURE SURVEY 



A search of the literature, which 

 will be published separately as an annotated 

 bibliography, revealed that little work has 

 been done with the use of sound as a lead- 

 ing or guiding force, but that there has 

 been a considerable amount of investiga- 

 tion on the conditioning of fishes to respond 

 to various sound stimuli. It has been de- 

 termined that some fish are capable of 

 perceiving sound and that some species 

 produce sound in their normal life . It is 

 therefore reasonable to assume that fish 

 might show a positive or negative audio- 

 tropism. 



Before this investigation, no con- 

 clusive research had been undertaken to 

 determine whether fish could be attracted 

 or repelled by sound waves. In fact, no 

 research, except that of Burner and Moore 

 (1953) and Brett and others (1954), had 

 been directed toward this end. The most 

 promising field appeared to be in the low- 

 frequency range of audible sound, and 

 possibly in the subaudible sound range, 

 because other investigators were able to 

 condition fish to react to sounds in these 

 frequency ranges. Supersonic andultra- 



J^/Burner, C. J., (1949). Vertical distribution of downstream migrating Chinook salmon 

 fingerlings in the Bonneville Forebay, with a note upon the rate of migration. Mimeo. Rapt. 

 U. S. Fish and Wildlife Service, Seattle, Wash., 11pp. 



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