Table 1. Sample sizes of beluga whales from fifteen geographic strata in the north Pacific: A resident population (Cook Inlet) and a separate small resident group (Yakutat Bay) in the Gulf of Alaska, six summering areas in the Bering, Chukchi, and Beaufort Seas, three summering areas in the Okhotsk Sea, and four locations along the northbound spring migration routes.

Some of these strata have previously been identified as demographically separate management stocks based on mtDNA. While almost all samples were screened for microsatellites sample numbers for these nuclear markers indicate only those samples that yielded genotypes at six or more loci.

Region	Geographic Strata	Label in Figs 1 & 2	Stock	MtDNA	microsatellites	MtDNA	Total
				n	n	(Meschersky et al. 2013)
Gulf of Alaska	Cook Inlet	1	Cook Inlet	133	78		133
	Yakutat Bay	2	Cook Inlet	8	8		8
Bering-Chukchi-Beaufort	Bristol Bay	3	Bristol Bay	140	129		140
	Norton Sound	4	E. Bering Sea	191	73		191
	Kotzebue Sound	5		119	64		119
	Kasegaluk Lagoon	6	E. Chukchi Sea	579	533		579
	Mackenzie Delta—Amundsen Gulf	7	E. Beaufort Sea	101	96		101
	Anadyr	8		46	44	37	83
Okhotsk	western Kamchatka	9		4	4	14	18
	Sakhalinskiy Bay	10		12	1	106	118
	Shantar—Udskaya Bay	11		10	10	46	56
BCB Migration	eastern Chukotka	A, B		10	9		10
	Little Diomede Island	C		11	10		11
	Point Hope	D		55	35		55
	Barrow—Kaktovik	E, F		16	13		16
	*cow-calf pairs			9	9		9
	All Locations			1444	1116	203	1647

*These represent the individuals from each of nine known cow-calf pairs sampled together that were screened but excluded from subsequent analysis.