It lost more than 40 per cent of its area in just two days at the end of July, researchers said on Thursday.

A study published this week has painted a grim picture of the future of polar bears, particularly in the low Arctic.

The work of dozens of federal scientists and Inuit observers, it describes a vast ecosystem in unprecedented flux: from ocean currents to the habits and types of animals that swim in it.

The two TU-160 Blackjack bombers crossed the North Pole and approached Canada from western Russia, but remained in international airspace before departing, according to Norad.

Canada has had some sort of northern affairs ministry for decades, but it's always been wrapped in with other areas such as resource development or Indigenous concerns.

"The Kremlin has a growing interest in dominating the Arctic, where it sees Russia as in competition with Canada," says the report's author.

The scientists drew 18 ice cores of up to 2 metres long from four locations and saw visible plastic beads and filaments of various shapes and sizes.

"More work needs to be done," says Sen. Dennis Patterson of Iqaluit.

A winning bidder is to be chosen in 2022 and the first planes are to arrive in 2025.

A new survey by Statistics Canada shows women and girls in the North face higher rates of violent crime than those in the rest of the country.