FISHERY BULLETIN: VOL. 87, NO. 4. 1989 



5). Estimated densities ranged from about 0.2 to 

 21.6 fish/m^ X lO*" of water sampled. Lowest 

 catches were noted for surface sets. 



Sockeye salmon were intermediate in size be- 

 tween 0-age fall chinook salmon and spring 

 Chinook salmon smolts. Outmigrant sockeye 

 salmon ranged from 74 to 101 mm FL. About 

 80% of the sockeye salmon were >95 mm FL 

 and, of 96 fish examined, almost all their scales 

 had not yet formed an annulus. Circuli counts for 

 all fish ranged from 8 to 17 and were positively 

 con-elated {R~ = 0.71) with fish length. 



Table 5. — Summary of average catch per unit effort for 

 sockeye salmon smolts caught by fyke nets in spring 1984. 

 No smolts were caught in the shoreline fyke nets. 



Station 



Depth 



Number/h ^ lo'^ Number/m^ x 10^ 



Barge 1 



Barge 2 



Barge 3 



Barge 4 



0.35 

 1.11 

 0.92 



0.22 

 2.67 

 5.20 



0.19 



4.77 



21.64 



0.67 

 1.42 

 0.62 



Distribution of Steelhead Smolts 



Small numbers of juvenile steelhead were col- 

 lected from late April through early June 1984. 

 Most fish had eroded fins characteristic of hatch- 

 ery stocks. Various agencies released approxi- 

 mately 1.1 milHon steelhead smolts into the Co- 

 lumbia River above Priest Rapids Dam in 1984. 

 Almost all juvenile steelhead (34 of 39) were 

 collected in the main river channel (barge 3) and 

 from either the middepth or bottom positions. 

 No steelhead were collected in shoreline fyke 

 nets and only one was collected at a nearshore 

 barge station (barge 4). 



An average of 0.3 to 5.4 steelhead were col- 

 lected/100 h of sampling, depending on the net 

 location (Table 6). Catches were highest from 

 the bottom depth at the midchannel station, 

 where about four fish were collected per m^ x 

 10*^ of water sampled. 



Size of the juvenile steelhead ranged from 165 

 to 241 mm FL. Scales of 14 fish were examined: 

 10 fish were yearlings and 4 were age 2. 



Other Salmonids 



No juvenile coho salmon were captured, even 

 though about 500,000 juveniles were released 

 about 192 km upriver in May 1984 and some 

 were collected by gatewell dipping at Priest 

 Rapids Dam. One juvenile mountain whitefish, 

 Pwsopiion ivilliamsoni, 77 mm FL, was col- 

 lected in late May 1984. 



Distribution Based on Supplementary 

 Sampling 



Chinook salmon were the primary salmonid 

 species collected by electroshocking (Table 7). 

 Numbers of chinook salmon smolts peaked in 

 nearshore areas in early May 1984. Wild 0-age 

 chinook salmon dominated catches in late May, 

 and hatchery-released 0-age chinook salmon 

 dominated in late June. Late-summer migi-ant 

 chinook salmon smolts were also electroshocked 

 in small numbers from late July to early Septem- 

 ber 1983. Steelhead comprised 7% of the total in 



Table 6. — Summary of average catch per unit effort for steel- 

 head smolts collected by barge fyke nets in spring 1984. No 

 smolts were caught in the shoreline fyke nets. 



Station 



Depth 



Number/h x 10^ Number/m^ x io^ 



Barge 1 



Barge 2 



Barge 3 



Barge 4 





 

 



0.21 

 0.24 

 0.55 







1.72 



3.98 





 

 0.62 



Table 7. — Seasonal totals for juvenile salmonids caught by 

 boat electroshocker in shoreline transects. Each of two 400 m 

 shoreline transects was sampled four times daily. 



Species 



784 



