Eubalaena japonica (Northeast Pacific subpopulation)
|Scientific Name:||Eubalaena japonica (Northeast Pacific subpopulation)|
|Species Authority:||(Lacépède, 1818)|
Subpopulation of Eubalaena japonica (Lacépède, 1818). The taxonomy follows the view of the International Whaling Commission (IWC) Scientific Committee (IWC 2004) and Convention on Migratory Species, which recognize right whales in the North Atlantic, North Pacific and Southern Hemisphere as three distinct species in the genus Eubalaena, namely E. glacialis (North Atlantic right whale), E. japonica (North Pacific right whale) and E. australis (southern right whale), based mainly on the mtDNA phylogenetic analyses of Rosenbaum et al. (2000).
In most of the scientific literature prior to 2000, including previous Red Lists (e.g. Baillie and Groombridge 1996), all Northern Hemisphere right whales are treated as the single species E. glacialis.
Rice (1998) classified right whales in the
Based on their different catch and recovery histories, right whales in the eastern and western North Pacific are considered separate subpopulations with little or no genetic exchange (Brownell et al. 2001).
|Red List Category & Criteria:||Critically Endangered D ver 3.1|
|Assessor(s):||Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N.|
|Reviewer(s):||Taylor, B.L. & Notarbartolo di Sciara, G. (Cetacean Red List Authority)|
Although no estimate of abundance exists for right whales in the eastern North Pacific, the paucity of sightings make it very probable that the mature subpopulation size is below 50 individuals. In addition there is concern about the paucity of sightings of calves.
Prior to the
onset of commercial whaling in the 1830s, right whales were widely distributed
across the North Pacific (Scarff 1986, Clapham et al. 2004, Shelden et al.
2005). In the eastern North Pacific, the waters adjacent to the Aleutian
Islands and much of the Bering Sea below 60oN were major feeding
grounds during spring, summer and autumn, as was virtually the entire
In recent decades, both the southeastern Bering Sea and the western
movements are evident in sighting and catch data from the 20th
century, with a general northward migration into the Gulf of Alaska and
In general, the
majority of eastern North Pacific right whale sightings (historically and in
recent times) have occurred from about 40º N to 60º N. There are historical
records from north of 60º N, but these are rare and many are likely to be
misidentified bowhead whales. Right whales have on rare occasions been recorded
Recent data indicate that while the present range of the remnant eastern subpopulation is likely reduced relative to pre-whaling times, the southeastern Bering Sea and western Gulf of Alaska (south of Kodiak) remain important habitats.
Native:Canada; Mexico; United States
|FAO Marine Fishing Areas:||
Pacific – eastern central; Pacific – northeast
|Range Map:||Click here to open the map viewer and explore range.|
As noted above, right whales in the eastern North Pacific are considered to be separate from those in the west on the basis of distinct catch and recovery histories (Brownell et al. 2001, IWC 2001). The right whale population throughout the North Pacific is only a small fraction of what it was prior to 19th century whaling. A preliminary estimate of 26,500-37,000 animals taken (including struck and lost) throughout the entire North Pacific during the period 1839-1909 was given by Scarff (2001), of which 21,000-30,000 were taken during 1840-49 alone.
In the eastern North Pacific between 1941 and 1964, there were 598 sightings of right whales; in contrast, in the period 1965-1999 there was a total of only 82 sightings in this region (Brownell et al. 2001). The dramatic decrease was due to illegal Soviet catches of 372 whales in the Bering Sea and Gulf of Alaska, mainly in the period 1963-66 (Doroshenko 2000); given the paucity of sightings in subsequent years, this catch total may well have constituted the bulk of the remaining subpopulation. In all, 411 right whales were killed in the eastern North Pacific in the 20th century (Brownell et al. 2001).
The few animals observed in the eastern North Pacific today are often alone and are scattered in their distribution. The only exception is an area of the southeastern Bering Sea where small groups of right whales have been seen in several successive years (LeDuc et al. 2001); in 2004, a recorded group of at least 17 individuals represented the largest sighting since the Soviet catches of the 1960s (Wade et al. 2006). No quantitative estimate of abundance is available, but the paucity of sightings suggests that right whales in the eastern North Pacific number only in the tens (Brownell et al. 2001). Furthermore, the reproductive rate appears to be low: there have been only three records of calves since directed survey effort began in 1998 (Waite et al. 2003, Wade et al. 2006).
|Current Population Trend:||Unknown|
|Habitat and Ecology:||
Little is known about habitat use by eastern
North Pacific right whales. The rarity of coastal records in winter in either
historical or recent times suggests that their breeding grounds may have been
offshore (Clapham et al. 2004). This
is in contrast to southern and North Atlantic right whales, both of which form
inshore breeding concentrations. There is clearly some northward migration in
summer and southward in winter (Clapham et
al. 2004), but the location of the wintering grounds is unknown. The
historical catches show that in summer the population occurred mainly on
feeding grounds in the Bering Sea and
|Movement patterns:||Full Migrant|
Commercial hunting for right whales in the eastern North Pacific was initiated by Europeans and Americans in the 1830s; by about 1900, the subpopulation had been reduced to a fraction of its original abundance, as evidenced by the comparatively low number of 20th century sightings (Brownell et al. 2001). Although legally protected by the IWC since 1946 (and by an earlier agreement in 1935), illegal hunting continued into the 1960s with the Soviet catches of 372 animals in the eastern North Pacific (Doroshenko 2000, Brownell et al. 2001).
There is currently no evidence of human-related mortality or injury, but the very low observer effort and remoteness of the right whale’s habitats probably means that most deaths and injuries pass unrecorded.
The eastern North Pacific subpopulation is subject to anthropogenic threats such as entanglements in fishing gear, disturbance by vessels and other noise, collisions, and possibly petroleum-related and other contaminants.
As compared with the intensively studied North Atlantic right whale, the more offshore and remote distribution of eastern North Pacific right whales may be an advantage in terms of less intensive exposure to human impacts, but the disadvantage is that impacts that do occur are less likely to be detected and their consequences are harder to ascertain and evaluate.
Small populations numbering less than a few
hundred individuals can have a number of interacting effects that accelerate
overall risk (Gilpin and Soule, 1986). Among those effects are
demographic stochasticity, inbreeding depression and density depensation (Allee
effects). Although direct data are lacking for marine mammals at low
density, the expectation is that these threats could be serious because
cetaceans are social animals with low reproductive output.
North Pacific right whales were legally
protected from commercial whaling through international agreements in 1935 and
1946, but this has been fully respected in practice only since the 1970s. A
Recovery Plan has been developed by the US National Marine Fisheries Service,
but to date the only conservation measure undertaken has been the designation
in 2006 of two areas of Critical Habitat (the southeastern Bering Sea and a
small region off eastern
The species is listed in Appendix I of both CITES and CMS.
|Citation:||Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008. Eubalaena japonica (Northeast Pacific subpopulation). The IUCN Red List of Threatened Species 2008: e.T133706A3873095. . Downloaded on 09 October 2015.|
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