Normal are some of them are secretive and elusive animals in the world's oceans.

The leads provide passage for thousands of these mysterious ways.

Each summer, they travel 1000 kilometers north, navigating through the ice to reach rich fishing grounds.

More whales travel along the edge of the ice, where it meets the open sea to search for the openings of leads.

It's a hazardous journey.

As mammals, they need air to breathe, and if the ice closes above them, they could suffocate.

They're looking for holes in the ice where they can surface.

A single breath will last them for 15 minutes.

The further they travel, the harder it becomes to find holes in the ice, the statue of breath and then travel on but ahead.