The importance of minimum temperatures during the critical winter and 
spring months make it necessary to obtain a complete temperature 
record during this period. Temperatures lower than those shown in 
table & may have occurred in the study streams. Continuing observa- 
tions will be made to obtain a complete record of minimum water 
tempetfatures. 
Salt Water Temperatures 
Salt water temperatures measured three inches below the surface were 
taken periodically during August and September, 1952, in the Twelve- 
mile Arm area near three of the streams. The average salt water 
temperature for August was 59.3° F., for September 54.4° F. Salt 
water temperatures were, respectively, 7.3° and 4.6° higher than cor- 
responding mean fresh water temperatures in Maybeso Creek; 4.2° and 
4.4° higher than Harris River; and 4.8° and 4.5° higher than Indian 
Creek. Although these salt water records are not complete, it appears 
that upstream migrating salmon are exposed to lower fresh water tempera- 
tures than to salt water temperatures during this period. 
Relationship between Water Temperature and Other Factors 
Data from all streams indic.te a strong direct relationship between 
air and water temperature. Rising air temperature resulted in rising 
water temperature; decreasing air temperature resulted in decreasing 
water temperature. Davidson, et al (4), found that daily variations, 
as well as seasonal trends, in stream temperature were closely associa- 
ted with changes in air temperature. Pritchard (15) reports that 
water temperatures of McClinton Creek, B. C., are directly correlated 
with the air temperatures in the region. 
Fig. 12 shows graphically the relationship between mean monthly water 
temperature and mean monthly air temperature for Maybeso Creek. The 
relationship is very similar in all study streams. Air temperatures 
during May through September were several degrees warmer than cor- 
responding water temperatures. Mean temperature differences between 
air and water were quite uniform in all streams (table 9). Water 
temperature during October was generally warmer than air temperature. 
Mean monthly water temperature of all streams is shown graphically 
in fig. 12 also. The figure reveals the modifying influence of 
lakes on stream temperature. Old Tom Creek, whose watershed contains 
two lakes, was found to be slightly warmer during most winter months 
than streams without lakes. Water temperatures during summer months 
also appear to be modified slightly. 
An inverse relationship was found to exist between water temperature 
and stream stage. Fig. 12 shows the relationship between mean monthly 
water temperature and stream stage in Maybeso Creek. A lowering 
stream stage resulted in an increase in water temperature, and vice 
versa, On all four study streams the highest water temperatures were 
associated with the lowest stream levels; the lowest water temperatures 
oy ae 
