Balaena mysticetus (Okhotsk Sea subpopulation)

Sea of Okhotsk from Shantarskiye Zaliv east to Zaliv Shelikova, Gizhiginskaya Guba and Penzhinskaya Guba (Moore and Reeves 1993, Rice 1998). The absence of bowhead sightings on any of the Japanese-Russian systematic surveys of cetaceans in the Okhotsk Sea conducted in 1989, 1990, 1998, 1999, 2000 and 2003 (Miyashita and Dorosehnko 1990; Miyahsita and Berzin 1991; Miyashita et al. 2000, 2001; Miyashita 1999, 2004) tends to confirm that animals from this subpopulation are rarely found outside those four known areas of concentration.

Bowhead whales have been seen regularly during Russian surveys in the northeast and southwest Sea of Okhotsk. Berzin et al. (1991) reported bowhead sightings every year from 1982 through 1990, except 1985, with up to 72 whales apparently seen on one day. Doroshenko and Ivannikov (2003) reported 48 bowhead whales sighted during a not especially intensive survey conducted in 2001. 

However, there are no reliable estimates of abundance. Berzin et al. (1990) believed the individuals in the southwest Okhotsk Sea to number at least 250–300 animals, while Vladimirov (1994) estimated the subpopulation at 300–400 whales for the entire Okhotsk Sea. These values appear to be based primarily on the numbers seen, without evaluation of effective search effort. The proportion of the subpopulation that comprises mature animals is unknown. A value of 44% has been estimated for the Bering-Chukchi-Beaufort Sea stock of bowhead whales. The absence of bowhead sightings on any of the Japanese-Russian systematic surveys of cetaceans in the Okhotsk Sea (referred to above) tends to suggest that the subpopulation is small.

Little is known about the specific ecology of the Okhotsk Sea bowhead whale subpopulation. Unlike other bowhead whale subpopulations, this one inhabits an area that is ice-free in summer.

The seasonal distribution of bowhead whales in general is strongly influenced by pack ice (Moore and Reeves 1993). During the winter bowhead whales occur in areas near the ice edge, in polynyas, and in areas of unconsolidated pack ice. During the spring these whales use leads and cracks in the ice to penetrate areas that were inaccessible during the winter due to heavy ice coverage. During the summer and autumn they concentrate in areas where zooplankton production is high or where large-scale biophysical processes create local concentrations of calanoid copepods (Finley 1990, Finley et al. 1998). 

The International Whaling Commission has protected bowhead whales from commercial whaling since its inception in 1946 and there is no aboriginal subsistence whaling exemption for Okhotsk Sea bowhead whales. The species, including this population, is protected under Russian law through its inclusion on the Russian national Red List. This species has been included in CITES Appendix I since 1975.  The species listed in Appendix I of CMS.