Figure 2. — Method of measuring fork length of sockeye smolts by pricking graph paper. Margin of graph paper 



from headboard is 10 mm. 



Originally, a drop of clear Karo syrup''' was 

 used as an adhesive agent for the slides, but 

 the natural mucus from the scales proved to 

 be a better adhesive. 



Scales were examined to determine growth 

 and age connposition so that brood year 

 (year egg is fertilized) and the annount of hold- 

 over in the lakes could be determined. The 

 scale-reading machine gave an image with 

 variable magnification. Ages were recorded 

 as 1-check (or annulus), 2-check, or 3-check, 

 depending upon the number of annular growth 

 bands shown by the spacing of the circuli. 

 Generally, smolts from Little Kitoi Lake de- 

 parting in the spring with 1, 2, or 3 checks, 

 and referred to as 1-, 2-, or 3-yr.-old 

 fish, had been spawned about 20, 32, or 44 mo. 

 (months) previously. 



To compute condition factors, samples of 

 about 30 smolts were taken from Ruth and 



Trade names referred to in this publication do not 

 imply endorsement of commercial products. 



Little Kitoi Lakes each week during the 1962 

 migration, transported to the laboratory in 

 2-1. (liter) polyethylene bags, and measured 

 and weighed individually to the nearest milli- 

 meter and the nearest 0.1 g. (gram). 



Stomachs of fish collected to determine 

 condition factors were examined for food con- 

 tents with the aid of a dissecting microscope. 

 Organisms were identified to the lowest 

 taxonomic group possible- -often determined 

 by the state of digestion of the organisms. 



Biological Environment 



No detailed plankton studies were made on 

 Ruth Lake before it was treated in 1955. Dur- 

 ing the 1955 field season, a few plankton tows 

 were made in various lakes in the Kitoi Bay 

 area. Tows were made at comparable depths 

 for a standard towing time with a 20-mesh 

 Wisconsin net. The plankton was allowed to 

 settle in a 55-cm.3 (cubic centimeter) bottle 



