In regions like the Arctic, living creatures have to adapt to cold, but also to the lack of plants and trees that provide oxygen. So how do they breathe?
The conditions that make living in the Arctic so harsh also prevent the trees from surviving there. And even though trees produce oxygen through a process known as photosynthesis, they are not its main producers. 50 to 80% of oxygen actually comes from phytoplankton, microscopic single-celled organisms.
That explains why we can breathe normally on the open sea, in the Arctic, and other regions without a single tree to be seen.