Variabilities in stomach contents of cod, collected by demersal and pelagic trawl in the southern part of the Barents Sea

Abstract

Samples of Northeast Arctic cod stomachs were collected separately on demersal and pelagic stations at the same date in February 1986 and were analysed for length group 30-40cm. The results indicate that the mean value of the stomach contents weight as well as the food composition are substantially different for the two type of gear. The Spearman rank correlation coefficent (rs = 0.109;t = 0.363;P > 0.1) is not significant based on frequency data calculated from the diet of cod gathered by demersal and pelagic stations. These results question the accuracy of the consumption estimates which is based on a combination of field stomach contents weight and laboratory gastric evacuation rate studies. Therefore the mean value of the stomach contents weight should be distributed on the fishing gears, in addition to seasons, subareas, fish size and time of the day.