Seabird predation on Arctic cod during summer in the Canadian Arctic

• Published in: Marine ecology. Progress series (Halstenbek) Vol. 450; pp. 219 - 228
• Main Authors: Matley, Jordan K., Fisk, Aaron T., Dick, Terry A.
• Format: Journal Article
• Language: English
• Published: Inter-Research 29-03-2012
• Subjects: Aerial locomotion; Animal feeding behavior; Birds; Boreogadus saida; Foraging; Fulmarus glacialis; Kleptoparasitism; Larus hyperboreus; Marine; Marine ecosystems; Parasitism; Predation; Rissa tridactyla; Sea birds; Stercorarius parasiticus; Wind velocity; PNW, Canada, Nunavut; PN, Arctic; PNW, Canada, Northwest Terr., Franklin, Parry Is., Cornwallis I
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps09561

Seabirds feed heavily on Arctic codBoreogadus saidaduring the summer in the Canadian Arctic but little is known of the interactions among birds while foraging and the factors that drive feeding behaviour. The objective of this study was to describe the relationship between seabirds and Arctic cod in a productive feeding area distant from breeding colonies. Transect surveys were completed using standardized count protocols to determine the density of seabirds in Allen Bay, Cornwallis Island, Nunavut. Shore-based observation sites determined seabird foraging behaviour associated with the presence of schools and environmental variables. The density of birds (156 birds km−2) was high compared to that of other locations in the Canadian Arctic. Several bird species were more active early in the morning and with winds from the south, possibly due to an increase in Arctic cod feeding on zooplankton at the surface. Northern fulmarsFulmarus glacialisand black-legged kittiwakesRissa tridactylacaptured Arctic cod directly from the water; however, they lost nearly 25% of captures to glaucous gullsLarus hyperboreusand parasitic jaegersStercorarius parasiticus. These kleptoparasitic seabirds benefited the most in Allen Bay obtaining as much as 8 times more Arctic cod than species capturing cod directly. Northern fulmars captured 3 times more Arctic cod from schools, and black-legged kittiwakes captured similar proportions of schooling and non-schooling cod. We conclude that non-schooling Arctic cod are as important as schooling cod as an energy source for seabirds in nearshore areas, such as Allen Bay, during the summer.