Seattle, Wash., June 10, 2009 — After over three decades of conducting summer fieldwork on seabirds in Arctic Alaska one would think that pre-field preparations would be a matter of habit and that that the level of anticipation and anxiety associated with heading off to a remote island would be minimal. But as I prepare to spend three months living at the edge of the continent and pack ice studying black guillemots on Cooper Island, I am reminded of the philosophical observation that no man can step in the same river twice. Anyone who has spent time in the Arctic during the last decade does not need to be a philosopher to see that “all is change”. The Arctic I first visited in the 1970s bears little resemblance to that of the early 21st century. My camp used to consist of one or two small tents, I could arrive in late June just after snowmelt, and in plenty of time to see the start of guillemot egg-laying, and while I always took a shotgun with me, it frequently remained untouched during my stay on the island.
This year the winter snow melted in Barrow in late May continues a long-term trend of earlier snowmelt caused by warming air temperatures in April and May. My two small tents have been replaced by an 8×12 cabin I brought out over the ice from Barrow in early 2003 after polar bears ripped up two of my tents and ran me out of my camp in 2002. Since 2002 bears have become an almost daily presence on the island in late July and August, and I now have to carry a loaded shotgun constantly whenever I am out of the cabin (and keep it close to me when I am in the cabin). This rapid increase in bear activity in recent years is due to their preferred habitat, the Arctic pack ice, undergoing unprecedented decreases in summer and forcing bears to the shores of the Arctic Ocean, where many now spend late summer and fall waiting for the ice to return.
My long-term study of black guillemots, a diving seabird closely associated with pack ice, has shown how a warming Arctic has had major effects on the breeding biology of an Arctic resident. Guillemots need the snow to melt before they have access to their ground-level nest boxes and also need to have their young leave the nest before snow begins to accumulate in late summer. Until the late 1960s the period the ground was snow-free in Arctic Alaska was frequently less than the 80 days of nest access the guillemots need to raise young successfully. Due to warming over the last four decades guillemots now regularly have over 100 days of cavity access. The earlier snowmelt and later accumulation allowed guillemots to prosper on Cooper in the late 20th century as the restrictions of snow cover were reduced. However the same warming that facilitated access to nest sites was increasing the melt of pack ice adjacent to Cooper Island (and throughout much of the Arctic Basin). Black guillemots in the Western Arctic are dependent to a great extent on prey associated with pack ice. They feed in the pack ice throughout the winter and most colonies are adjacent to the summer sea ice. The guillemots primary prey item is Arctic cod, a species that specializes on feeding under and near Arctic sea ice. During the 1970s and 1980s when ice was typically within 20 miles of Cooper Island in August parent birds had little trouble finding enough prey to feed their young. In the last decade early and rapid retreat of the ice from the near shore has meant that guillemot parents find far less cod and as a result try to raise their young on prey that is less abundant and of lesser quality. This has resulted in breeding failures in recent years with many chicks starving in the nest sites or leaving the nests at very low weights.
The changes caused by increasing temperatures in the Arctic have affected my pre-field activities since in April or May. I now need to determine if polar bears have broken into my cabin as they did in the winters of 2004 and 2005. Cleaning up and assessing the damage done by a large curious and/or hungry carnivore in an 8×12 foot box is not a minor chore and best done before the start of the field season. So in late April of this year I went over the ice from Barrow to Cooper Island with my friends Robert Suydam and Leslie Pierce to see if the wood on the cabin door was still in place and the cabin ready for another field season. We were relieved to find that all was well with the cabin and also that the depth of the snowdrifts around the cabin was sufficient to provide me with drinking water for the first part of the season.
I travel to Barrow and Cooper Island late this week and will be sending weekly updates about my observations and experiences during my stay on the island this summer. Since much of what happens on the island is dependent on the retreat of the sea ice I will also attempt to have updated satellite imagery showing ice conditions in the area of Point Barrow and Cooper Island. An early June ice image shows that while there is extensive shore fast ice north of Cooper Island, there is a rather larger area of open water north of that and that the pack ice is composed for relatively small ice floes for this time of year.
Looking forward to another summer in the Arctic and being able to share stories and images from the island.Share This Post