ABSTRACT 



The effectiveness of one type of narrow direct -current electrical field in 

 diverting salmon fingerlings in flowing water was explored experimentally in relation 

 to (1) the angle of the electrical field relative to the direction of water flow, (2) the 

 width of the electrical field (distance between rows of electrodes), (3) the spacing 

 between electrodes, and (4) the diameter of the electrodes . The electrical conditions 

 were held constant at a voltage gradient of 1 volt/cm . , a pulse frequency of 8 pulses/ 

 sec, and a pulse duration of 40 milliseconds with a square wave form. 



It was determined that under the conditions of these experiments the maximum 

 effectiveness occurred at a 40° angle of electrical field and a 2 -foot width of electrical 

 field with 1/2 -inch electrodes spaced 12 inches apart. With few exceptions, the 40° 

 angle of field was not significantly more effective than the 60° angle of field, and the 

 1/2 -inch diameter electrode was not significantly more effective than the 2 -inch 

 diameter electrodes . The 2 -foot width of field appeared to be more effective than 

 the 3 -foot width of field. The results of variation in electrode spacing were greatest 

 at a 40° angle of electrical field. 



CONTENTS 



Page 



Introduction 1 



Methods and materials 1 



Experiments 8 



Discussion 39 



Summary 40 



Acknowledgments 41 



Literature cited 42 



