A quantitative assessment of the diet of the blue shark (Prionace glauca) off Nova Scotia, Canada

Abstract

A quantitative analysis of the stomach contents of blue sharks (Prionace glauca) caught in recreational shark fishing tournaments in Nova Scotia, Canada tested for dietary differences based on sex, maturity and tournament location across 3 sampling years (1999-2001). Of 706 sharks examined, 303 stomachs (43%) were everted, 131 (19%) were empty, 231 (33%) contained food items and 41 stomachs (5%) were not examined. Pelagic teleosts and groundfish were found in 19% and 14% of examined blue shark stomachs, respectively. Stomach fullness did not differ between sexes or maturity category. Differences existed between the diet of immature and mature males as well as between immature females and immature males, suggesting sexual segregation during feeding. The frequency of occurrence of pelagic teleosts and groundfish changed across sampling years. Blue sharks off Nova Scotia appear to be opportunistic predators, consuming a wide range of fish species, mammalian tissues and inanimate objects.