The ecology of Arctic cod (Boreogadus saida) and interactions with seabirds, seals, and whales in the Canadian Arctic

• Published in: Polar Biology
• Main Author: Matley, Jordan
• Other Authors: Dick, Terry (Biological Sciences), Fisk, Aaron (Biological Sciences) Baydack, Rick (Environment and Geography)
• Format: Master Thesis
• Language: English
• Published: Springer 2012
• Subjects: foraging; diet; stable isotopes; school; predator; food web; migration; kleptoparasitism; niche; diet-tissue discrimination factor; northern fulmar; black-legged kittiwake; glaucous gull; parasitic jaeger; ringed seal; narwhal; beluga; Arctic; Fulmar; Arctic cod; Beluga; Beluga*; Black-legged Kittiwake; Boreogadus saida; Delphinapterus leucas; Fulmarus glacialis; Glaucous Gull; Larus hyperboreus; Monodon monoceros; narwhal*; Northern Fulmar; Parasitic Jaeger; Polar Biology; Pusa hispida; rissa tridactyla; Stercorarius parasiticus
• Online Access: http://hdl.handle.net/1993/8868

This thesis investigates the foraging of Arctic cod (Boreogadus saida) and its predators during the summer in the Canadian Arctic. Findings included the identification of Arctic cod, ringed seal (Pusa hispida), beluga (Delphinapterus leucas), and narwhal (Monodon monoceros) diet shifts in response to seasonal prey availability; calculation of isotopic diet-tissue discrimination factors for Arctic cod, ringed seals, and whales based on local tissue and stomach content sampling; and determination of predatory cues to optimize foraging, such as the presence of schools. Additionally, I quantified seabird feeding and interspecific interactions such kleptoparasitism and found that black-legged kittiwakes (Rissa tridactyla) and northern fulmars (Fulmarus glacialis) captured cod directly but lost many to parasitic jaegers (Stercorarius parasiticus) and glaucous gulls (Larus hyperboreus). Finally, I determined that schools of cod were important prey sources for northern fulmars, glaucous gulls, and whales however non-schooling cod were a significant source for black-legged kittiwakes and ringed seals. October 2012