Translation Series No.1211

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whereas the share was 70 per cent in September/October and even 88 pert
cent in May/june. After this result we may ahmune that the share of sal-
mon with empty stomachs gives an indication of the availability of food.
Therefore all results will be correlated in the following investigation
with the total number of the salmon examined.
6.3.2. Différences on the fishing grounds •
Since the size of the weight of the stomach contents depends
on the season, only such data can be used in the compaxison of different
fishing grounds that take such facts into account. The data on hand orig-
inate frOm the fishing grounds 4, ,5 and 6. From the fishing ground 4 data
are available only for the months September (1962, 1963) and October (19 6 1,
1963). Data from the other two fishing grounds are very scarce as fax as
they apply to the same months* and fishing periods. For this reason means
[p. 340•
have been'calculated froM the values of all years and their seasonal course
is given in Fig. 39. The values from the fishing grounds 5 and 6 show good
agreement from December to April. In contrast, the salmon-had in October
1957 near Bornholm more than twice the amount of food in their stomachs
than had the fish'of the Danzig Deep. The values for October from the fishing
ground 4 (Gotland) agree.well.with thoEe from Bornholm.
• AlthoUgh it is not possible to obtain differences in the food
weight of a salmon that are unambiguously dependent on the fishing ground,
there are found certain variations in regard to the composition of the food
on the individuar fishing grounds (Table 51).
On.ths fishing ground 6 it is true that the sprat predominates
in the food, but it is represented to a smiller extent than on the Danzig
• Deep. It is also found that.Belone, Ammodvtes and even the mysids can form