| dc.description.abstract | An experiment of marking saithe (Gadus virens) was undertaken
in 1921 and was performed in two districts in Northern Norway during
june and july, viz. in Gildeskaal in the "skjærgaard" outside the mouth
of the Salten fiord (lat. about 67 degrees N) and in the Hadsel fiord which
separates the Lofoten from the Vesteraalen islands. See chart. At the
former locality 1000 young (3-5 years) fish were liberated 24. june
to 1. july, at the last named place 1119 big fish (5-10 years old). The
sizes are given in fig. 2. The percentages of recapture up till now
(Oct. 1925) are 6.10 for the small and 7.03 for the big fish. The
extent of the migrations undertaken by the marked fish may be seen
from the chart. Especially interesting are the two recaptures in southern
Norway during the following spring, clearly demonstrating the wide-roaming
nature of the saithe. It is, on the other hand, very remarkable
how many fish have stayed for many months in the vicinity of the
place where they were set free. Particulars concerning the recaptures
in point of time and distance travelled are found in the tables pag.
11, 12 and 13, where each fish exclusive of those which have travelled
less than 20 kilometres, are denoted by a figure indicating its
size, in italics if the migration has been to the northward, in heavy
type if it has travelled southwards, the distance being denoted by the
column wherein it is placed.
The marks used were of the silver-coin type for the smaller and
of the Danish bone button type with brass plate for the big fish, in
both cases fastened to the gill cover. The fish were mostly caught
by seine, and were bought from the fishermen. The cost of the
experiment including hiring of vessel and crew, purchase of the fish
and payment of rewards (2 1/2 krone each) amounted to nearly 6000
krones or about £ 240. | en_US |
