Merking av sei i Nordland sommeren 1921 : beretning avgit til fiskeridirektøren
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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.