Translation Series No.1211

changes annually appears to follow this current, whereas others reach the
Baltic Sea proper by way of the Ilandsea. The further course of the migration
can no longer be followed on hand of currents. Whereas the salmon frOm the
rivers Lule and Oulujoki'remain predominantly around Gotland, a very large
part of the fish from the Indalsâlv move into the soUthern Baltic Sea.
Beginning with the second year, spawning migrants can always be found during
July/August in front of the home rivers.
Nothing has been known hitherto about the sojourn in the Baltic
Sea. It appeared possible that the fish, after leaving the Gulf of Bothnia,
searched out immediately the final feeding grounds and remained there, or
that they move continuously during feeding and that they have no definite
feeding grounds. In the end an annual round through the eastern Baltic Sea
until the spawning migration had been assumed. Table 22 gives a weak hint
as regards these questions. If the salmon of the Indalsev remain during
Lp. 282]
their sojourn in the Baltic Sea proper on an average farther to the south
than the fish from.the Gulf of Bothnia, then not all can make a circuit
through the eastern Baltic Sea . or wander annually around Gotland. In other
words, a map that shows the recovered salmon within a limited period in a
definite distribution in the entire Baltic Seà proper, does not indicate
that every one of these salmon must have visited during its sojourn the
various regions of the area occupied by the population. Even if a rather
far flung migration is carried out; it is not to be assumed that those
salmon who lived in the extreme south had been previously frequently in
the far north or had moved there. This does not exclude, of course, that
individual fish do not make lengthy wanderings.
.
A feW results of my own tagging experiments support this assump-
'tion (Fig.'24 a'to c). In November 1960 15 salmon Were tagged near Bornholm,