High up in the Arctic Circle, Olivier Chastel begins his working day by scanning the horizon for polar bears, rifle at the ready. “In 25 years I’ve never had to use it, but you can’t be too careful,” he explains. There can’t be many conservationists who go birdwatching while armed, but the danger to life from bears in Svalbard — the largest island of the Norwegian polar archipelago — is so high that it’s a legal requirement.
Every day between mid-May and early July, Chastel and his colleague Frédéric Angelier, a specialist in avian stress physiology, use a 5-metre rubber dinghy to visit the Krykkjefjellet kittiwake colony, where around 400 pairs of black-legged kittiwakes (Rissa tridactyla) come to nest each year. “Typically, we stop the boat just in front of the beach and scout the place before landing,” says Chastel. “We see polar bears coming for the bird eggs, just like us, and often they arrive before us. But most of the time they leave in peace.”
For 25 summers, Chastel, a biologist, has returned to the same spot to monitor these migratory seabirds, which travel 4,000–5,000 kilometres each year, from the Canadian Arctic to Svalbard’s western Kongsfjorden coastline, to breed. Since 2000, Chastel has been studying the impact of synthetic contaminants as well as mercury on the birds’ physiology, a project supported by the French Polar Institute in Plouzané as part of a long-term partnership with the Norwegian Polar Institute in Tromsø.
Angelier (pictured with Chastel, below), who works alongside Chastel at the Centre for Biological Studies of Chizé in Villiers-en-Bois, part of the French National Centre for Scientific Research (CNRS), comes to the site to study how contaminants affect the telomeres at the ends of the birds’ chromosomes, a biomarker of health. The two researchers have been close friends and colleagues since 2001, when Angelier became Chastel’s first PhD student.
The changes they have seen in the birds and their landscape during that time are stark. “There used to be sea ice in the fjord in May when we arrived for the start of the season, but we haven’t seen any sea ice since 2009,” says Chastel. “The ecosystem has changed dramatically, and I worry about the future.”