Despite its small area, the Arctic Ocean is considered an independent ocean, because …

The Arctic Ocean is considered independent, since it is located between two other oceans, but differs from them in the structure of water and currents. It is the shallowest and shallowest ocean. It is also the only ocean where the deep-sea shelf would occupy less territory than coastal zones. Depth cannot become a feature that distinguishes seas from oceans, since there are seas in the Pacific Ocean that reach depths of more than 9 km, which is deeper than the rest of the oceans.