Foreløpige resultater av merkeforsøk på kysttorsk i området Møre-Helgeland.

Abstract

Results from previous tagging experiments at the Møre-Helgeland coast in 1956, 1957 and 1964 indicated negligible mingling between the coastal cod populations at the Møre and Helgeland coast, but some migration from Nordmøre to Sunnmøre. In the present paper results from coastal cod tagging experiments in this area in 1964, 1975, 1979 and 1980 are presented and compared with earlier investigations. During these years a total of 2443 cod were tagged. In the Sunnmøre experiments (1964, 1975, 1979, 1980) from 21 to 43% of the tagged fish were recaptured during the first three months after tagging. In all the other experiments, the recapture in the first three months was less than four percent. The yearly recapture percentage (after three months in freedom) was of the same magnitude at Sunnmøre and Nordmøre, but significant smaller at the Helgeland coast. All the experiments show that most of the immature coastal cod migrate only very short distances, but a spawning migration from Nordmøre to Sunnmøre and even further south is indicated and also a feeding migration backward to the nursery grounds. These experiments confirm the earlier findings that mingling between the coastal cod at Møre and at Helgeland is negligible.