Polar bears are not evenly distributed throughout the Arctic, nor do they comprise a single nomadic cosmopolitan population, but rather occur in 19 relatively discrete subpopulations. There is however an uncertainty about the discreteness of the less studied subpopulations, particularly in the Russian Arctic and neighbouring areas, due to very restricted data on live capture and tagging.
The PBSG subpopulation status table and status assessments have been regularly updated for decades. The first status table was published after the 11th meeting of the PBSG in Copenhagen in 1993. Status reviews have traditionally been discussed and updated every time the group members have physically met. From now on the status assessments will be updated as new information becomes available, and a new status table was agreed upon prior to the Moscow Meeting of the Parties in December 2013.