Jökull - 01.12.1969, Page 141

Fig. 2. The development of herring concentrations and temperature at 20 m in July 1962. —
Black squares: dense fishable herring concentrations. Wide hatching: large number of small
schools. Norraw hatching: scattered small schools.
Icelandic herring was very similar except at
the end of the season in early September when
the Norwegian herring was predominant in
the catches. The landings during the summer
season 1962 amounted to 324,000 tons or 14
higher than in any previous year. This record
herring year is especially interesting for two
features. The fluctuation in sea temperature
that took place off the north coast in July
probably indicates the hydrographic conditions
necessary for the herring if it is to remain on
the north coast fishing grounds during the
middle and second half of the summer. In
addition it must not be forgotten that feecling
conditions in that area (i.e. concentrations of
C. finmarchicus) were better than in any pre-
vious year since systematic investigations began
during the late forties. These two factors in
correlation with the high landings in 1962 gave
a very definite clue to better understanding
of the areal fluctuation of the landings coming
from the north coast herring fishing grounds
off the north coast proper.
1963
One of the rnain features of the herring
migrations to the north coast of Iceland in
1963 was the failure of the eastward migration
of the Icelandic herring to this area. It is
interesting to note that cold surface water with
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