Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 5
Comments: Only five discrete populations exist: the largest is that in the western Arctic (Bering, Chukchi, and Beaufort Seas); others are in the Davis Strait, Hudson Bay, Spitsbergen region (Svalbard-Barents Sea), and Sea of Okhotsk (DeMaster et al. 2000). There has been doubt that the Davis Strait and Hudson Bay stocks were actually separate populations, but genetic evidence shows that they are not only separate, but that the Hudson Bay stock is actually more closely related to the western Arctic population (Maiers et al. 1999). The small population in the Sea of Okhotsk may be separable into two groups: those that summer in the northeastern Okhotsk Sea and those that are found in the Shantarskiye region (DeMaster et al. 2000).