OCCURRENCE OF ARCTIC COD (BOREOGADUS-SAIDA) SCHOOLS AND THEIR VULNERABILITY TO PREDATION IN THE CANADIAN HIGH ARCTIC

We document the occurrence of large schools of Arctic cod (Boreogadus saida) in the Barrow Strait region of the eastern Canadian Arctic duri ng the open water season. Schools were most frequently observed near s hore, often in depressions inside bays. Schools ranged up to 130 000 m l surface area and contained on the order of 4 x 10(8) fish, weighing 12 000 tonnes. Evidence indicates that schools form before the arrival of predators, but when they occur in shallow water, they are often su bjected to intense predation by thousands of seabirds and marine mamma ls, primarily black-legged kittiwakes (Rissa tridactyla), northern ful mars (Fulmarus glacialis), harp seals (Phoca groenlandicus), beluga (D elphinapterus leucas) and narwhal (Monodon monoceros). The reasons for such schooling behavior are unknown.