Translation Series No.1211

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In this manner were obtained the values of significance in Table
[P. 249]
10. Since W (t) equals 0.05 for all.fishing regions, we have here very
probably genuine differences in the catch. It is possible that they stand
in the majority of cases in relation to the wind speed. .
• The results for the net fishery (Table 11) have an entirely
different aspect. For the fishing region 5 better catche s. were recorded
for lower wind 'speeds. The probability that this concerns genuine differ-
ences in the catchis 97.6 per cent. In the other fishing regions also the
values are higher for winds under 4 on the Beaufort scale than for stronger
winds. No test for significance was made, because only few individual•
values are available for strong winds, which are based mostly on catches
of fewer than 100 salmon. The material on hand, however, gives the impres-
sion that differences in yield that are probably caused by wind can be dem-
onstrated for all fishing regions in the Baltic Sea proper.
Before the possible causes for this phenomenon are considered,
we shall first examine the relation between wind direction and yield of
catch. At winds of less than 5 on the Beaufort scale it is nôt possible
to demonstrate significant differences in line catches in relation to
wind direction. For wind speeds above 5.13eaufort only fishing region 5 can
be investigated, because there are too few values for the other regions.
The test for significance with the data of column 5 was carried out by con-
sidering the deviationà of the yields for west wind against those for east '
wind; as Well as the values for north and south winds. The•probability that
the catch differences are significant amounts to 81 per cent concerning
north wind catches, to 68 per cent in regard to east wind catches and 54
per cent for south wfnd catches. The differendes are thus not significant.
At the other fishing grounds . the , west wind catches are• greater for '