DAUBLE ET AL.: SPATIAL DISTRIBUTION OF JUVENILE SALMONIDS 



120 180 240 300 



Distance from Benton County Bank (m) 



360 



Figure 5. — Cross-seetional distribution of 0-age fall chinook salmon ( u = 

 6.281) caught in shoreline and barge fyke nets during spring 1984. Note: 

 horizontal scale is reduced. 



Overall, fyke net catches of 0-age chinook 

 salmon ranged from an average of 0.3 fish/h at 

 the Benton County shoreline (shoreline 1), to 3.5 

 fish/h at barge 4 (Table 2). A peak catch of 152.8 

 fish/h occurred on June 14 from the bottom depth 

 at barge 4. This quantity corresponded to 5.6 

 fish/100 m^ of water filtered through the net. 

 Based on water volume, catch per unit effort was 

 greatest at the Grant County shoreline (shore- 

 line 2). 



Little change in fish size was noted for 0-age 



chinook salmon collected with fyke nets in April 

 and May; 80 to 90% of the fish collected were 

 <45 mm fork length (FL) (Fig. 6). However, in 

 June the 0-age chinook salmon collected in the 

 shoreline nets were smaller than those collected 

 in the barge nets. In June, the barge nets col- 

 lected mainly hatchery fish >80 mm FL, while 

 60% of the shorehne net totals were wild fish 

 <70 mm FL. 



The relative proportion of 0-age chinook 

 salmon caught at the various fyke net stations 



80 

 70 



30 

 20 

 10 







90 

 80 

 70 

 30 

 20 

 10 







L ^ 



(a) 



^ 



Atx^ I 



April 

 n = 396 



May 

 rn n = 1112 



^^t'ThT^ I I 



June 



n = 1487 



f^^ 



-...jmm 



(b) 



m 



April 

 n = 9 



May 

 n = 276 



June 

 n = 67 



I I I I I I 





40 50 60 70 40 50 60 70 40 50 60 70 80 90 



Fork Length (mm) Fork Length (mml Fork Length (mm) 



Figure 6. — Length-frequency of 0-age fall chinook salmon collected with fyke 

 nets: a) barge sets and b) shoreline sets. 



781 



