LIMNOLOGICAL STUDIES OF KARLUK LAKE 
419 
maximum of 22 milligrams in one stream ; the surface water of the lake yielded from 
9.5 to 10 milligrams of fixed carbon dioxide per liter. The 22 milligrams per liter 
found in Little Lagoon Creek was about twice the amount present in the other 
streams. This indicates that there is a much larger quantity of calcareous material 
in the drainage basin of this stream than in those of the other streams. 
Table 10 . — Results of the chemical analyses of the stream waters 
[Results are stated in milligrams per liter of water. Tr. means trace. The station numbers are indicated on the map, fig. 1] 
Most of the streams carried a larger quantity of phosphorus, both soluble and 
organic, than the surface water of Karluk Lake. There was also a marked difference 
in the amount of phosphorus found in the different streams. The soluble phos- 
phorus varied from only a trace in Cascade Creek at the falls to a maximum of 0.06 
milligram per liter in Moraine Creek at the lake. The organic phosphorus ranged 
from a minimum of 0.003 milligram in Falls and Cascade Creeks to a maximum of 
0.13 milligram per liter in Moraine Creek at the lake. 
There was also a marked difference in the quantity of both soluble and organic 
phosphorus in the upper courses and in the lower courses of several streams. Such 
differences are shown in Table 10 for Canyon Creek, Cascade Creek, Moraine Creek, 
and the Upper Thumb River. The stations at which the various samples were taken 
are indicated on Figure 1. The water at the mouth of Moraine Creek yielded 15 
times as much soluble phosphorus as that at the upper end of this stream and 7 
times as much organic phosphorus. The quantity of soluble phosphorus was more 
than six times as large at the mouth of the Upper Thumb River as it was above the 
falls in the north fork of this stream. The differences in Canyon and Cascade Creeks 
were not as marked as those in the other two streams indicated above, while a smaller 
quantity of phosphorus was found at the mouth of Falls Creek than at the station 
above the falls in that stream. 
The titratable silica in the various streams ranged from 1 to 3.5 milligrams per 
liter of water. This quantity was larger than that in the upper water of Karluk 
Lake. 
In general, much larger amounts of ammonia, nitrite, and nitrate nitrogen were 
found in the stream waters than in the surface water of Karluk Lake; also considerable 
