Five populations ranging from Nova Scotia to the high Arctic are recognized for management purposes based on geographical distributions, genetics and lead isotope data. Some of the populations appear to be at greater risk than others due to over-hunting, and may be threatened. However, knowledge about population structure is insufficient to assess them separately. The Nova Scotia-Newfoundland-Gulf of St Lawrence population was hunted to extirpation by the late 18th century. Sporadic recent sightings of individuals and small groups in the Gulf of St Lawrence and off Nova Scotia are not considered evidence of re-establishment. The South and East Hudson Bay population is believed to number in the low hundreds, although population size and structure are poorly known. Observations from the late 1930s to the present suggest that numbers declined significantly, but the rate of decline cannot be quantified and it is not known whether the decline is continuing. The small population size suggests it may be vulnerable to disturbances and small increases in hunting effort. The total size of the Northern Hudson Bay-Davis Strait population could be as small as 4000-6000 individuals. Its ability to sustain minimum current removals is questionable. Some portion of this population is hunted in Greenland waters. The Foxe Basin population was estimated to be 5,500 in 1989. It is unknown if current exploitation rates are sustainable. Hunting is believed to have reduced the Baffin Bay (High Arctic) population to only a few percent of the number present in 1900. Limited information suggests the current population is small and that a portion of it continues to be hunted at unsustainable levels in the North Water area of Canada and northwest Greenland. However, satellite tracking and genetic information suggests that some animals in this population are resident in the Canadian Archipelago (west Jones Sound and Penny Strait / Lancaster Sound) and are not exposed to over-hunting. Better information is needed on population sizes and composition, seasonal movements, vital rates, and hunting mortality. The biggest threat is over-hunting, particularly on populations that inhabit the southern and northern ends of the species' current range. The species is near to qualifying for threatened status and requires an effective plan to manage hunting. No Management Plans are currently in place for the species. Although quotas have been set in few communities, it is not known if they are adequate to prevent over-hunting.