30 
BULLETIN OF THE BUREAU OF FISHERIES 
ducted at a distance the average size of the catch usually will be large and the number 
of deliveries necessarily will be small. When fishing close to the plant the size of catch 
may be large or small, but the number of deliveries will usually be higher than when 
fishing distant grounds. The average total catch per boat per week, therefore, is 
probably a more trustworthy measure of abundance than either of the foregoing. 
However, one criticism applies to it that applies to the average size of catch, namely, 
that the shift in the fishing ground keeps the trend from showing the true decline in 
abundance, so that all decreases that are shown are minimum. 
In studying the average weekly catch per boat the data were treated similarily to 
those of the average number of deliveries, the average catch per week being assumed 
to be the average for each day within the week. As with the study of the number of 
deliveries, all of the weekly averages previous to 1927 were multiplied by the factor 
0.786 to allow for the 36-hour weekly closed season of recent years. The results of the 
computations are given in Table 6. 
Table 6. — Comparisons of weekly average catches per boat with a standard catch curve 
Month 
Geometric means of the weekly average 
catches per boat expressed as percentages 
of the standard curve 
Geometric means expressed as percentages of 
1928 mean 
1921 
1922 
1923 
1924 
1925 
1926 
1927 
1928 
1929 
1921 
1922 
1923 
1924 
1925 
1926 
1927 
1928 
1929 
GROUP I 
June 
July 
August 
September 
Total 
Number of boats - 
64.3 
32! 8 
99.0 
83.4 
61.9 
44.1 
112.0 
6L3 
66.9 
106.7 
81.2 
78.6 
64.0 
82.1 
124.6 
59.7 
120.7 
26.6 
92.3 
75.8 
135.9 
104.3 
61.6 
64.1 
71.0 
84.8 
84.5 
99.2 
64.0 
80.2 
32.5 
95.2 
165.0 
76.1 
68.8 
51.2 
117.1 
84.1 
96.7 
53.5 
132.6 
89.6 
95.8 
81.1 
126.3 
81.9 
122.8 
.65.5 
147.4 
188! 5 
32.3 
109.2 
76.4 
212.2 
126.4 
72.9 
64.6 
110.9 
102.8 
100 
100 
100 
100 
94.9 
32.8 
148.7 
200.0 
61.4 
87.6 
80.6 
102.0 
114.3 
69.2 
81.4 
77.5 
75.4 
107.6 
99.8 
100.9 
125.3 
140.4 
85.0 
100 
95.2 
2 
14.0 
30.0 
3 
24.0 
28 5 
25.5 
7 
30.4 
19 
31.7 
26 
33.1 
33.4 
Average tonnage 
group n 
June 
83.9 
136.0 
101.2 
63.9 
85.6 
60.0 
82.8 
106.5 
82.0 
70.1 
46.7 
122.8 
81.4 
54.8 
163.1 
79.1 
165.9 
144.4 
.60.2 
104.4 
85.6 
177.3 
100 
100 
100 
100 
115.8 
99.3 
78.2 
349.2 
July 
August 
September 
Total- _ 
93.7 
72.0 
73.9 
93.9 
126.8 
97.4 
100 
127.1 
Number of boats 
Average tonnage 
23 
27.8 
23 
30.7 
21 
31.1 
18 
35.2 
GROUP m 
221.6 
176.6 
127.0 
110.3 
144.9 
87.8 
37.2 
78.6 
110.0 
43.7 
32.2 
46.5 
46.7 
41.1 
36.5 
474.3 
429.9 
348.0 
236.2 
352.7 
240.6 
79.6 
191.3 
301.4 
93.6 
78.2 
127. 4 
100 
100 
100 
July 
August 
Total ( 
169.6 
114.6 
69.0 
40.1 
41.0 
413.9 
279.5 
168.3 
97.8 
100 
Number of boats— 
2 
31.5 
30.5 
J.o 
30.1 
7 
32.5 
Average tonnage 
ALL BOATS 
June 
157! 3 
116.1 
76.7 
74.7 
6l! 7 
71.7 
105.0 
63! 4 
57.5 
109.8 
67.1 
85.8 
131.6 
85.3 
187.7 
183.1 
133.4 
71.1 
97! 3 
124.7 
100 
100 
100 
100 
104.5 
80.1 
135.4 
July 
August 
September 
Total 
106.5 
72.3 
74.6 
94.9 
142.8 
96.9 
100 
127.2 
Number of boats 
36 
28.3 
57 
31.1 
65 
33.3 
56 
33.7 
Average tonnage 
'■'T™ 
Figure 15 gives the comparisons with the standard curve (fig. 16) for Group I. 
It will be noted at once that 1921 is low in every case, but this is not believed to 
indicate necessarily a lack of abundance for two reasons : First, because the two boats 
for which data are available in 1921 were exceedingly small (Table 6) ; second, because 
