A new study is published on polar bear behaviour near ice breaker operations.

Today is Arctic Sea Ice Day. When we think of the Arctic the polar bear is one of the first species we think of. It is an iconic Arctic species but one that is threatened by sea ice loss. The Arctic has experienced record lows in sea ice over recent years. This June set yet another record low for Arctic sea ice extent. The National Snow and Ice Data Centre in the United States reported the sea ice to average a mere 10.6 million square kilometers in June. This may sound like a lot but it is the lowest average sea ice extent for the month of June since the Centre’s records began in 1979.

Polar bears depend on the sea ice, they are in fact marine mammals. They hunt and breed on the sea ice. They prefer to hunt along the ice-edges of ice leads and polynyas (open stretches of water within the pack ice), searching for ice seals -their main prey.

But polar bears are facing greater challenges for survival, especially as global warming leads to greater ice loss each year combined with increased human activity in remote Arctic regions.  A lot of work has been dedicated to understanding how polar bears are coping with diminishing sea ice but little has been published on how these iconic Arctic marine mammals are affected by human activities, particularly shipping and oil and gas exploration.

Last month SMRU Consulting North America’s Frances Robertson co-authored a paper in the journal Arctic examining polar bear behaviour near ice breaker operations in the western Arctic.

This was the first paper to report on polar bear behaviour near operating ice-breakers. The paper summarized behavioural observations collected by biologists stationed aboard an ice breaker in the Chukchi Sea in 1991. The ice breaker was supporting oil and gas exploration activities at two remote oil prospects.

Frances and her co-authors found that while polar bears commonly reacted to the presence of the ice breaker their reactions were brief and the bears often returned to what they had been doing. The bears most commonly stopped what they were doing to watch the ice breaker -a behaviour biologists refer to as vigilance. These observations are similar to others that suggest polar bears are not overtly disturbed by human-related activities.

So the good news is that the polar bears observed in this study did not appear to be overly disturbed by the presence of the ice-breaker. But in the face of greater and greater sea ice loss polar bears will find it increasingly difficult to find prey and in these tougher circumstances we still don’t have a good understanding of how polar bears will be impacted by our activities. Oil and gas exploration continues in parts of the Arctic and tourism is also seeing an increase -this year cruise ships plan to start travelling through the Northwest passage for the first time.

Whether polar bears will be able to successfully adapt in time to the changing Arctic landscape remains to be known. In order to limit our impact on them we need much more data, particularly contemporary data on their behavioural responses, including foraging and denning success in the vicinity of industrial developments. In the mean time this study has added substantially to the small pile of data that is available for assessing our impacts on polar bears.

Smultea, MA, J Brueggeman, F Robertson, D Fertl, C Bacon, RA Rowlett and GA Green (2016) Polar Bear (Ursus maritimus) Behavior near Icebreaker Operations in the Chukchi Sea, 1991. ARCTIC 69 (2):  177–184, doi:http://dx.doi.org/10.14430/arctic4566 

 

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Featured photo credit: Markus Karasti from Icebreaker Oden during the 2015 Petermann Expedition in Greenland. August 2015