4. Tests were run at a minimum level of light intensity to eliminate schooling 

 and group movements. The technique of manipulating the light intensity stimulated 

 downstream movement eliminating tJie necessity of startling or forping the fish into 

 the electrical field. 



5 . The most effective results from the laboratory experiments were obtained 

 at an angle of 40°, a width of field of 2 feet, an electrode spacing of 12 inches with 

 1/2 -inch diameter electrodes. Under these conditions 68 percent of the fish were 

 directed to the collecting channel, as compared with only 16 percent in control tests 

 with power off. 



6. Tne 2 -foot width of electrical field appeared to be more effective than the 

 3 -foot width of field. 



7. With a few exceptions the effectiveness of the 40° and 60* angles of electrical 

 field were not significantly different. The 90° angle of field was least effective. 



8. There were few significant differences between 1/2 -inch and 2-inc.h diameter 

 electrodes. 



9. Electrode spacing appeared to be more important at a 40" angle of electrical 

 field, than at 60° and 90° . 



10. Light intensity may increase the percentage diverted through the effect on 

 schooling behavior and group movement. 



ACKNOWLEDGMENTS 



Thanks are due Mr. Charles Ellis, Supervisor of Hatcheries for the State of 

 Washington, for making available the salmon fingerlings used in these experiments. 

 The cooperation of the personnel of the Waslrngton State Fish Hatchery at Issaquah 

 is also greatfuUy acknowledged. 



Appreciation is expressed for the advice and services of Fishery Research 

 Biologists Robert H. Lander, Galen H. Maxfield, and Robert R. Morrison, and 

 electronics technician Donald L, Thorne. Charles Volz was responsible for the 

 design and operation of the electronic equipment used in the experiments. The 

 electrical guiding research is under the immediate supervision of Dr. Gerald B. 

 Collins . 



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