and one downstream from the areas where fertil- 
izers were applied (Figs. 7-12). At no time was 
fertilizer runoff detected in the stream. 
Early season runoff at breakup was observed 
in 1972. Potassium contents were very high in 
this melting snow-runoff. This study area was 
adjacent to the roadnet, and considerable dust 
from the road was found in the snow (Benson et 
al. this volume). It is generally agreed that dust 
particles in water are a major source of potas- 
sium in water, and are probably the source of 
this early season potassium. 
The contrasts between upstream and down- 
stream stations in 1971 and 1972 are revealing. 
In 1971 flow in this stream was low in late 
season. Between these stations the water spread 
out and was shallow, warmed up, and biological 
activity was high. In 1972, the increased rainfall 
caused increased runoff, deeper water, cooler 
water, and less biological activity. The biological 
uptake of ammonia caused a decrease in soluble 
ammonia between the upstream and down- 
stream sites in 1971. Increased temperatures and 
biological activity caused calcium to precipitate 
between these stations in 1971 (Hynes 1970, p. 
43). In 1972, with increased flow, calcium fol- 
lowed its usual trend of increased concentration 
as the season advanced, and there was little 
difference between upstream and downstream 
sites. 
Large rivers: The calcium, potassium, and 
ammonia concentrations in the Sagavanirktok 
River are shown in Figs. 13, 14, and 15. The 
calcium and potassium levels of this large river 
may be contrasted with the trends observed in 
lakes and small streams in that the levels of these 
ions do not increase during the summer in the 
Sagavanirktok. The lowest ammonia concentra- 
tions we observed were found in the Sagavanirk- 
tok during the summer of 1972. 
Nitrate, phosphate, iron: The minimum 
detection limit for nitrate was 0.01 ppm nitrate 
nitrogen. In all waters in 1971 nitrate was 
usually 0.01 ppm or less. Slightly higher nitrate 
concentrations were observed at most sampling 
sites in 1972. The minimum detection limit for 
phosphate was 0.01 ppm. Most samples had less 
than 0.03 ppm phosphate, with no observable 
seasonal trends. 
67 
2.0. gp 
a (*)I971 (61972 
1.6F "| 
K 2 
ppm . 
0.8} 
4 ° : 'e' . 4 
OA) ar J 
2 ° ° ° 
(@) 4 4 4 4 49. i 
10 20 10 20 10. 20 
Jun Jul Aug _ 
Fig. 7. Potassium content of a small stream, 
1971 and 1972 (upstream). 
T T T a a 
140¢ 
(*)197I 
(o)1972 
120F 4 
} 
lOOF 
Ca gal 
ppm r 
60Fr 4 
40+ : 4 
20r po 4 
+ 
fe) n 1 ai L Say res See 
10 20 lOn20 10. 20 
Jun Jul Aug 
Fig. 8. Calcium content of a small stream, 1971 
and 1972 (upstream). 
4.0 ro T r SSS 
(*)I97I 
3.0F (°)1972 
NH, N 
ppm 2.0F 
OF 1 
o% ° 
Oo J Fe 4 eee 4 ———} 
10 20 10 20 lo}20 
Jun Jul i Aug 
Fig. 9. Ammonia-N content of a small stream, 
1971 and 1972 (upstream). 
