Translation Series No.1211

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U7,) tdL
comparablenece of the yields of cruises that had been selected as eapteee
per unit effort.
Let us examine once more the age composition of the Catches in
Table 33 in order to discover the cause of the fluctuations in the catches
yelw-at,s
of the sea year classes A.1+ and Ae2+. In 1958 the average yeeke-la-eet of
• yewgmolt
of 1955 as A.1+ contrasts with the good y arls-set of smolt of 1955
as A.2+. For this reason the share of the sea year class A.1+ WaA onky 54 per
cent. A year later appear together the good yeaele act of smolt of 1957
as A.1+ and the average of 1956 as A.2+. A.1+ accounts therefore for 72
per cent of the catches. In 1960 the sea year class A.1+ is represented
ye,v-éless yeew-
by the poor yearic-cet of smolt of 1958. In comparison with the good yecela
CA.45
Set of 1957 (A.2+) it yields a share of only 49 per cent. In 1961 the av-
erage ycartc7 act of smolt of 1959 as A.1+ in comparison with the poor one
of the year 1958 made up 77 per cent of the catches. In the yeax 1962 the
[P. 314]
good yearls-cet of smolt of 1960 furnished even 90 per cent of the catches,
de,ss
whereas the sea year class A.2+ is represented by the average yeario sot
of 1959. The percentage of the sea year classes in the catches is thus
y eev
alwgys dependent on the relative strength of the yecTlezzeefs of smolt.
5.3.1.3. The salmon with spawning marks
During their spawning migration, the salmon probablycease to
feed already before they enter the rivers. It has, already been stated that
the development of the gonads is accelerated during this period. Since the
fish also have to supply the energy for the spawning migration and for the
spawning, all body reserves are being mobilized. Among other things, there
is a degradation of Substance on the scales (T. H. Jgxvi and W. J. M.
Menzies 1936): This involves a more or less complete resorption along the