Translation Series No.1211

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. A
r i" 'MAY etkeiS
classes consist of different--yearta, but they show an extensively
by-boet yetw•-c&sses
uniform growth in the . sea. On the other hand, the yeaele-eete contain fish
of the same age, but of very variable growth. From the point of -view of
C.11, 5% C.
the study of the stock we shall investigate the brood year's-se-43-, because
we are interested in the number of the fish of one population. Wé analyse
the sea year classes on account of the growth.
cLtses
5.3.1.1. The brood year t -s-se4e
In Table 31 the percentage composition of the catches has been
CetekeS
recalculated as the corrected line eaetuxes per unit effort of Table 15
in order to make possible quantitative comparisons. To begin with, it can
-4ew-ekts
be established that a -year-l-s-ae-t can be represented in the catches for a
maximum period of eight years. The first of the fish,to be captured are
those that emigrate from the river already after one year, and that were
thus in the first year of stay in the sea. During the following four •
years are added to these those salmon that lived for two, three, four or
even 5 years in the river. The oldest of all the fish ekamined waenine
years old and belonged in the-age groUp 3.6. The fish thus remain at Most
for six years in the Baltic Sea.
However, the salmon do not enter iMmediately ifter.reeping the
Baltic Sea into the exploited phase. There axe only - very few fish that
are caught already in the first year of their stay in the Baltic Sea.
Their share in the total catch lies in general below one per cent. Only
during the third year after hatching is the caught share in the year%t
cc% more than one per cent and after the seventh year it .1a1ready lies
again below one per cent. In this connection each year- 1-&-e-e4 becomes ef-
fective . only during five fishing periods. However, it plays a decisive role .