The numbers of beluga, the white whales of Alaska, have halved in 13 years.
1,000m
The depth of which belugas are capable of diving, though they spend the summer in shallow bays and estuaries and the winter under pack ice.
Beluga whales have lived for around 30 years in the wild.
Belugas are the only whales that can bend their neck
There are five main populations:
Bering
Chukchi
Okhotsk Seas
High Artic
west Greenland
Hudson Bay
James Bay
Gulf of St Lawrence