Whale Sightings Research Articles

What gets left behind for future generations? Reproduction and the environment in Spey Bay, Scotland

What gets left behind for future generations? Reproduction and the environment in Spey Bay, Scotland

Recent observations of critically endangered North Pacific right whales (Eubalaena japonica) off the west coast of Canada

The eastern North Pacific population of right whale (Eubalaena japonica) is considered to be one of the smallest whale populations in the world and is at serious risk of extirpation. During the past century, there have been only six records of North Pacific right whales off the west coast of Canada. All six were taken by whaling operations, the last in 1951. Two independent and extremely rare sightings of North Pacific right whales were made off the coast of British Columbia, Canada, in 2013. We describe observations made of these two whales and include information on prey and genetic identity for one individual. These sightings represent the first time this species has been confirmed in Canadian waters in 62 years, and likely the only time in the last 15 years that the species has been sighted south of the Kodiak Island area, Alaska, in the eastern North Pacific Ocean. It can be concluded that, although extremely rare, the species has not been extirpated from waters off Canada’s Pacific coast.

Blue whales Balaenoptera musculus in offshore waters of Kenya

Observations of blue whales were made in Kenyan offshore waters during a seismic survey from September 2014 to January 2015. These represent the first live at-sea sightings of blue whales reported from Kenyan waters. All 30 sightings occurred between September and October in waters ranging from 2 990 to 4 705 m depth. It is unknown to which of the three possible subspecies the animals sighted belong. Based on timing and geographical location, they are likely to have been either Antarctic blue whales Balaenoptera musculus intermedia, Madagascar pygmy blue whales B. m. brevicauda or northern Indian Ocean blue whales B. m. indica.

Gray whale sightings in the Canadian Beaufort Sea, September 2014

Gray whales (Eschrichtius robustus) are distributed within the productive neritic and estuarine waters of the North Pacific Ocean, the Bering Sea, and adjacent waters of the Arctic Ocean. They migrate to high-latitude feeding grounds each spring. Their main feeding grounds in the Arctic include the Chirikov Basin, the northeastern Chukchi Sea from Pt. Hope to Cape Lisburne and Pt. Lay to Pt. Barrow, and the northwestern Chukchi Sea along the Chukotka coast. Although sightings are rare in the Canadian Beaufort Sea, we observed three gray whales in two groups in this area in September 2014. A mud plume was observed near one of the whales, suggesting the animal had been feeding. In the Alaskan Beaufort Sea, large-scale monitoring of the distributions of marine mammals has been continuously conducted since 1979; however, there has been less monitoring in the Canadian Beaufort Sea. Therefore, it is necessary to record opportunistic sightings, such as those described here.

Relative abundance of sound scattering organisms in the Northwestern Hawaiian Islands is a driver for some odontocete foragers

Previous studies in the Northwestern Hawaiian Islands (NWHI) focused on shallower communities in and near reefs and did not investigate the organisms living in deeper waters that some apex predators rely on for food, e.g., some odontocetes forage at depths greater than 400 m. To examine the relationship between deep-diving odontocete predators and prey, a Simrad EK60 echosounder operating at 70 kHz collected acoustic abundance throughout the NWHI from May 7 to June 4, 2013. Visual and passive acoustic surveys for marine mammal presence were conducted concurrently with the echosounder. Two broad scattering layers were found, a deep layer from 325 to 670 m and a shallow layer from 0 to 195 m. The highest densities of both deep and shallow scattering organisms were associated with deep slopes of banks and atolls. Beaked and short-finned pilot whale sightings occurred in locations of high scattering density associated with slopes of atolls and banks. It is hypothesized that the high scattering organisms associated with these features are similar to the mesopelagic boundary community found in the Main Hawaiian Islands and support a food web representing the prey of the cetaceans.

Evaluation of Alternatives to Winter Closure of Black Sea Bass Pot Gear: Projected Impacts on Catch and Risk of Entanglement with North Atlantic Right Whales Eubalaena glacialis

AbstractTime–area closures have been widely used in fisheries management to prevent overfishing and reduce the bycatch of protected species. Due to quota overages and concerns about entanglement of federally protected North Atlantic right whales Eubalaena glacialis, the commercial harvest of Black Sea Bass Centropristis striata using pot gear has been prohibited in the southeastern United States in winter since 2009. Following the rebuilding of the Black Sea Bass stock and a change to the start date of the fishing year, the South Atlantic Fishery Management Council (SAFMC) increased the commercial annual catch limit (ACL) and is considering twelve alternatives to the pot gear closure that would revise the timing and/or spatial extent of the closure. Changes to this closure could affect the annual catch of Black Sea Bass and increase the risk of right whale entanglement in pot gear. Using historical fishing effort, landings, and right whale sightings data, we projected Black Sea Bass landings and the relative risk of right whale entanglement for each closure alternative, expressed in relative risk units (RRU). We predict that the ACL would be caught, resulting in an in‐season closure for most of the proposed SAFMC closure alternatives. The relative risk of entanglement, estimated from the spatial and temporal overlap of Black Sea Bass pot gear fishing effort and right whale relative abundance, was lower for some alternatives than for others, and the relative differences between alternatives were consistent among uncertainty scenarios. The SAFMC's preferred alternative is projected to result in a relatively low increase in risk to North Atlantic right whales (3–15 RRU off North Carolina and 1–12 RRU off Florida–South Carolina). This framework demonstrates the use of temporally dynamic spatial overlays in assessing the impacts of time–area closures with multiple objectives.Received April 23, 2015; accepted January 15, 2016

New records of Cuvier’s beaked whales (Ziphius cavirostris)from the Turkish Levantine Sea

Cuvier's beaked whales were sighted once on each of three different surveys over Antalya Canyon, in June and September 2015. Sightings took place in waters between 600 and 1000 m in depth and at 8 km from the closest shore. While the first sighting was positively identified as Cuvier's beaked whale (Ziphius cavirostris (G. Cuvier, 1823)), latter sightings could not be identified to the species level. Nevertheless, noting that latter sightings had a similar spatial and temporal distribution to the first one and that there is an overwhelming difference between the probabilities of sighting Cuvier's beaked whales versus Mesoplodon sp. İn the Mediterranean Sea, all three sightings were assumed to be Cuvier's beaked whales. Group size was recorded as two for the first two sightings and one for the last sighting. We hereby report the most recent Cuvier's beaked whale sightings from the Levantine Basin and the first ones from Antalya Bay, as well as compile the previous sighting and stranding information on beaked whales in the eastern Mediterranean Sea. The current study supports previous modeling results showing the northern region of the Levantine Sea to be of importance to the species distribution in the Mediterranean Sea and we propose that the species is indeed regularly present in the area. However, consistent regional surveys are needed in order to validate these conclusions.

Bucking the trend: genetic analysis reveals high diversity, large population size and low differentiation in a deep ocean cetacean.

Understanding the genetic structure of a population is essential to its conservation and management. We report the level of genetic diversity and determine the population structure of a cryptic deep ocean cetacean, the Gray's beaked whale (Mesoplodon grayi). We analysed 530 bp of mitochondrial control region and 12 microsatellite loci from 94 individuals stranded around New Zealand and Australia. The samples cover a large area of the species distribution (~6000 km) and were collected over a 22-year period. We show high genetic diversity (h=0.933-0.987, π=0.763-0.996% and Rs=4.22-4.37, He=0.624-0.675), and, in contrast to other cetaceans, we found a complete lack of genetic structure in both maternally and biparentally inherited markers. The oceanic habitats around New Zealand are diverse with extremely deep waters, seamounts and submarine canyons that are suitable for Gray's beaked whales and their prey. We propose that the abundance of this rich habitat has promoted genetic homogeneity in this species. Furthermore, it has been suggested that the lack of beaked whale sightings is the result of their low abundance, but this is in contrast to our estimates of female effective population size based on mitochondrial data. In conclusion, the high diversity and lack of genetic structure can be explained by a historically large population size, in combination with no known exploitation, few apparent behavioural barriers and abundant habitat.

The IPY 2007–2008 data legacy – creating open data from IPY publications

Abstract. The International Polar Year (IPY) 2007–2008 was a synchronized effort to simultaneously collect data from polar regions. Being the fourth in a series of IPYs, the demand for interdisciplinarity and new data products was high. However, despite all the research done on land, people, ocean, ice and atmosphere and the large amount of data collected, no central archive or portal was created for IPY data. In order to improve the availability and visibility of IPY data, a concerted effort between PANGAEA – Data Publisher for Earth and Environmental Science, the International Council for Science (ICSU) World Data System (WDS), and the International Council for Scientific and Technical Information (ICSTI) was undertaken to extract data resulting from IPY publications for long-term preservation. Overall, 1380 IPY-related references were collected. Of these, only 450 contained accessible data. All data were extracted, quality checked, annotated with metadata and uploaded to PANGAEA. The 450 articles dealt with a multitude of IPY topics – plankton biomass, water chemistry, ice thickness, whale sightings, Inuit health, alien species introductions by travellers or tundra biomass change, to mention just a few. Both the Arctic and the Antarctic were investigated in the articles, and all realms (land, people, ocean, ice and atmosphere) and a wide range of countries were covered. The data compilation can now be found with the identifier doi:10.1594/PANGAEA.150150, and individual parts can be searched using the PANGAEA search engine (www.pangaea.de) and adding "+project:ipy". With this effort, we hope to improve the visibility, accessibility and long-term storage of IPY data for future research and new data products.

Traditional knowledge and historical and opportunistic sightings of beluga whales, Delphinapterus leucas, in Yakutat Bay, Alaska, 1938-2013

Traditional knowledge and historical and opportunistic sightings of beluga whales, Delphinapterus leucas, in Yakutat Bay, Alaska, 1938-2013

Northeasternmost record of a North Pacific fin whale (Balaenoptera physalus) in the Alaskan Chukchi Sea

Fin whales (Balaenoptera physalus) in the North Pacific consistently range as far north as the Bering Sea. While occasional sightings of fin whales occur north of the Bering Strait, they are rarely documented north of 67°N. However, a recent increase in passive acoustic monitoring has shown that fin whales are more prevalent in the Chukchi Sea than previously thought. During a 2012 field survey in the Alaskan Chukchi Sea, fin whale calls were detected on a DiFAR sonobuoy deployed at 71.575°N, 157.823°W, 50 km off Barrow near the mouth of Barrow Canyon. On August 27, 2012, approximately 30 fin whale downsweep calls were detected over an hour and a half, at bearings of approximately 270–290° from the sonobuoy. Since only one sonobuoy was deployed, in situ localization of the calls was not possible. Post hoc range estimates using a combination of modal dispersion techniques, nonlinear time-domain warping, and geoacoustic inversion resulted in a source range estimate of less than 5 km. This location is approximately 280 and 365 km northeast of the previous closest acoustic detection and confirmed visual sighting of a fin whale, respectively. These results represent the farthest northeast record of fin whale calls in the Alaskan Arctic and illustrate the importance of continued passive acoustic monitoring in a rapidly changing environment.

Oceanographic connectivity between right whale critical habitats in Canada and its influence on whale abundance indices during 1987–2009

The Roseway and Grand Manan basins on the Canadian Atlantic coast are neighboring late-summer critical feeding habitats for endangered North Atlantic right whales. Although in late summer these habitats regularly contain thick aggregations of right whale food – the copepod Calanus spp. – right whales periodically abandon one or both habitats in the same year. The causes of abandonments, their relationship to food supply, and the locations of whales during abandonment periods are unclear. The goals of this study were to explain variation in right whale abundance indices from a habitat perspective, and to determine whether or not oceanographic variation in the habitats influences occupancy. Four indices of whale abundance and habitat occupancy, including sightings per unit effort (SPUE), photographic sightings of known individuals, population size and habitat transition probabilities, were analyzed in relation to unique datasets of Calanus concentration and water mass characteristics in each basin over the period 1987 through 2009. Calanus concentration, water mass sources and various hydrographic properties each varied coherently between basins. Calanus concentration showed an increasing trend over time in each habitat, although a short-lived reduction in Calanus may have caused right whales to abandon Roseway Basin during the mid-1990s. Food supply explained variation in right whale sightings and population size in Roseway Basin, but not in Grand Manan Basin, suggesting that the Grand Manan Basin has important habitat characteristics in addition to food supply. Changes in the distribution of whale abundance indices during years when oceanographic conditions were associated with reduced food supply in the Scotia-Fundy region suggest that other suitable feeding habitats may not have existed during such years and resulted in negative effects on whale health and reproduction.

A hidden getaway for bowhead whales in the Greenland Sea

The critically endangered Spitsbergen stock of bowhead whale (Balaena mysticetus) seems to be increasing. However, research effort has also been increasing confounding a firm conclusion. A systematic aerial survey for walrus (Odobaenus rosmarus), applying distance sampling methodology in part of the Northeast Water Polynya (NEW), revealed a ‘bycatch’ of several observations of bowhead whales, which resulted in an estimated abundance of 102 (95 % CI 32–329) individuals. This is the largest abundance of bowhead whales reported from the Greenland Sea since the days of whaling in the sixteenth to seventeenth centuries. The NEW was inaccessible to vessels during the whaling period because of heavy pack ice, and it is only recently that researchers have visited this area; thus only a few sightings of bowhead whales within the NEW exist prior to the survey in 2009. The NEW may nevertheless be one of the most important summering grounds for the Spitsbergen stock, and the whales may benefit from advection of calanoid copepods from the productive deep basins along the coast of Svalbard east of the NEW. This discovery provides renewed hope for the Spitsbergen stock of bowhead whales that until now has shown only inconclusive signs of recovery despite more than 100 years of protection from whaling.

Whales and waves: Humpback whale foraging response and the shoaling of internal waves at Stellwagen Bank

AbstractWe tested the hypothesis that humpback whales aggregate at the southern flank of Stellwagen Bank (SB) in response to internal waves (IWs) generated semidiurnally at Race Point (RP) channel because of the presence of their preferred prey, planktivorous fish, which in turn respond to zooplankton concentrated by the predictable IWs. Analysis of synthetic aperture radar (SAR) images indicates that RP IWs approach the southern flank of SB frequently (∼62% of the images). Published reports of whale sighting data and archived SAR images point to a coarse spatial coincidence between whales and Race Point IWs at SB's southern flank. The responses of whales to IWs were evaluated via sightings and behavior of humpback whales, and IWs were observed in situ by acoustic backscatter and temperature measurements. Modeling of IWs complemented the observations, and results indicate a change of ∼0.4 m/s in current velocity, and ∼1.5 Pa in dynamic pressure near the bottom, which may be sufficient for bottom fish to detect the IWs. However, fish were rare in our acoustic observations, and fish response to the IWs could not be evaluated. RP IWs do not represent the leading edge of the internal tide, and they may have less mass‐transport potential than typical coastal IWs. There was large interannual variability in whale sightings at SB's southern flank, with decreases in both numbers of sightings and proportion of sightings where feeding was observed from 2008 to 2013. Coincidence of whales and IWs was inconsistent, and results do not support the hypothesis.

Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100.

Arctic animals face dramatic habitat alteration due to ongoing climate change. Understanding how such species have responded to past glacial cycles can help us forecast their response to today's changing climate. Gray whales are among those marine species likely to be strongly affected by Arctic climate change, but a thorough analysis of past climate impacts on this species has been complicated by lack of information about an extinct population in the Atlantic. While little is known about the history of Atlantic gray whales or their relationship to the extant Pacific population, the extirpation of the Atlantic population during historical times has been attributed to whaling. We used a combination of ancient and modern DNA, radiocarbon dating and predictive habitat modelling to better understand the distribution of gray whales during the Pleistocene and Holocene. Our results reveal that dispersal between the Pacific and Atlantic was climate dependent and occurred both during the Pleistocene prior to the last glacial period and the early Holocene immediately following the opening of the Bering Strait. Genetic diversity in the Atlantic declined over an extended interval that predates the period of intensive commercial whaling, indicating this decline may have been precipitated by Holocene climate or other ecological causes. These first genetic data for Atlantic gray whales, particularly when combined with predictive habitat models for the year 2100, suggest that two recent sightings of gray whales in the Atlantic may represent the beginning of the expansion of this species' habitat beyond its currently realized range.

Viewing Moby-Dick through the Lens of the Charles W. Morgan

Viewing Moby-Dick through the Lens of the Charles W. Morgan Peter Norberg I was fortunate to be on the second leg of the 38th Voyage of the Charles W. Morgan, an outbound reach from Newport, Rhode Island, to Vineyard Haven, Massachusetts. I chose this leg of the voyage because it would overlap the course Melville sailed aboard the Acushnet and then follow in the imaginary wake of the packet schooner, Moss, which carried Ishmael and Queequeg from New Bedford to Nantucket. When the Morgan crossed the mouth of Buzzard’s Bay and sailed up Vineyard Sound, it would traverse both the actual and the imaginary routes Melville traveled and perhaps provide an opportunity, in the words of Nathaniel Hawthorne in “The Custom-House,” for “each [to] imbue itself with the nature of the other” (Hawthorne, Library of America Collected Novels, 149). To what extent would the historically accurate workings of a whaleship help me better understand the aesthetics of an epic novel that was inspired by the business of whaling? To answer this question, I planned to stage readings of passages from Moby-Dick that could be associated with material aspects of the ship and to capture video that could be embedded in an online module designed to supplement a range of courses in which Moby-Dick is taught at my institution, and perhaps beyond. My initial goals were modest: to create video illustrations for chapters like “The Line” or “The Try-Works,” while having other voyagers and crew members read relevant passages from these chapters in real time. This was primarily an experiment in pedagogy designed to discover the extent to which the Morgan could be used as a material source for understanding Melville’s novel. I intended to treat the Morgan as a source for Moby-Dick, but I learned that Melville’s novel is itself a potent source for scholars, informing and inspiring their work across a range of disciplines. When I described my project to the other eight voyagers onboard, I was surprised to learn that five of them had brought along their personal copies of Moby-Dick. More surprising still, each person had a favorite chapter that referenced source elements related to their own scholarly interests. The cetology chapters embody what I call an aesthetic of curiosity: these chapters mark moments when a range of intellectual pursuits intersect and inform one another, fueling the sort of critical, speculative thinking that leads to innovation. [End Page 120] Click for larger view View full resolution Peter Norberg at the wheel of the Charles W. Morgan en route to the island of Martha’s Vineyard. Photo courtesy of Peter Norberg. For example, Jason Smith, a historian interested in how cartography was used to define the ocean in commercial and strategic terms, was excited to read from chapter 44, “The Chart.” With a sea chest to serve as desk, and a variety of props including navigational charts “borrowed” from the Captain’s quarters, a sextant and compass, and a copy of Nathaniel Bowditch’s American Practical Navigator, Jason read up through the footnote describing the chart prepared by Lieutenant Matthew Fontaine Maury that recorded sightings of right and sperm whales. Joe Forbrich, a playwright and actor, gave an intense reading of the section of chapter 45, “The Affadavit,” that references Owen Chase’s Narrative of the Shipwreck of the Whale-Ship Essex. Joe’s most recent work, a play that dramatically brings to life Chase’s story of survival, was due to premiere the following night at the Martha’s Vineyard Playhouse, and he grabbed my battered copy of Moby-Dick eager to find the passage that showed his and Melville’s common inspiration: “I have seen Owen Chase, who was chief mate of the Essex at the time of the tragedy; I have read his plain and faithful narrative; I have conversed with his son; and all this within a few miles of the scene of the catastrophe” (NN Moby-Dick 206). [End Page 121] Jamie Jones, a cultural critic interested in the history of whaling, read movingly from chapter 87, “The Grand Armada.” Jamie’s research focuses on the cultural afterlife of the whaling industry, and...

Humpback Whale (Megaptera novaeangliae) Distribution On Stellwagen Bank (New England, MA, USA)

Humpback whales (Megaptera novaeangliae) are found in all oceans and complete one of the longest migrations of any mammal. Their movements in their feeding ground areas are difficult to track and therefore are largely unknown. This study used data from Whale and Dolphin Conservation (WDC) and Ocean Biogeographic Information System (OBIS) to map the movements of humpback whales for the year 2011 as well as between the decades of the 1980s, 1990s, 2000s, and for 20102012. GIS maps of humpback whale sightings from these data sets showed patterns of seasonal movement as well as high use areas. The distributions of the humpbacks in all four decades showed two concentrated areas where the whales were sighted more often: north of Cape Cod, in the Stellwagen Bank National Marine Sanctuary and to the southeast of Cape Cod. The percentages of humpbacks over different types of benthic substrate were also calculated and statistically analyzed using a Chi-square. The relationship between the number of sightings and the type of substrate was determined to be significant for the spring and summer months. The whales were more likely to be found over sandy substrate in the spring and summer. This is most likely because the schooling fish that they eat are most likely to be in those areas. However, this relationship did not hold for the fall months and this is likely because their prey has moved over a different substrate. These results agreed with those of NOAA’s study of the same area.

Effect of seismic operations on cetaceans sightings off-shore Akwa Ibom State, south-south, Nigeria

The possible behavioral and physical problems involving cetaceans and marine seismic surveys have attracted the interest and concern of several authors. However, studies on cetaceans frequenting Nigerian waters have not been detailed in literature. This research work is appropriately driven by these requirements. Opportunistic data was collected on board six different marine vessels belonging to ExxonMobil. Data collected were analyzed using descriptive statistics, t-test and ANOVA at p=0.05. A total of 8,327 hours 36 minutes observation effort was accomplished during twenty-six months, representing almost 800 km2 of coverage. Two hundred and eighty-three (283) sightings were recorded comprising of 189 (66.78%) sightings of whales and 94 (33.22%) sightings of dolphins. Four species of cetaceans were identified, bottlenose dolphins (Tursiops truncatus) were the most abundant followed by pantropical spotted dolphins (Stenella attenuata). These two species occurred throughout the sampling months, while the predominant whales specie were the humpback whale (Megaptera novaeangliae) and killer whales (Orcinus orca) which seem to be present in just a part of the year. Whales were sighted more when the guns were active. Conversely, less of the dolphins were sighted while the guns were active. There were significant differences (P=0.05) regarding the air-gun operational state between the number of whales and dolphins sightings. The result suggests that swimming behavior was dependent of air-gun operational state.Keywords: Cetaceans, seismic survey, Sightings, Akwa Ibom state, south-south Nigeria.

A longitudinal study of humpback whales in Irish waters

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.

North Pacific right whales (Eubalaena japonica) recorded in the northeastern Pacific Ocean in 2013

Notes MARINE MAMMAL SCIENCE, **(*): ***–*** (*** 2014) © 2014 The Authors. Marine Mammal Science published by Wiley Periodicals, Inc. on behalf of Society for Marine Mammalogy This is an open access article under the terms of the Creative Commons Attribution- NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. DOI: 10.1111/mms.12189 North Pacific right whales (Eubalaena japonica) recorded in the northeastern Pacific Ocean in 2013 A NA S IROVI C , 1 S ARAH C. J OHNSON , L AUREN K. R OCHE , L EAH M. V ARGA , S EAN M. W IGGINS and J OHN A. H ILDEBRAND , Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive MC 0205, La Jolla, California 92093-0205, U.S.A. The North Pacific right whale (Eubalaena japonica) is among the most critically endangered marine mammals in the world (Brownell et al. 2001). Its population was drastically reduced by 19th and 20th century whaling and its recovery was addition- ally slowed by illegal Soviet whaling that occurred during the 1960s (Clapham et al. 2004, Ivashchenko and Clapham 2012). With a severe decrease in the population also came a restriction in range, from extensive distribution across the North Pacific, to a constricted presence of two different populations, one in the Sea of Okhotsk and along the Western Pacific, and the other in the eastern Bering Sea (Scarff 1986, Clap- ham et al. 2004, Josephson et al. 2008). The abundance estimates for the eastern pop- ulation are around 30 animals (Wade et al. 2006, 2011b; Marques et al. 2011), while the western population is considered to be larger with current estimates of probably no more than 300 animals (Brownell et al. 2001). Most baleen whales undertake seasonal migrations, spending summers feeding in high latitude, productive areas and winters in warmer, lower latitude breeding grounds (Kellogg 1929). North Pacific right whales spend their summers in the Ber- ing Sea and, to a lesser extent, the Gulf of Alaska, the Aleutian archipelago, and off Kodiak (Scarff 1986, Brownell et al. 2001, Clapham et al. 2004, Mellinger et al. 2004, Shelden et al. 2005, Wade et al. 2011a). Most current research effort has been focused within the area in the Southeastern Bering Sea where North Pacific right whales have been sighted most frequently (Wade et al. 2006, Munger et al. 2008). Over the years, however, a small number of sightings of single right whales have been Corresponding author (e-mail: asirovic@ucsd.edu).