| dc.description.abstract | In the preceding chapters it is demonstrated that the Norwegian-Icelandic
herring tagging experiments have met with success. When properly
handled the herring is capable of withstanding the shock of tagging,
and this first successfully executed herring tagging experiment in European
waters is certainly encouraging. Herring tagging is now being
done in several European contries, with the use of different kinds of
external tags and it is demonstrated that the herring also can stand up
to this treatment.
It is further shown that a herring shoal must be regarded as a temporary
phenomenon, for the shoals evidently disperse after a time, the
fish later reforming themselves into new ones.
Another important result of the taggings is that tagged spring herrings
appear in the catches in the large-herring district, and an intermixture
between large and spring herring definitely takes place. If this
feature continues to manifest itself, the morphological differences observed
(Rasnmussen 1940) (Rundstrøm 1941) need further explanation.
An outstanding feature which may be stressed as being of particular
importance is that transoceanic migrations also take place to a considerable
extent, this being in direct support of Fridriksson's theory,
(Fridriksson 1944).
From the results already obtained through this tagging experiment
it is strongly recommended that this work be continued and, if possible,
extended. As the herrings in the northern waters are only caught commercially
during limited fishing seasons, difficulties are encountered in
the very interesting problem of fixing the routes of the migrations, but
attempts will be made to find and mark herrings in the open sea in the
close seasons in an attempt to clear up this special point. | |
