Abstracts of Scientific Publications on North Pacific Right Whales (Eubalaena japonica)
(updated: September 12, 2012)
Ivashchenko, Y.V. & Clapham, P.J. 2012. Soviet catches of bowhead (Balaena mysticetus)
and right whales (Eubalaena japonica) in the North Pacific and Okhotsk Sea.
Endangered Species Research 18: 201-217.
Both bowhead Balaena mysticetus and North Pacific (NP) right whales Eubalaena japonica were reduced to low levels by historical whaling. Despite their protected status, it is known that the USSR illegally killed both species in the NP and Okhotsk Sea (OS). Here, we provide revised Soviet catch totals, as well as other new information on the distribution and other details of these catches. Right whale catches were made from 1962 to 1968 in the eastern NP and in 1967 and 1968 in the OS. Our best estimate of total right whale catches is 661, consisting of 529 for the eastern NP (compared to the previously published figure of 372) and 152 for the OS (cf. a previous figure of 136). Catches were distributed in the Bering Sea (BS, 115), eastern Aleutian Islands (28), Gulf of Alaska (GOA, 366), OS (132), and other areas (20). Detailed information on catches of 112 right whales taken in May/June 1963 shows a broad distribution in offshore waters of the GOA, consistent with 19th century historical whaling records. Other major areas in which right whales were caught include south of Kodiak Island, western Bristol Bay (southeastern BS), and the central OS off eastern Sakhalin Island. The best estimate of bowhead whale catches in the OS in 1967 and 1968 is 145 animals, although this is contingent upon certain assumptions regarding species identity. Of these, 79 were killed in the Shantar Islands region and 66 in Shelikhov Bay. The catches of both species primarily involved large mature animals, thus greatly inhibiting recovery of the populations concerned.
Wade, P. R., A. De Robertis, K. Hough, R. Booth, A. Kennedy, R. LeDuc, L. Munger, J. Napp, K. E. W. Shelden, S. Rankin, O. Vasquez, and C. Wilson. 2011. Rare detections of North Pacific right whales in the Gulf of Alaska, with observations of their potential prey. Endang. Species Res. 13:99-109. (.pdf, 2 MB).
The North Pacific right whale Eubalaena japonica was heavily exploited throughout the Gulf of Alaska by both historical whaling and 1960s illegal Soviet catches. It is now extremely rare in this region (2 sightings between 1966 and 2003 and passive acoustic detections on 6 days out of 80 months of recordings at 7 locations). From 2004 to 2006, 4 sightings of right whales occurred in the Barnabus Trough region on Albatross Bank, south of Kodiak Island, Alaska, USA. Sightings of right whales occurred at locations within the trough with the highest density of zooplankton, as measured by active acoustic backscatter. Net trawls through a high-density demersal layer (~150 to 175 m) revealed large numbers of euphausiids and oil-rich C5-stage copepods. Photo-identification and genotyping of 2 whales failed to reveal a match to Bering Sea right whales. Fecal hormone metabolite analysis from 1 whale estimated levels consistent with an immature male, indicating either recent reproduction in the Gulf of Alaska or movements between the Bering Sea and the Gulf of Alaska. Large numbers of historic catches of right whales occurred in pelagic waters of the Gulf of Alaska, but there have been few recent detections in deep water. Given that there is no other location in the Gulf of Alaska where right whales have been repeatedly seen post-exploitation, the Barnabus Trough/Albatross Bank area represents important habitat for the relict population of North Pacific right whales in the Gulf of Alaska, and a portion of this area was designated as critical habitat under the US Endangered Species Act in 2006.
Munger, L. M., Wiggins, S. M. W., Moore, S. E., and J. A. Hildebrand. 2008. North Pacific right whale (Eubalaena japonica) seasonal and diel calling patterns from long-term acoustic recordings in the southeastern Bering Sea, 2000–2006. Marine Mammal Science: Volume 24 Issue 4, Pages 795 - 814.
We assessed North Pacific right whale (Eubalaena japonica) seasonal and daily calling patterns in the southeastern Bering Sea (SEBS) using long-term hydrophone recordings from October 2000 through January 2006. We detected right whale calls on the SEBS middle shelf (<100 m depth) as early as May, intermittently throughout summer and fall, and as late as December. Calls also were detected on one day in June 2005 on the SEBS slope (>1,000 m), but were not detected near Kodiak Island from April to August 2003. In months with calls, detections occurred on more days in July–October (≥6 d/mo), than from May to June or November to December (≤3 d/mo). Calls were clustered in time and were usually detected on 1–3 consecutive days with a median interval of 6.5 d for calls >1 d apart. Hourly calling rates were significantly higher at night than during the day. These data indicate that right whales occur in the SEBS later in the year than previously known, intermittently pass through the middle-shelf study region, and usually remain there no longer than a few days. Right whale habitat use in the SEBS may intensify in mid-summer through early fall based on higher monthly and daily call detection rates.
Josephson, E, T. D Smith and R. R Reeves. 2008. Historical distribution of right whales in the North Pacific. Fish and FisheriesVolume 9 Issue 2:155-168.
Fisheries records provide some of the only information on pre-fishing distribution and abundance for species that were depleted before the advent of modern scientific investigations. This paper interprets records of the early history of whaling for North Pacific right whales (Eubalaena pacifica). The current population occupies only a fraction of its historical range. Historical distributions of several whale species have been inferred from charts prepared by Matthew Fontaine Maury in the early 1850s and Charles Haskins Townsend in the 1930s based on data from American whalers' logbooks. In the North Pacific, Maury's chart has been interpreted to show that right whales occurred continuously across the entire basin. However, we find plotting errors when we compare the North Pacific chart to the corresponding data worksheets prepared for Maury (the 'Maury Abstracts') and the chart appears to have misled historians and biologists. Although these charts and those in the North Atlantic are wrong, the Maury Abstracts themselves appear largely consistent with the original whaler logbooks. Our analysis shows that right whales were likely not distributed continuously across the North Pacific, but instead had a pronounced longitudinally bimodal distribution and were encountered infrequently in the central-northern North Pacific. This work shows how valuable information can be obtained by examining original source material. The American whaling logbooks are extensive and have been largely overlooked in studies of whale populations.
Wade, P., Heide-Jørgensen, M.P., Shelden, K, Barlow, J., Carretta, J., Durban, J., LeDuc, R., Munger, L,, Rankin, S., Sauter, A., Stinchcomb, C. 2006. Acoustic detection and satellite-tracking leads to discovery of rare concentration of endangered North Pacific right whales. Biol. Lett. 2, 417-419.
The North Pacific right whale, Eubalaena japonica, is one of the most endangered species of whale in the world. On 10 August 2004, two right whales were located in the Bering Sea using headings to right whale calls provided by directional sonobuoys. A satellite-monitored radio tag attached to one of these whales functioned for 40 days. Over the 40-day period, this whale moved throughout a large part of the southeast Bering Sea shelf, including areas of the outershelf where right whales have not been seen in decades. In September, multiple right whales were acoustically located and subsequently sighted by another survey vessel approaching a near-real-time position from the tag. An analysis of photographs confirmed at least 17 individual whales (not including the tagged whales). Genetic analysis of biopsy samples identified 17 individuals: 10 males and 7 females. The discovery of seven females was significant, as only one female had been identified in the past. Genetics also confirmed the presence of at least two calves. Although the future of this population is highly uncertain, the discovery of additional females and calves gives some hope that this most critically endangered of all whale populations may still possess the capacity to recover.
Sheldon, K.E., S E. Moore, J. M. Waite, P. R. Wade and D. J. Rugh. 2005. Historic and current habitat use by North Pacific right whales Eubalaena japonica in the Bering Sea and Gulf of Alaska. Mammal Rev.Volume 35, No. 2, 129–155.
1.To help define areas and ecological parameters critical to the survival and recovery of the remnant population of North Pacific right whales, habitat use was investigated by examining all available sighting and catch records in the south-eastern Bering Sea (SEBS) and Gulf of Alaska (GOA) over the past two centuries.
2. Based on re-analyses of commercial whaling records, search effort, and resultant catches and sightings, waters of the: (i) SEBS slope and shelf, (ii) eastern Aleutian Islands and (iii) GOA slope and abyssal plain were important habitat for North Pacific right whales through the late 1960s.
3. Since 1980, the only area where right whales have been seen consistently is on the SEBS middle shelf. However, acoustic detections and single sightings have been reported in all other regions except the SEBS slope and oceanic GOA (areas where little, if any, acoustic and visual effort has occurred).
4. Sightings since 1979 were in waters <200 m deep which may simply reflect the paucity of search effort elsewhere. From the commercial whaling era to the late 1960s, right whales were commonly seen in waters >2000 m deep, indicating that their distribution is not restricted to shallow continental shelves.
5. North Pacific right whale sightings through the centuries have been associated with a variety of oceanic features, and there is little in common in the bathymetry of these regions. These whales appear to have a greater pelagic distribution than that observed in the North Atlantic, which may be related to the availability of larger copepods across the SEBS and GOA.
Munger, L., D.K. Mellinger, S.M. Wiggins, S.E. Moore, and J.A. Hildebrand. 2005. Performance of spectrogram correlation in detecting right whale calls in long-term recordings from the Bering Sea. Canadian Acoustics 33 (2): 25-34.
Mellinger, D.K., K. M. Stafford, S. E. Moore, L. Munger, and C. G. Fox. 2004. Detection of North Pacific right whale (Eubalaena japonica) calls in the Gulf of Alaska Marine Mammal Science 20:872-879.
The eastern stock of North Pacific right whales is now one of the rarest cetaceans in U.S. waters and one of the most endangered in the world, with only two verified sightings from the Gulf of Alaska in recent decades. An acoustic survey was conducted using autonomous hydrophones from May 2000 to July 2001 at seven sites in the Gulf.
Recordings were analyzed using automatic call detection software configured for right whale 'up' calls, with manual verification of detected sounds and manual scanning of time periods surrounding the detected calls. On five separate days between 7 Aug and 10 Sep 2000,
71 right whale calls were found from the deep-water site at 53 N 157 W. These are in addition to 10 previously found from near Kodiak Island at 57 N 152 W on 6 Sep 2000. These results show that right whales occurred in the Gulf of Alaska in 2000, and that acoustic monitoring coupled with automatic call recognition techniques can provide information on the occurrence of rare cetaceans.
Clapham, P.J., Good, C., Quinn, S.E., Reeves, R.R., Scarff, J.E. and Brownell, R.L. Jr. 2004. Distribution of North Pacific right whales (Eubalaena japonica) as shown by 19th and 20th century whaling catch and sighting records. J. Cetacean Res. Manage. 6(1):1-6.
North Pacific right whales (Eubalaena japonica) were extensively exploited in the 19th century, and their recovery was further retarded (severely so in the eastern population) by illegal Soviet catches in the period, primarily in the 1960's. Here, we provide monthly plots of right whale sightings and catches from both the 19th and 20th centuries, using data summarized by Scarff (1991, from the whale charts of Matthew Fontaine Maury) and Brownell et al. (2001), respectively. Right whales had an extensive offshore distribution in the 19th century, and were common in areas (such as the Gulf of Alaska and Sea of Japan) where few or no right whales occur today. Seasonal movements of right whales are apparent in the data, although to some extent these reflect survey and whaling effort. That said, these seasonal movements indicate a general northward migration in spring from lower latitudes, and major concentrations above 40o N in summer. Sightings diminished and occurred further south in autumn, and very few animals were recorded anywhere in winter. These north-south migratory movements support the idea of two largely discrete populations of right whales in the eastern and western North Pacific. Overall, these analyses confirm that the size and range of the right whale population is now considerably diminished in the North Pacific relative to the situation during the peak period of whaling for this species in the 19th century. New surveys are urgently required to establish the present distribution of this species for management; existing data suggest that the Bering Sea, the Gulf of Alaska, the Okhotsk Sea, the Kuril Islands and the coast of Kamchatka are the areas with the greatest likelihood of finding right whales today.
Brownell, R.L. Jr., Clapham, P.J., Miyashita, T., and Kasuya, T. . 2001. Conservation status of North Pacific right whales. J. Cetacean Res. Manage. (special issue) 2:269-286.
The North Pacific right whale (Eubalaena japonica) is the most endangered of all great whales, having been subject to intensive commercial whaling in the 19th century. All available 20th century records of this species in the North Pacific were reviewed. There has been a total of 1,965 recorded sightings since 1900; of these 988 came from the western North Pacific, 693 from the eastern North Pacific and 284 had no location specified. Thirteen strandings (all but one from the western North Pacific) were recorded. Known catches for commerical or scientific purposes totaled 742 (331 in the western North Pacific, 411 in the eastern North Pacific). Most of the reported Soviet "sightings" in the eastern North Pacific were actually catches, as may be the case for Soviet sightings in the Okhotsk Sea. In addition, the impact of known Soviet illegal catches in the Okhotsk Sea may be reflected in an apparent decline in sightings after the 1960s (although this may be partly explained by low observer effort). Overall, the data support the hypothesis that at least two stocks of right whales exist in the North Pacific. Any recovery in the western North Pacific population was compromised by the Soviet catches in the Okhotsk region, although recent sightings suggest that this population is still large enough to sustain reproduction. By contrast, Soviet catches in the now-smaller eastern North Pacific population have severely reduced its prospects for recovery. Although the prognosis for this population is poor, a long-term monitoring programme is required to better understand its conservation status and to determine whether it may be affected by human-related problems that would require mitigation.
Scarff, J.E. 2001. Preliminary estimates of whaling-induced mortality in the 19th century Pacific northern right whale (Eubalaena glacialis) fishery, adjusting for struck-but-lost whales and non-American whaling. J. Cetacean Res. Manage. (Special Issue 2): 261-268.
This study develops preliminary estimates of total whaling-induced mortality of northern right whales in the 19th century North Pacific pelagic whale fishery. Best's (1987) study of American whaling returns resulted in estimates of the total American catch of 14,480 and 15,374 northern right whales during the period 1839-1909. The present study offers adjustment factors to estimate total mortality from these catch data. Quantitative data from 14 pelagic expeditions of northern right whales in the North Pacific from 1838-1860 and additional anecdotal information about struck-but-lost animals is reviewed. On 12 voyages, 327 northern right whales were struck with harpoons, but only 133 landed. Adjusted for the subsequent recovery of struck whales, this implies a ratio of 2.43 whales struck for each whale eventually secured and flensed by whaleships. Data from four voyages show that of 148 northern right whales struck with harpoons, 14 sank before they could be processed. From a sample of five voyages, 80 northern right whales were landed and 31 carcasses sank without being secured. During the height of pelagic whaling in the North Pacific, approximately 10% of the fleet was non-American, primarily French. Adjusting recorded catch estimates for struck-but-lost mortality and non-American whaling yields preliminary estimates of total mortality in this fishery in the range of 26,500-37,000 animals during the period 1839-1909. In the single decade of 1840-49, between 21,000-30,000 northern right whales may have been killed in the North Pacific, Sea of Okhotsk and Bering Sea, representing about 80% of the northern right whales killed in this region during the period 1839-1909.
LeDuc, R.G.d, Perryman, W.L., Gilpatrick,, J.W. Jr., Hyde, J., Stinchcomb, C., Carretta, J.V. and Brownell Jr, R.L. 2001. A note on recent surveys for right whales in the southeastern Bering Sea. J. Cetacean Res. Manage. (special issue) 2:287-289.
Research vessel and serial platforms were used between 1997 and 2000 to collect genetic and photographic data from small population of right whales that summers in the southeastern Bering Sea. Totals of 11 and six unique individuals were identified using photographic and genetic methods, respectively. Single matches between years occurred using both methods, and all genetic samples turned out to be from male whales. Long-term research is needed to estimate the size of this population and to determine what threats the whales may be facing.
H. C. Rosenbaum, R. L. Brownwell Jr, M. W. Brown, C. Schaeff, V. Portway, B. N. White, S. Malik, L. A. Pastene, N. J. Patenaude, C. S. Baker, M. Goto, P. B. Best, P. J. Clapham, P. Hamilton, M. Moore, R. Payne, V. Rowntree, C. T. Tynan, J. L. Bannister & R. DeSalle. 2000. World-wide genetic differentiation of Eubalaena: questioning the number of right whale species. Molecular Ecology 9 (11):1793-1802.
Few studies have examined systematic relationships of right whales (Eubalaena spp.) since the original species descriptions, even though they are one of the most endangered large whales. Little morphological evidence exists to support the current species designations for Eubalaena glacialis in the northern hemisphere and E. australis in the southern hemisphere. Differences in migratory behaviour or antitropical distribution between right whales in each hemisphere are considered a barrier to gene flow and maintain the current species distinctions and geographical populations. However, these distinctions between populations have remained controversial and no study has included an analysis of all right whales from the three major ocean basins. To address issues of genetic differentiation and relationships among right whales, we have compiled a database of mito-chondrial DNA control region sequences from right whales representing populations in all three ocean basins that consist of: western North Atlantic E. glacialis, multiple geographically distributed populations of E. australis and the first molecular analysis of historical and recent samples of E. glacialis from the western and eastern North Pacific Ocean. Diagnostic characters, as well as phylogenetic and phylogeographic analyses, support the possibility that three distinct maternal lineages exist in right whales, with North Pacific E. glacialis being more closely related to E. australis than to North Atlantic E. glacialis. Our genetic results provide unequivocal character support for the two usually recognized species and a third distinct genetic lineage in the North Pacific under the Phylogenetic Species Concept, as well as levels of genetic diversity among right whales world-wide.
Scarff, J.E. 1991. Historic distribution and abundance of the right whale (Eubalaena glacialis) in the North Pacific, Bering Sea, Sea of Okhotsk and Sea of Japan from the Maury Whale Charts. Rep. Intl Whal. Commn 41:467-489.
This study tabulates approximately 8,000 sightings of right whales (Eubalaena glacialis) by American pelagic whalers made during approximately 47,000 searching days between 1835 and 1852 in the North Pacific, Bering Sea, Sea of Okhotsk and Sea of Japan reflected in the 1852 Maury Series F Whale Charts Numbers 1 and 2. The data are presented as indices of abundance and number of searching days by 5° of latitude and longitude by month.
The data show that during the 1840s, right whales were abundant in the Gulf of Alaska, southeastern Bering Sea, along the Aleutian Islands, along the Pacific and Sea of Okhotsk coasts of Kamchatka and in the Sea of Japan. The charts also show high indices of abundance of right whales in spring, summer and autumn in the mid-Pacific, although with small searching effort. In many areas, whalers found right whales on 50% or more of the searching days, and in some areas such as the coasts of southern Kamchatka (50-55°N, 155-160°E) in August, whalers reported seeing right whales on over 90% of the searching days (110 out of 120). In the Gulf of Alaska, right whales were seen on 40-60% of the searching days on most sectors, and the samples of searching days (200-500+ days/sector) are sufficiently large to minimize the likelihood that these concentrations were atypical.
The indices of abundance reported here are comiparable to, although higher than, indices derived from Maury's charts for right whales off South Africa, and considerably higher than indices of sperm whales in the North Pacific. The historic indices of abundance and distribution are contrasted to the paucity and distribution of recent sightings.
The data support the conclusion that right whales may have been considerably more common in the North Pacific than previously thought, and consequently their current population size represents an even greater level of depletion. Given the very low level of recent sightings, the species should remain completely protected. Suggestions for further research and management are provided.
Scarff, J.E. 1986. Historic and present distribution of the right whale (Eubalaena glacialis) in the Eastern North Pacific South of 50° North and East of 180° West. Rep. Intl Whal. Commn (Special Issue 10): 43-63.
This paper is a review and analysis of all records of right whales (Eubalaena glacialis) in the North Pacific south of 50°N and east of 180°W. The location and season of 786 records from Maury's (1852 et seq. chart of sightings by early 19th-century whaling ships are described. The sightings and catch of right whales by both the shore-based and pelagic whalers during the 19th and 20th centuries are reviewed along with the available information on whaling effort. Between 1855 and 1900 there were 14 sightings of at least 19 whales along the California coast. Between 1900 and 1982 there were 9 reliable records from the coast of California, 1 from Baja California, 5 from te coast of Washington, 1 from Hawaii, and 12 from mid-ocean. Between 1920 and 1930 a minimum of 123 right whales was takin in the North Pacific. Between 1931 and 1982, another 101 right whales were killed. The searhcing effort for whales in the study area is described for the period 1950-82 and the records analyzed in the context of that searching effort. There are no published records which indicate any calving grounds historically or presently for right whales in the eastern North Pacific. It is hypothesized that right whales that summer in the eastern North Pacific mate, calve, and overwinter in the mid-Pacific or in the western North Pacific. Ecological factors which maight be affecting population recovery are reviewed. The data in this study suggest that the population in the eastern North Pacific is still very small. There is no evidence of population recovery.
Scarff, J.E. 1986. Occurrence of the barnacles Coronula diadema, C. reginae and Cetopirus complanatus (Cirripedia) on right whales. Sci. Rep. Whales Res. Inst. 37:129-153.
On 20 March 1982, a right whale (Eubalaena glacialis) was observed off Half Moon Bay, California (37°30'N, 122°03'W). Approximately 300 coronuline barnacles were observed on the whale. By analyzing photographs of the whale, we identified the barnacles as being Coronula diadema and C. reginae, although the possible occurence of Cetopirus complanatus can not be eliminated. It is hypothesized that the right whale acquired the barnacles during association with a humpback whale (Megaptera novaeangliae), although the barnacles could have been acquired from one of several othe whale species. A review of the literature yielded 22 previous reports of coronuline barnacles on right whales, 10 of Coronula spp., 4 of Cetopirus complanatus, and 8 of unspecified barnacles. Most of these early reports appear to be descriptions of not barnacles but instead the right whale's callosities or whale lice (Cyamus spp.). However, two prior records of Coronula diadema and and two records of Cetopirus complanatus are well documented. A summary of known cetacean host-coronuline barnacle associations is included.