Translation Series No.1211
Translation Series No.1211
Translation Series No.1211
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
- 150-<br />
November and April of every fishing period a different method has been<br />
selected for the present case. At first glance the series of measurements<br />
for a season do not show any Considerable differences in the frequency<br />
distribution. The existing changes must be considered to have been caused<br />
principally by conditions of growth. Therefore the idea suggests itself<br />
to assume that the shares Of the two sea year classes in the transition<br />
zone of a series of measurements for all investigations of a season are<br />
almost equal. For testing this assumption the curve of the frequency dia-<br />
[P. 51 8 ]<br />
gram for November 1957 has been shifted until it coincided with the curve .<br />
for the distribution of.lengths of January 1958 (Fig. 35). Consequently<br />
it could be demonstrated that the series of measurements for November and<br />
January show about the same composition. The sea year class AJ.2+ of the<br />
series of measurements for April as a whole does not fit very well the<br />
series of measurements for April. This must be attributed to the smaller<br />
amount of growth of the older fish (see . 5.4.P.) and the selectivity of the<br />
nets. The gap between the two sea year classes thus becomes smaller.<br />
[p. 319]<br />
In Table 40 has been inserted the age distribution of the sea<br />
year class A.2+ in the transition zone, that has been obtained through the<br />
examination of scales. With the aid of these values can be ascertained<br />
now the age composition of the remaining series of measurements. If one<br />
shifts, for example, the series of measurements for November 1957 in such<br />
a way that coincidence is obtained With the distribution of lengths of<br />
January 1958, then there is seen a difference in lenghts of 4.0 cm between<br />
November and Jannaxy. Compared with the values in Table 40 this means that<br />
the salmon from Noveffiber 1957 belong exclusively to the age group A.1+ up<br />
to a length of 70.9 cm (2-cm-group 70). Of the 2-cm-group 72, 3 per cent<br />
- of the measured -fish belong into the age group.A.2+, of the 2- cm,group<br />
5. Per cent belong to to the. age group A.2+, of.that of 76, 14 percent,
Change language