The first four species have been added to the Northwest Territories Species at Risk list since the act was put into place in 2010.
The species at risk secretariat says the Boreal caribou, the Peary caribou, and a plant called the hairy braya are now considered "threatened" species.
The polar bear is listed as a "species of special concern."
Not going to change harvest: wildlife council
Larry Carpenter, chair of the Wildlife Management Advisory Council, supports the additions to the list, but says it won't change how hunters harvest.
"They all know there is restrictions with the Peary caribou from the community of Sachs Harbour and Ulukhaktok," said Carpenter, who lives in Sachs Harbour. "Also, with regards to the polar bear, there is no change as they've already been listed, as I said, under the federal Species at Risk Act."
As for the hairy braya plant, it's added to the list as a "threatened" species because it's only been found in the Northwest Territories at Cape Bathurst and Baillie Island. There are no other known populations of the plant anywhere else in the world.
"Threatened" status means a species is likely to become endangered if nothing is done. "Special concern" status means the species is at risk of becoming threatened or endangered because of biological factors or external threats.
A management plan for the polar bears and a recovery strategy for the other species are being developed over the next two years.