44 
BULLETIN OF THE BUREAU OF FISHERIES 
of fish taken inside the percentage of fish belonging to each age group, and in the 
last two columns the percentage of fish with ocean and stream nuclei. The data 
on the percentage of fish with ocean nuclei and with stream nuclei are also shown 
in Figure 12. In the figure the trend, as shown by the broken line, was determined 
hj twice smoothing the original data by threes," and then further smoothing "by 
eye." A high percentage of fish with stream nuclei is found during the first month 
and a half of the season, but during the latter part of June the percentage of fish 
with stream nuclei decreases rapidly and fish with ocean nuclei constitute from 80 
to 90 per cent of the take after the first of July. The percentages of fish with 
ocean nuclei are not shown in the figure, as they are merely complementary to those 
for the fish with strearn nuclei. 
Table 9. — Composition of collections of fish taken inside the river as regards age groups 
Date 
Percentage with— 
Total percent- 
age with — 
Ocean nuclei in — 
Stream nuclei in- 
Ocean 
nuclei 
Stream 
nuclei 
Second 
year 
Third 
year 
Fourth 
year 
Fifth 
year 
Sixth 
year 
Second 
year 
Third 
year 
Fourth 
year 
Fifth 
year 
Sixth 
year 
May 10 
2. 4 
6.0 
80.5 
49. 7 
82. 5 
11. 1 
34. 1 
72.3 
25.0 
48.0 
52. 7 
24. 1 
7.8 
2.3 
5. 5 
2.0 
4. 2 
3. 2 
5.3 
3.2 
17. 1 
1.3.0 
17.5 
79.6 
20. 4 
7. 2 
3.5.0 
28. 6 
20. 5 
5.6 
2. 0 
I. 2 
1. 1 
2. 4 
10.7 
97.6 
89.3 
100.0 
90.7 
61.3 
94.0 
6.5.0 
90. 1 
82.7 
37.0 
12.0 
14.1 
22.4 
2.0 
28.0 
7.4 
7.3 
12.7 
May 13 
4. i 
1.4 
25.9 
0.7 
May 16 
May 17 and 18 
5.6 
34. 1 
3.7 
9.3 
38.7 
6.0 
35.0 
9. 1 
17.3 
63.0 
88.0 
85.9 
77.6 
98.0 
72.0 
92 6 
92 7 
87. 3 
May 27 
2.3 
4.8 
2.3 
2.3 
13.3 
4.5 
1. 2 
5.0 
4. 1 
.8 
1.8 
May 30 and 31 
1.2 
June 10 
25.0 
7. 1 
15.7 
9.3 
33. 3 
21. 2 
15. 3 
50.0 
16. 7 
29. 5 
3. 2 
6.3 
10.0 
2.0 
June 16 _ _ 
10. 2 
8.7 
5. 6 
2.0 
10.0 
15.3 
June 16 and 17 
. 8 
14.8 
2.0 
5.9 
17.0 
4.0 
.8 
25.9 
47. 1 
25.9 
24.0 
42.0 
33.3 
46.3 
66.0 
59.0 
June 24 and 25 
3.7 
9.3 
5.9 
2.3 
1.6 
2.0 
4.2 
July 3 
July 7 
30. 6 
19. 7 
July 16 
. 5 
July 28 - 
Aug. 5 
20.8 
10. 5 
1.0 
4. 2 
12. 5 
3.2 
4. 2 
1.0 
1.0 
4. 2 
Aug. 6 
6. 3 
22.4 
22. 1 
Aug. 22 
1.0 
5.3 
Sept. 12 
Although it appears from these data that stream nuclei predominate during 
about half of the season, it must not be inferred that approximately half of the total 
number of fish taken during the season are of this type. The fish taken during May 
and June form a comparatively small part of the total pack, although an important 
part, owing to their fine quality. The great bulk of the run occurs during July 
and August. Reliable statistics are not available, but it is probable that, in most 
years, not more than 25 per cent of the total pack on the Columbia River is taken 
during May and June. On this account the percentage of the total pack formed 
by fish with stream nuclei will be much less than the percentage formed by fish 
' This smoothing was accomplished by smoothing independently the series of time values (10, 13, 16, 18, 27, etc.), and the series 
of percentage values (97.6, 89.3, 100.0, 90.7, etc.). The resulting smoothed time values were then paired with the corresponding 
percentage values and the pairs used as coordinates for the determination of the "smoothed" points. 
