Polar Bears Searching for Sea Ice: The GoPro Film and the Science Behind It

Arctic Bear Productions shot this film of polar bears swimming through open Arctic water entirely on a GoPro HD HERO3+. The camera rides at the waterline, so you see the bears the way a seal would: a broad white head, paws paddling hard and long stretches of sea between the floes. The film was released in June 2014 and made a simple point about a hard problem. Each summer, polar bears have less sea ice to hunt from.

Who made the GoPro polar bear film

Arctic Bear Productions is the studio of the Emmy-winning wildlife cinematographer Adam Ravetch and the Canadian documentary filmmaker Sarah Robertson. Ravetch also made Arctic Tale with National Geographic and Paramount Pictures. The swimming footage came out of the non-profit Arctic Exploration Fund, which Arctic Bear Productions supports. The project had backing from WWF and Rolex and worked in cooperation with the US Geological Survey. Its idea is to put cameras on wild animals so that they film their own lives.

The GoPro film on YouTube runs just under three minutes and is embedded below.

Why polar bears need sea ice

The polar bear (Ursus maritimus) is classed as a marine mammal, and with good reason. It lives on frozen seawater, not on land. Ringed seals are its main prey, and bearded and harp seals are hunted too. The bear waits at breathing holes or stalks seals hauled out on the ice. The ice is its hunting platform. When the ice breaks up in summer, many bears are pushed ashore, where they live mostly off stored fat for months.

Adult males usually weigh 300–800 kg and measure 2–2.5 m long. Females weigh 150–300 kg. That body needs a lot of blubber, and a polar bear gets nearly all of it from seals caught on the ice.

How far can a polar bear swim?

Polar bears are strong swimmers. They paddle with their big front paws at up to about 6 km/h and can dive for up to three minutes. One study of long-distance swims found that the average trip lasted 3.4 days and covered about 154 km. USGS researchers working with collared bears report that the animals do not seem to stop and rest during these swims.

Long swims cost a lot of energy, though, and they become more common as the gaps between floes widen. A bear crossing open water is not hunting. Every kilometre between the shore and good seal habitat is paid for out of its fat reserves.

Polar bear numbers and research in Alaska

Scientists estimate that there are 22,000–31,000 polar bears in at least 18 subpopulations across Canada, Greenland, Alaska, Russia and Norway's Svalbard. The IUCN lists the species as Vulnerable. In 2008 the United States listed it as threatened under the Endangered Species Act.

The USGS Alaska Science Center has studied the Southern Beaufort Sea population since 1985 and also works on the Chukchi Sea bears shared with Russia. Its findings track the change in the ice. Over the last three decades, sea ice off Alaska has become thinner and more broken. Southern Beaufort Sea females have moved many of their maternity dens from the ice onto land, and in some areas bears now spend more time ashore. From 2014 to 2016, USGS fitted adult females with GPS video collars for 8 to 12 days each April to watch how they move and feed.

More polar bears and Arctic ice

Our second look at the GoPro footage focuses on the camera work. For people who work with Arctic sea ice, see the Inuit mussel gatherers in Race Against the Tide. For ice of a very different origin, see the collapsing iceberg arch in Newfoundland. Icebergs break off glaciers on land, while sea ice freezes from the ocean itself.