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In recent years, due to increasing sea temperatures and ice cover loss, some subarctic and temperate species are seen more often in Arctic waters, including some cetacean species (e.g., Higdon & Ferguson, 2009; Víkingsson et al., 2015; Moore, 2016). The North Pacific right whale (Eubalaena japonica) is listed as "Endangered" by the International Union for Conservation of Nature (IUCN); it is one of the most endangered whale species in the world that has failed to recover after intensive commercial whaling in the 19th and 20th centuries (Brownell et al., 2001). Both historically and in recent times, the sightings of this species in the eastern North Pacific have been mostly concentrated between 40° and 60° N (Cooke & Clapham, 2018; Figure 1). In the western North Pacific, no encounters were registered north of Cape Navarin (62.27° N) according to 19th and 20th century whaling catch and sighting records summarized by Clapham et al. (2004); however, maps of takes by American whalers (Townsend, 1935) did show a few in June and July near Chukotka (approximately at 63 to 64° N). Tomilin (1962) mentioned that right whales ranged north up to Anadyr Gulf, possibly based on the Townsend maps, but Sokolov (1963) reported that the species rarely occurred north of the Commander Islands. In recent years, encounters in the western North Pacific occurred in the Okhotsk Sea, off eastern Kamchatka, Kuril, and Commander Islands south to 57° N (Ovsyanikova et al., 2015).
In this note, we report an encounter with a North Pacific right whale in eastern Chukotka, far north of its typical range. The right whale was sighted for the first time 7 August 2018 in Penkigney Bay on the eastern coast of the Chukotka Peninsula (64.85° N, 172.96° W; Figure 1). The right whale was encountered from a small (4.5 m) inflatable boat during a daily research trip dedicated to the study of a local humpback whale (Megaptera novaeangliae) feeding aggregation. The trip was part of a cetacean research expedition conducted in August-September 2018 in southeastern Chukotka.
When encountered, the right whale was approached, and photographs were taken of flukes and both sides of the animal's head for individual photoidentification (Figure 2). These photographs were compared to a photo-identification catalogue of right whales previously encountered in...