Feeding Patterns of Greenland halibut (Reinhardtius hippoglossoides) in Flemish Pass (Northwest Atlantic)

Abstract

A qualitative study of the food composition of Greenland halibut (Reinhardtius hippoglossoides) was made by on-board analysis of commercially caught fish in 1992. The fish were caught east of Newfoundland (NAFO Div. 3LM) in unusually deep waters, with an average of 1 040 m. Variations in feeding according to predator size, depth and month were studied. The annual average percentage of empty stomachs was 69%, increasing through the year for specimens over 60 cm. The frequency of occurrence (FO) of food items was used to evaluate the importance of prey groups. Fish (39%), cephalopods (32%) and decapod crustaceans (22%) were the main items, with cannibalism reaching 2%. An abrupt change in diet composition occurred in fish between 60 and 69 cm, from feeding on decapod crustaceans and cephalopods to fish and factory ship discarded offal. The influence of the fishery itself on the diet of Greenland halibut was observed when an important food component in the largest specimens (>60 cm) consisted of offal discarded after fish processing. This study indicates that the FO of the main prey groups bears more relation to the size of fish than with depth.