of seine-caught and shocker -caught tagged 

 fish were recovered. This illustrates 

 that shocker -caught fish suffered no sig- 

 nificantly different harnn from the method 

 of collection than did the seine-caught 

 fish. Such an electrofishing apparatus 

 could be used to capture live, unharmed 

 salmon for a variety of purposes. 



The initial cost of an electrofishing 

 installation for tag recovery would be 

 approximately $1,500. This would pro- 

 vide for a battery- starting generator, a 

 pulsing and control unit, the electrode 

 systems necessary for covering both 

 banks of a river, and the supplemental 

 switches and wiring to complete the 

 installation. However, if such a unit 

 captured even one high-seas tagged salmon 

 that would not have been captured other- 

 wise, the cost would be justified. Under 

 the conditions of use described here and 

 with proper off-season storage, the life 

 of the generator and pulsing vuiit should 

 be well over 10 years, materially re- 

 ducing the cost per year. In addition, use 

 of the apparatus for other live-fish collect- 



ing purposes would further justify the 

 initial cost of the instrument. 



After a short period of indoctrination 

 and experience in the field, say 1 week, 

 one man at each station would be suffi- 

 ciently proficient in the operation and 

 use of the apparatus to proceed inde- 

 pendently with its operation. Malfunction 

 of the pulsing unit in the field, once the 

 particular model is perfected, should be 

 negligible. At the time this experiment 

 was performed, the pulser, a new proto- 

 type, had been field-used only for 5 months, 

 and still contained some imperfections. 

 These have been corrected and the unit 

 has since been operating without mal- 

 function under more rigorous field condi- 

 tions than those encountered in this experi- 

 ment. 



On the basis of the results achieved in 

 this experimental operation, it is felt 

 that further use and development of the 

 technique is warranted, provided that 

 sinnilar extrinsic factors, such as the 

 reduced commercial fishery and the value 

 of the recovered tag, exist. 



