Table 3. — Percentages of salmonids of age- 

 group I captured at various depths in rela- 

 tion to total area sampled in upper Mayf ield 

 Reservoir, April 1964 to June 1965 



Milling was extensive; 57 percent of all 

 salmonids caught entered the nets from the 

 upstream side and 43 percent from the down- 

 stream side. 



The horizontal and vertical distribution of 

 225 salmonids of age- group I taken in the 

 trawl (table 4) was similar to that of the 

 salmonids taken by the gill nets during the 

 same period (table 5). 



Trawls captured 438 salmonids, of which 

 213 were age-group 0. These fish were caught 

 at all trawling depths, but most were captured 

 at night in the upper 3.7 m. of water and 

 when the turbidity was high. Table 6 shows the 

 distribution of 0- group salmonids captured by 

 the trawl. 



Table 4. — Horizontal and vertical distribution 

 (percentage based on catch per unit of 

 effort) of 225 salmonids of age-group I 

 captured by trawling in upper Mayfield 

 Reservoir, 1965 



[ Dashes indicate stations not sampled 

 because of insufficient depth ] 



Table 5. — Horizontal and vertical distribution 

 ( percentage based on catch per unit of 

 effort) of 1,511 salmonids of age-group I 

 captured by gill nets in upper Mayfield 

 Reservoir (April 12 to June 17, 1965) 



[Dashes indicate stations not sampled 

 because of insufficient depth] 



1 No sample collected. 



Table 6. --Horizontal and vertical distribution 

 (percentage based on catch per unit of 

 effort) of 213 salmonids of age-group 

 captured by trawling in upper Mayfield 

 Reservoir, 1965 



[Dashes indicate stations not sampled 

 because of insufficient depth] 



EFFECT OF PHYSICAL ENVIRONMENT 

 ON CATCH 



Substantially larger catches were taken by 

 the gill nets and the trawl during spring 

 runoff, probably because the increased tur- 

 bidity made the sampling gear less visible and 

 perhaps because more fish were available due 

 to a flushing action. 



