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ESCH AND HAZEN 



2.50 



2.40 — 



2.30 



I 



2.20 — 



2.10 



< 



2.00 — 



1.90 — 



1.80 — 



1.70 



1975 



1976 



1977 



SEASON 



Fig. 13 Seasonal changes in body condition (K-factor) of bass in 

 relation to changes in mean surface temperature. 



dissectable body fat and that as the percent of body fat increases, 

 body condition improves (Gibbons et al., in press). 



Infection percentages were compared in each 0.2-unit K-factor 

 subclass for bass from ambient and thermal locations (Fig. 16). For 

 bass from thermally altered areas, infection percentages were high 

 when body conditions were 1.8 or less. When body conditions were 

 > 1.8, infection percentages were lower, but variably so. The pattern 

 for bass from ambient locations was clear; infection percentage 

 declined beginning at 1.8 and continued to decrease as body 

 conditions improved (the zero infection at 3.0 is believed to be 

 artifact of the small sample size). Attempts to show these kinds of 

 relationships seasonally are ineffective because of relatively small 

 sample sizes in certain seasons in all 3 years. If bass are separated into 

 two groups, however (> 1.8 and < 1.8), and the data for each season 

 for all 3 years are pooled (e.g., spring, 1975—1977), the patterns 

 show the impact of temperature on both infection percentage and 

 body condition (Fig. 17). 



Several conclusions can be drawn from these observations. First, 

 among bass in both thermally altered and ambient locations in Par 

 Pond, there is a clear relationship between body condition and the 



