ATTEMPTS TO GUIDE SMALL FISH WITH 

 UNDERWATER SOUND' 



by 



Clifford J, Burner and Harvey L. Moore 

 Fishery Research Biologist 



One of the most uncertain and difficult 

 problems in providing for the safe passage 

 of migratory fish around high dams is created 

 by the migration of the young salnnon to the 

 ocean from upstream spawning grounds. Ex- 

 periments indicate that turbine and spillway 

 hazards at one dam may cause a considerable 

 loss of these small fish. This loss becomes 

 of increasing concern when multiplied by each 

 new dam under construction or proposed for 

 the Columbia River. When this potential threat 

 to the resource first became known, the Fish 

 and Wildlife Service initiated studies to develop 

 methods of providing safe downstream passage 

 for fingerlings. Basic to the accomplishment 

 of this objective is a kno'wledge of their dis- 

 tribution in the river. 



Research on this problem revealed that 

 fingerlings of chinook salmon (Oncorhynchus 

 tshawytscha) in the Columbia River are found at 

 all depths of the water and from shore to 

 shore m nearly equal numbers. Thus we 

 knew that fish were passing through turbines 

 and spillways in proportion to the amount of 

 water passing through these structures, and 

 it became urgent that we develop methods of 

 diverting the fingerlings into safe channels 

 of migration. The desirability of sound as a 

 means of guiding fish cannot be overlooked, 

 because it does not require the use of struc- 

 tural equipment such as floating booms or 

 screens and because it can be beamed and 

 reflected much like light. 



Through the cooperation of the U.S. Arnay 

 Corps of Engineers and the U.S. Navy, the 

 Fish and Wildlife Service was given the 

 opportunity to test the effects of underwater 

 sound of various frequencies and amplitude 

 on fish. The tests were made during November 

 and December 1947 and March and April 1949, 

 at the Biological Station at Leetown, West 



'Revision of Special Scientific Report--Fisheries No. Ill, dated 

 September 1953. 



Note: --Clifford J. Burner, Fishery Research Biologist, Bureau of 

 Commercial Fisheries Biological Laboratory, U.S. Fish and Wildlife 

 Service, Seattle, Washington; and Harvey L. Moore, presently For- 

 eign Trainee Officer, Bureau of Commercial Fisheries, U.S. Fish 

 and Wildlife Service, Seattle, Washington. 



Virginia. The tests were limited to four 

 undersea warfare sound producing instru- 

 ments involving three principles of sound 

 production: (1) electromagnetism, (2) Piezo- 

 electricity, and (3) the hydraulic turbine. Be- 

 cause young Pacific salmon were not available 

 at the site, the physiologically similar rainbow 

 (Salmo gairdneri) and brown (S. tratta) trouts were 

 used as experimental animals. 



CHARACTERISTICS OF SOUND AND 

 SOUND DEVICES 



All sounds are the result of physical vibra- 

 tions. Sound waves in the air are the result 

 of molecules of air being pushed against one 

 another to form compression waves. This 

 distinguishes sound waves from radio, radar, 

 or similar electronic impulses which are the 

 result of wave motion between the molecules. 

 Sound waves in the water develop when the 

 medium is alternately compressed and ex- 

 panded mechanically. In either of the two 

 elements, sound waves travel from the source 

 in a pattern similar to that obtained by drop- 

 ping a stone into a quiet pool.' 



Sound waves travel in air at a speed of 

 1,087 feet per second (f.p.s.) (0° C: 76 cm. 

 pressure) and in water at 4,890 f.p.s. varying 

 with temperature and pressure. The greater 

 elastic constant of water makes it nearly ideal 

 for the tramsmission of sound waves. The 

 same hypotheses and laws that apply to sound 

 in the air are applicable to subaqueous sound. 



Audible sound frequencies range from 16 

 to 20,000 cycles per second (c.p.s.). However, 

 the upper limit may be raised with sufficient 

 power. The term subsonic or subaudible sound 

 refers to that part of the sound range below 

 16 c.p.s. Ultra or supersonic refers to the 

 inaudible frequencies extending above 20,000 

 c.p.s.' Some generators now in use are capable 

 of producing inaudible ultrasound of 1 2,000,000 

 c.p.s. Recently this part of the sonic band has 



'Actually sound waves expand in all directions from a nondirec- 

 tional source, in a series of concentric spheroids. 



'The term supersonic is now used to apply to airplane and rocket 

 flight above the speed of sound. 



