Large numbers of adult salmon have been tagged in a variety of i-rays 

 for the purposes of tracing their further actions and destinations j how- 

 ever, little investigational work has been directed toward determination 

 of the effects of the tagging operation itself on the subsequent behavior 

 and condition of che fish. This neglect could be harmful^ since the tag- 

 ging effects influence the accuracy of results obtained from tagging exh 

 periraehts . 



In order to appraise these effects on red salmon spawiing in Bristol 

 Bay streams 3, an- experiment was' propdsed for 19h9 on a stream of ^such ^all size 

 that it could be under almost constant surveillance, so that any differences 

 of behavior and condition between tagged and untagged fish could readily be 

 noted. Hidden Greek,, a tributary to Brooks Lake on the Naknek River system, 

 was chosen for the purpose. It was accessible, open in character, could be 

 surveyed easily, and was of representative size and length for the Brooks 

 system. Flow was approximately eight cubjc feet per second, and length from 

 the mouth to a beaver dam that formed an impassable barrier was two and one- 

 eighth miles. 



'^'his stream was first surveyed physically, and later divided into half- 

 mile intervals with station markers, A trap was installed at the mouth, 

 blocking passage of all fish to the stream. Plans included tagging and re- 

 leasing approximately 200 spawners, simultaneously releasing a like number 

 of untagged fish, one tagged fish accompanied by one vintagged, so that dis- 

 tribution would be equal. Tagging was done with Peterson tyoe plastic discs, 

 connected by a nickel pin below the dorsal fin. 



On August 17, tagging began at l:l5 pm. on the first group trapped 

 (163 fish), of which 82 were tagged. Tagging of the group was completed at 

 2;00 pm. and the trap opened. By 5sl5 a second group, numbering 231 fish 

 had been handled, of vhich ll5 were tagged, making a total of 197 each tag- 

 ged and untagged. 



Immediately upon completion of tagging, two men started up the stream 

 on survey. They covered all of the area up to the beaver-dam barrier, arriv- . 

 ing there at 7;50 pm. On the following morning they surveyed back down to 

 the trap, which had been closed to prevent passage of other salmon. 



On the first survey, about 80 fish were noted directly above the trap, 

 apparently resting, or undergoing orientation after handling. Between 

 these fish and the half-mile station, the other salmon were observed grouped 

 in schools of from 8 to 20, all of which were moving upstream. Beyond the 

 half-mile station, the salmon were more dispersed, occurring in groups of 

 two and three, but still moving about. 



The survey of the following morning revealed a large number of fish 

 paired and beginning nest excavations, A diminished upstream movement was 

 evident, and very few schools were noted. 



1, 



