Guillemot Early Breeding Season and New Cooper Island Publications



George Divoky and North Slope Borough Search & Rescue pilot Brian Burke preparing the helicopter for the flight out to Cooper Island June 11.

Fieldwork at the Black Guillemot colony on Cooper Island began in early June, where I began the fifth decade of research on a remote island in a rapidly changing Arctic. Just how rapidly that change is occurring was obvious on the first day in the field, June 11, 2015, when I discovered that egg laying had already begun, with the first egg laid some two weeks earlier than the average date of the first egg over the last four decades. The early laying was a direct result of an extremely early snowmelt in Arctic Alaska that provided Black Guillemots access to nest cavities in late May. A future post will have more details on what the unprecedented timing of this breeding season means for the Cooper Island guillemot colony and in the context of the forty years of observations of breeding chronology that precede it.

I discovered that egg laying had already begun, with the first egg laid some two weeks earlier than the average date of the first egg over the last four decades.

While long-term changes in snowmelt are affecting the start of the guillemots’ breeding season, long-term changes in summer sea ice extent have been changing their breeding success at the end of breeding season.  Two papers examining how the decadal decreases in sea ice extent have affected the guillemots’ ability to feed their nestlings were included in a special issue of the journal Progress in Oceanography containing papers generated as part of the Synthesis of Arctic Research (SOAR).  SOAR is an initiative of the National Oceanic and Atmospheric Administration (NOAA) and the Bureau of Ocean Energy Management (BOEM) and seeks to have researchers collaborate on multidisciplinary analyses utilizing complementary data sets.

Two Recent Publications on Cooper Island Research are Now Available

Effects of recent decreases in arctic sea ice on an ice-associated marine bird

by G.J. Divoky, P.M. Lukacs, and M.L. Druckenmiller
Download the full PDF article

This paper examines how changes in sea ice extent and sea surface temperature have affected Black Guillemot prey availability during the nesting period – comparing a historic (1975-1984) period with a recent one (2003-2012).  The graphical abstract below shows how much summer ice has changed over the past four decades. That loss and the concurrent increases in sea surface temperature have reduced availability of Arctic Cod, the guillemots preferred prey, with subsequent decreases in nesting growth and survival. This paper is featured on the Nature Climate Change website.

Graphical abstract draft with chicks and fish labeled and arrows

Change in the Beaufort Sea ecosystem: diverging trends in body condition and/or production in five marine vertebrate species

by  L.A. Harwood, T.G Smith, J.C. George, S.J. Sandstrom, W. Walkusz, and G.J. Divoky
Download the full PDF article

This paper is a synthesis of trends in five species in the Beaufort Sea (bowhead whale, Arctic char, ringed seal, beluga and black guillemots).   While the first two species appear to be benefiting from recent decrease in sea ice, the others are seeing declines in condition, growth or reproduction. This article is available online for the the Progress in Oceanography Journal.

Cooper Island location

Study area and locations from the article. Cooper Island is 40 km southeast of Point Barrow.

This summer we hope to post weekly updates from the field on the guillemots’ breeding success, polar bear visits, and the challenges in conducting research on an isolated island. You may want to bookmark this site if you want to follow how the guillemots are doing as our study enters its fifth decade.

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Current Sea Ice Status


Sea ice this week.



Sea ice last week.



Sea ice in 2006. The last year of heavy ice.


The Black Guillemots on Cooper Island have seen their nesting success reduced over the past four decades as sea ice decline has reduced the availability of their preferred prey.

Sea ice extent in the Arctic on June 15, 2015 was 9.1 (only one decimal point) million km sq., 10 percent less than the average for that date for 1979-2008. The above images show the proximity of sea ice to Cooper Island currently and for the same week in 2006.

For maps from earlier in the summer see the ice information from National Ice Center.

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Cooper Island Guillemots and Shell’s Chukchi Sea Drilling Plans

The two weeks before I head north to Cooper Island are always an interesting mix of anticipation of the upcoming three-month field season combined with regret at having to leave my family and friends in Seattle. In recent years, as the Arctic continues to warm, there is a good amount of uncertainty as to what the next field season might bring. While the Nanuk cases now protect the Black Guillemots eggs and nestlings from polar bears forced to Cooper Island because of the melting sea ice, the increasingly frequent decreases in prey availability as the pack ice recedes and seawater warms are causing large numbers of chicks to starve in the nests in August.

Recently the 2015 field season took on an additional element of concern as Shell Oil was approved to drill for oil off the Alaskan Arctic coast this summer.  One of the rigs Shell will be using, the Polar Pioneer, is currently six miles west of my house in Seattle. For much of this summer, if all goes as Shell plans, it will be 175 miles west of my cabin on Cooper Island.

Chukchi Sea with Cooper Isalnd and Burger

 As the kayakers who protested the arrival of the rig in Seattle this past weekend made clear, the decision to allow Shell to drill in the Chukchi Sea has the potential of harming the Arctic both directly and indirectly.  Direct harm would come from an oil spill – and according to the BOEM (Bureau of Ocean Energy Management), which approved Shell’s plans, there is a 75% chance of one or more large spills should oil production occur in the lease area.  There is also a risk of a spill from exploratory wells, as the Deepwater Horizon showed, and Shell is proposing to drill six exploratory wells this summer.   The indirect harm would occur if and when the oil is transported to places where it can be used as a fossil fuel and help to increase the level of atmospheric CO2, which is already at a record high of >400 ppm and has contributed to Barrow, Alaska (25 miles west of Cooper Island) now having an annual temperature that is 5°F warmer than in the late 1970s. The melting of snow and sea ice caused by that warming was the primary way the Cooper Island guillemots were being impacted by fossil fuels over the last 40 years.  But it is now clear that the drilling by Shell in the Chukchi Sea could pose a major direct threat to the population.

The magnitude of that threat became more apparent to me this past week as I completed the processing of data files showing the distribution of Cooper Island guillemots in the three months after they leave the island.  By outfitting a small number of guillemots with geolocators at the end of the 2011-2013 breeding seasons and retrieving the units the following year, we can now see where the birds have spent the intervening nine months, as the light-sensitive geolocators record daily sunrise and sunset times that identify a bird’s noon and midnight position within an approximately 30-mile radius.

Shell drill site and Cooper Island

 The map I generated for the eastern Chukchi Sea  and Western Beaufort Sea surprised me for two reasons. The first was how widely dispersed the birds are after breeding. The second was how common they are in proximity to this summer’s drilling location – and in the entire Lease Sale Area 193.   It is important to remember that the above map shows the positions from only 10 birds (on average) monitored each year.  Two hundred guillemots now breed on the island annually, with an additional 50-100 young fledging every year, so the frequency of Cooper Island birds in the drilling area is even higher than shown on the attached map.  It appears that in the fall the majority of the population occupies the area where drilling has been proposed.  The annual replacement of flight feathers occurs during the fall,  rendering the the guillemots flightless for a period of time, making them extremely vulnerable to a spill.

I hope to be out on Cooper Island the first week in June and Shell says its drilling season could begin in early July.  I will be blogging from the field – including posts on Facebook (Friends of Cooper Island) and Twitter (@CooperIslandAK) – that will allow anyone interested to find out what is happening on the island with the guillemots, polar bears and me. My summer will include both retrieving and deploying geolocators, which I now realize are an important part of assessing the potential threats to the Cooper Island Black Guillemots.

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