Immigration and emigration of cod in the spawning areas of Lofoten and Møre

Abundance estimates of the spawning stock of north east Arctic cod have in recent years been given on the basis of acoustic surveys. Migration in and out of the surveyed areas during investigation has been considered as a possibly major source of error in the estimates. By studying the migration of tagged cod in the spawning grounds of Lofoten and Møre between 1975 and 1981, it was found that the main immigration to these spawning grounds is compleeted by March 20 and that considerable emigration starts around April 10. It is thus concluded that the most facourable time to estimate the spawning stock, when taking into acount migration alone, is between these dates.