|Scientific Name:||Mesoplodon stejnegeri|
|Species Authority:||True, 1885|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor(s):||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.|
|Reviewer(s):||Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)|
There is no information on global abundance or trends in abundance for this species. It is not believed to be uncommon but it is potentially vulnerable to low-level threats and a 30% global reduction over three generations cannot be ruled out (criterion A).
|Range Description:||Stejneger's beaked whales are found in continental slope and oceanic waters of the North Pacific Basin, from southern California, north to the Bering Sea, and south to the Sea of Japan (presumably including at least the southern Okhotsk Sea – Mead 1989; MacLeod et al. 2006). This appears to be primarily a cold temperate and sub-arctic species, and this is probably the only species of the genus common in Alaskan waters. It is most commonly stranded in Alaska, especially along the Aleutian Islands. Also, there have been a large number of strandings (at least 34) from along the Sea of Japan coast of Japan, and many fewer along the Pacific coast. The large peak in strandings in this area in winter and spring suggests that the species may migrate north in summer (Mead 1989; Yamada 1997).|
Native:Canada (British Columbia); Japan; Russian Federation; United States (Alaska, California, Washington)
|FAO Marine Fishing Areas:||
Pacific – eastern central; Pacific – northeast; Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There are no estimates of abundance, but the species does not seem to be rare, especially off the Aleutian Islands and in the Sea of Japan. It has been hypothesized that there may be a resident subpopulation in the Sea of Japan and southern Okhotsk Sea (Yamada 1997, Kakuda and Yamada 2001).|
|Habitat and Ecology:||Stejneger's beaked whale ranges in subarctic waters, mostly beyond the edge of the continental shelf, in slope and oceanic waters (Houston 1990; Loughlin and Perez 1985). They are presumably deep divers, feeding in the mesopelagic and bathypelagic zones, mainly on squids of the families Gonatidae and Cranchiidae. Examination of stomach contents supports this idea (e.g., Yamada et al. 1995).|
Stejneger's beaked whales were hunted in a Japanese fishery, along with Cuvier’s beaked whales. They are not presently the main targets of any hunt.
In the past, some individuals were taken in the Japanese salmon driftnet fishery in the Sea of Japan and in driftnets off the west coast of North America. Entanglement in fishing gear, especially gillnets in deep water, is probably the most significant threat.
This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006).
As a cold water species, Stejneger’s beaked whale may be vulnerable to the effects of climate change as ocean warming may result in a contraction of the species range as it tracks the occurrence of its preferred water temperatures (Learmonth et al. 2006). The effect of such changes in range size on this species is unknown.
Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk.
|Conservation Actions:||The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.|
|Citation:||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. 2008. Mesoplodon stejnegeri. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 25 May 2015.|