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In 2000, the International Whaling Commission conducted a global assessment of beluga whales, Delphinapterus leucas. Following this assessment, five beluga stocks were recognized in Russian Far East waters: Western Chukchi-East Siberian Sea, Anadyr Gulf, Shelikhov, Sakhalin-Amur, and Shantar. This paper provides a revised assessment of beluga abundance, distribution, and population structure in the Russian Far East. This region encompasses the Okhotsk Sea, and the coastline of the Chukotka Autonomous Region (CAR), which includes the western Bering, western Chukchi, and eastern East Siberian seas. Published results of genetic analysis are updated with our original unpublished data. Based on information available to date, we propose recognizing seven beluga stocks in the Russian Far East. Five stocks in the Okhotsk Sea: 1) Sakhalin-Amur, 2) Ulbansky, 3) Tugursky, 4) Udskaya, 5) Shelikhov, and two stocks in the CAR: 6) Anadyr, and 7) Bering-Chukchi-Beaufort (BCB). Natural and anthropogenic threats to these stocks are described and include ice entrapment, over-fishing of key prey, live captures for aquaria, bycatch in fisheries, exposure to effluent, and seismic and military activities., Introduction In the Russian Far East, the beluga, Delphinapterus leucas, or white whale, occurs in the Okhotsk Sea and along the coastline of the Chukotka Autonomous Region in the western [...]

The monodontids--narwhals, Monodon monoceros, and belugas, Delphinapterus leucas--are found in much of the Arctic and in some subarctic areas. They are hunted by indigenous subsistence users. In the past, some populations were substantially reduced by commercial hunting and culling; more recently, some populations have declined due to uncontrolled subsistence hunting and environmental degradation. Monodontids are impacted increasingly by human activities in the Arctic including ship and boat traffic, industrial development, icebreaking, seismic surveys, competition with fisheries, and alteration of habitat due to climate change. Since comprehensive reviews in the 1990's, substantial new information has become available on both species and on changes to their habitat as a result of human activities and climate change. Thus NAMMCO and partners undertook an updated review in 2017. The review recognized 21 extant beluga stocks, 1 extirpated beluga stock, and 12 stocks of narwhals. The available information on each stock regarding population size, depletion level, current and past removals, and trends in abundance was reviewed to determine status. Concern was expressed where the lack of information prevented reliable assessment, removals were thought to be unsustainable, or the population was deemed at risk of declining even without direct removals by hunting. Beluga stocks of greatest concern are the small stocks in Ungava Bay (possibly extirpated), Cook Inlet (ca 300), St. Lawrence Estuary (ca 900), and Cumberland Sound (ca 1,100), and the stocks with uncertainty in Eastern Hudson Bay and the Barents-Kara-Laptev Seas. Narwhal stocks of greatest concern are those in Melville Bay and East Greenland., Introduction The family Monodontidae is comprised of the narwhal, Monodon monoceros, and the beluga or white whale, Delphinapterus leucas (Rice, 1998). These two species are found in much of the [...]

Full mitochondrial genomes were assembled for 12 recently sampled animals from the Svalbard bowhead whale (Balaena mysticetus) stock via high-throughput sequencing data, facilitating analysis of the demographic history of the population for the first time. The Svalbard population has retained noticeable amounts of mitochondrial genome diversity despite extreme historical harvest levels. Haplotype and nucleotide diversities were similar to those estimated earlier for other bowhead whale populations. The reconstructed demographic history was in accordance with a boom–bust scenario, combining a slight Pleistocene population growth 25 000–35 000 years ago and a Holocene decline. Employing a mutation rate of 3.418 × 10–8 substitutions per site per year, the time to the most recent common ancestor for the mitochondrial genomes of the contemporary Svalbard bowhead whales was estimated to be 68 782 (54 353–83 216) years before the present. Based on 370 bp fragments of the D-loop region, significant genetic differentiation was detected between all extant bowhead whale populations across the circumpolar Arctic. Thus, the Svalbard bowhead whales can be regarded as a population with its own genetic legacy. [ABSTRACT FROM AUTHOR]