Merkeforsøk med sei på Vestlandet sør for Stad 1972 - 1974

Abstract

In 1972, 1973 and 1974, 6291 young saithe were tagged on the Norwegian west coast south of 62°N. By the end of 1976, 1094 (17.4 per cent) were reported recaptured. Of these, 87.7 per cent were found in the North Sea region. Of the saithe which had left the tagging area, 79.1 per cent were recaptured in the North Sea and 17.3 per cent on the Norwegian coast north of 62°N. Most of the recaptures in the North Sea were made north of 57°N and east of 2°E. The recovery rate was less than half of what would be expected from the exploitation rate on saithe in the North Sea region. This is caused partly by non-return and non-observation of tags and possibly by shedding; but the tagged saithe also seem to suffer a higher mortality rate than normal, in some cases shortly after tagging, but probably also over longer periods. A basically similar presentation of the results of these experiments is given in English by JAKOBSEN (1978).