Monster Seminar JAM - When the Arctic Becomes Subarctic: Northern Alaska Seabirds Respond to Climate-Driven Changes in Ichthyofauna
Dr. George J. Divoky, University of Alaska - Fairbanks
Over the last three decades, the western Arctic has experienced a rapid increase in atmospheric temperatures with major effects on the snow and ice environments that dominate the region. The decrease in the summer ice extent has greatly altered the marine environment utilized by the region's seabirds, which provide some of the only indications of the rapid environmental change occurring in the area. The Black Guillemot, an arctic species which flourished in the region in the 1970s and 1980s, experienced declines in population size and breeding success after 1990 when the rate of pack retreat accelerated. Concurrently, the Horned Puffin, a subarctic species most abundant in the Bering Sea and rare in northern Alaska before the late 20th century, expanded its breeding range from the central Chukchi to the Point Barrow region. This alteration in the region's avifauna reflects a transition from an arctic marine environment, dominated by a pack ice that supported arctic cod, to a subarctic environment with apparently increasing numbers of nearshore schooling fish, such as capelin and sand lance. Thirty years of observations from Cooper Island, near Point Barrow, will be used to demonstrate this transition and provide speculation on how the region will be affected by the continued pack ice reduction.
Date and Time:
January 12, 2006,
11:00 am - 12:30 pm