Alaska pollock, Walleye pollock, pollock, Минтай.
The population structure of North Pacific pollock is complex and scientific understanding is evolving. In Russia, West Bering Sea west, West Bering Sea Navarinsky, Sea of Okhotsk, and Sea of Japan pollock stocks are considered reproductively isolated from one another, albeit with some inter-migration between them, and are addressed separately from one another by the Russian authorities for purposes of stock assessment (Federal Fisheries Agency, Kamchatka Branch 2020); (Kotenev and Glubokov 2007). Russian fishery managers also recognize that there are fish that originate in the Japanese EEZ harvested in Russian waters (i.e., a separate Japanese Pacific stock) (Ovsyannikova 2012).
Within these groupings, the degree of differentiation among various populations is nuanced. Complications in elucidating pollock population structure include life histories that entail different habitats for spawning, overwintering, and feeding; larval drift from one region to another; and different population dynamics at low and high abundance (Kotenev and Glubokov 2007); (Grant et al. 2010).
The West Bering Sea appears as area 1 in this map of Russian Far East fishing areas, and the Navarinskiy population resides in its eastern half, east of longitudinal Meridian 174ºE. This population of pollock, the second largest in Russian waters, migrates from the East Bering Sea over to the west to feed (Federal Fisheries Agency 2020); (TINRO 2020).