UC Irvine

In the SE Bering Sea, sea surface temperatures increased from the late 1970s to the mid-1980s, then decreased. Over the same period, there were inter-annual variations in the water masses surrounding the Pribilof Islands. Subsequent to the mid-1970s, there were changes in the abundance of capelin Mallotus villosus and 1-group walleye pollock Theragra chalcogramma. Use of capelin by both black-legged kittiwakes Rissa tridactyla and red-legged kittiwakes R. brevirostris decreased at the Pribilof Islands subsequent to 1978, as did the use of 1-group pollock in the late 1970s. Availability of fatty fishes such as myctophids, capelin and sand lance decreased after the late 1970s. Beginning in the late 1970s, there was a decrease in the number of chicks produced per nest for both black-legged and red-legged kittiwakes nesting on the Pribilof Islands. Inter-annual variation in the availability of fatty fish was at least in part responsible for variations in the production of chicks by red-legged and possibly by black-legged kittiwakes.