The Arctic Basin Ecozone is a true oceanic ecozone in that it touches almost no land except the north coast of Ellesmere Island. The undersea geography is dominated by the Canada Basin, which plummets to an average depth of about 3 600 metres. The Canada Basin extends from the Beaufort Sea almost to the North Pole, where it is bounded by the Lomonosov Ridge, a submarine mountain range rising to 1 000 metres below the ocean surface. Near the southern margin of the permanent ice pack, the Mackenzie River discharges a considerable plume of fresh water into the Beaufort Sea in the neighbouring Arctic Archipelago Ecozone.
The climate is extremely cold and dry. In January, mean daily temperatures range from -30 to -35°C. In summer, the mean daily temperature rises only to a chilly 5°C. Annual precipitation ranges from 100 to 200 mm -- sparse compared with St. John's, Nfld., Canada's precipitation capital with 1 500 mm a year. And yet, against these most extreme conditions, there is life in Canada's Arctic.