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Despite considerable research on the bowhead whale (Balaena mysticetus) in Alaskan waters, relatively little has been conducted in the northern Bering Sea. To help fill this gap, we documented traditional knowledge of bowhead whales held by Yupik whalers of St. Lawrence Island, Alaska. Results include descriptions of the seasonal movements, distribution, and abundance of bowheads near St. Lawrence Island. The bowhead population appears to be increasing, as is the number of young whales seen. Changing environmental conditions are influencing distribution, leading to a somewhat earlier spring migration and a greater presence of whales near the island in winter. Hunters describe two bowhead migration paths near the island. It is unknown whether these two paths are used by two genetically different groups of whales, or whether the animals are simply responding differently to oceanographic conditions or geography. Our findings are consistent with studies of this bowhead population conducted elsewhere and suggest that additional research is needed to determine possible migratory (or genetic) differences between the two migrations of whales seen at St. Lawrence Island. [ABSTRACT FROM AUTHOR]

An immature female bowhead whale (Balaena mysticetus) was discovered stranded dead at Witless Bay Point, just south of Mobile Point (47°14′ 68.00″N, 52°47′90.00″W) on the southern shore of the Avalon Peninsula of the island of Newfoundland (Newfoundland and Labrador, Canada) on 15 April 2005. This is the second bowhead found stranded dead in Newfoundland in seven years. The first, also an immature female, was discovered in a fjord in northeastern Newfoundland near Rattling Brook (49°40′ N, 56°10′ W) in October 1998. These animals represent the only bowhead whales known to have been sighted, alive or stranded dead, in waters around the island of Newfoundland. Some possible causes of the death of this most recent animal are discussed, including chronic inflammation of the vertebrae and the associated locomotive difficulties. [ABSTRACT FROM AUTHOR]

Brandon, J. R., Breiwick, J. M., Punt, A. E., and Wade, P. R. 2007. Constructing a coherent joint prior while respecting biological realism: application to marine mammal stock assessments. – ICES Journal of Marine Science, 64: 1085–1100. Bayesian estimation methods, employing the Sampling–Importance–Resampling algorithm, are currently used to perform stock assessments for several stocks of marine mammals, including the Bering–Chukchi–Beaufort Seas stock of bowhead whales (Balaena mysticetus) and walrus (Odobenus rosmarus rosmarus) off Greenland. However, owing to the functional relationships among parameters in deterministic age-structured population dynamics models, placing explicit priors on each life history parameter in addition to the population growth rate parameter results in an incoherent joint prior distribution (i.e. two different priors on the estimated parameters). One solution to constructing a coherent joint prior is to solve for juvenile survival analytically, using values generated from the prior distributions for the remaining parameters. However, certain combinations of model parameter values result in values for juvenile survival that are larger than adult survival, which is biologically implausible. Therefore, to respect biological realism, certain parameter values must be rejected for some or all the remaining parameters. This study investigates several alternative resampling schemes for obtaining a realistic joint prior distribution, given the constraint on survival rates. The sensitivity of assessment results is investigated for data-rich (bowhead) and data-poor (walrus) scenarios. The results based on limited data are especially sensitive to the choice of alternative resampling scheme. [ABSTRACT FROM PUBLISHER]

The comment by Romero and Kannada is presented as a critique of our previous work and suggests that our conclusions are in direct conflict with the historic whaling information reviewed in their paper. However, the critique is based on a misinterpretation of the geographical, temporal, and taxonomic focus of our previous work. The source of the putative conflict appears to stem from the misinterpretation that our results, focused solely on the impact of Basque whaling in the 16th and 17th centuries on the western North Atlantic right whale, were intended to be representative of all whaling of both right and bowhead whales throughout the North Atlantic. To demonstrate this, we briefly review our original results and conclusions and show that the information reviewed by Romero and Kannada does not challenge any aspect of our original work. As such, their comment is not a critique of our paper, but rather a brief review of the history of whaling in the North Atlantic. [ABSTRACT FROM AUTHOR]

Concerns exist regarding the health and nutrition of subsistence-based communities in Alaska. An apparent increase in diabetes, heart disease, obesity, and other disease conditions among Alaska Natives has accompanied their change from a traditional diet to a more "Western" diet. In northern Alaska, the meat, maktak (epidermis and blubber), and other products of bowhead whales provide important components of Native diets. This study assessed the fatty acid constituents of bowhead whale blubber to evaluate their possible health benefits. Working with hunters in Barrow, Alaska, we acquired samples for chemical analysis from five blubber depths at each of six body locations. We used gas chromatography-mass spectrometry of fatty-acid picolinyl esters to confirm the fatty-acid composition of samples. Analyses indicated that bowhead blubber contains relatively high levels of omega-3 fatty acids and that, on average, blubber samples from sites at the umbilical girth contain more omega-3 fatty acids than do samples from a girth 1 m caudal to the blowhole (roughly at the axillary girth). Omega-6 fatty acids were rare or undetectable in all samples. Omega-3 fatty acids have been suggested or shown to be important in the treatment or prevention of many diseases, including elevated blood pressure and cholesterol, heart disease, stroke, diabetes, arthritis, depression, and some cancers. Beyond the cultural benefits associated with subsistence hunting of bowhead whales, consumption of bowhead whale blubber provides some important health and nutritional benefits. [ABSTRACT FROM AUTHOR]

Abstract: Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon (δ 13C) and nitrogen (δ 15N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator–prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator–prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator–prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on δ 15N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean δ 15N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals. [Copyright &y& Elsevier]

The article reports on the implications of sea ice cover on the bowhead whales' habitat in the western Arctic. The effects of sea ice cover on bowhead whale's, Balaena mysticetus, prey availability suggests that the diminution in sea ice cover will significantly increase prey availability. The western Arctic marine ecosystem is also inherently adaptable for bowhead whales and it opposes basin-scale characterization of extreme sea ice retreats, thinning, and wind-driven movements. Open water accrued accordingly in five small regions where bowhead whales were feeding or where prey availability were present, including the northern Chukotka coast and Beaufort slope in June; near Wrangel Island, Barrow Arc and Chukchi Borderland in September; and in Barrow Arc in November.

Nineteen years (1982-2000) of sighting data from fall aerial surveys of bowhead whales (Balaena mysticetus) in the Alaskan Beaufort Sea were analyzed to determine how patterns in the distribution of migrating bowhead whales relate to annual sea-ice conditions. Transect sighting rate (transect sightings/km) indicated (ANOVA; F2, 980 = 143.84, p < 0.0001) that bowhead whales occurred farther offshore in years of heavy ice conditions (73.4 km, 95% CL: 67.2-79.6 km) than in years of moderate (49.3 km, 95% CL: 44.8-53.84 km), or light (31.2 km, 95% CL: 30.0-32.4 km) ice conditions. The most plausible explanation for the observed pattern in bowhead whale distribution is that in years of heavy ice conditions (annual pack ice; 1983, 1988, 1991), the developing landfast ice limits availability of shallow nearshore habitat, thus necessitating use of leads and ice openings in deeper water. We acknowledge that factors such as bathymetry, ocean currents, transport, and food availability may also interact to influence autumn distribution of bowhead whales. In heavy ice years, however, these factors likely exert less influence on bowhead whale distribution than in years with light to moderate ice conditions. [ABSTRACT FROM AUTHOR]

Abstract: Tissues of bowhead, beluga, and gray whales were analyzed for Ag, Cd, Cu, Se, Zn, THg and MeHg (belugas only). δ15N and δ13C in muscle were used to estimate trophic position and feeding habitat, respectively. Trace element concentrations in tissues were significantly different among whale species. Hepatic Ag was higher in belugas than bowheads and gray whales. Gray whales had lower Cd concentrations in liver and kidney than bowhead and belugas and a sigmoid correlation of Cd with length was noted for all whales. Renal and hepatic Se and THg were higher in belugas than in baleen whales. The hepatic molar ratio of Se:THg exceeded 1:1 in all species and was negatively correlated to body length. Hepatic and renal Zn in subsistence-harvested gray whales was lower than concentrations for stranded whales. Se:THg molar ratios and tissue concentrations of Zn may show promise as potential indicators of immune status and animal health. [Copyright &y& Elsevier]

The article discusses the decline in the Greenland-Spitzbergen eastern Arctic bowhead whale population from its pristine level in 1611 to its extinction in 1911. Historical data on European commercial whaling were used to estimate the annual population of the Greenland-Spitzbergen stock of bowhead whales. A detailed description of the delayed difference recruitment model is also presented. It is noted that there is a relationship between the observed changes in the stock size and the changes in the economic environment following the commercial exploitation of bowhead whales.

Red blood cell (RBC) aggregation and blood viscosity are important determinants of in vivo blood flow dynamics and, in marine mammals, these parameters may impact diving physiology by altering blood oxygen delivery during the diving response. Weddell seals are superb divers and exhibit age-related patterns in blood oxygen chemistry and diving ability. By contrast, bowhead whales are not long duration divers, and little is known of their blood properties relative to diving. The present study was designed to compare rheological characteristics of blood from Weddell seal pups, Weddell seal adults, and from adult bowhead whales: blood viscosity and RBC aggregation in plasma and in polymer solutions (i.e., RBC “aggregability”) were measured. Salient findings included: (1) significant 4- to 8-fold greater aggregation in blood from adult seals compared with pups and human subjects; (2) 2-to 8-fold greater aggregation in bowhead whale blood compared with human blood; (3) compared to human red cells, enhanced RBC aggregability of RBC from adult seals and whales as determined by their greater aggregation in polymer solutions; (4) increasing RBC aggregation and aggregability of seal pup blood over a seven day period following birth; (5) significantly greater blood viscosity for adult seals compared with pups at both native and standardized hematocrits. These results indicate that, for both species, hemorheological parameters differ markedly from those of humans, and suggest progressive changes with seal age; the physiological implications of these differences have yet to be fully defined. [ABSTRACT FROM AUTHOR]

Nine bowhead whales (Balaena mysticetus) were instrumented with satellite transmitters in West Greenland in May 2002 and 2003. Transmitters were either encased in steel cans or imbedded in floats attached to wires. Transmitters mounted in steel cans had a high initial failure rate, yet those that were successful provided tracking durations up to seven months. Float tags had a low initial failure rate and initially provided large numbers of positions; however, they had deployment durations of only 2–33 d. All tracked whales departed from West Greenland and headed northwest towards Lancaster Sound in the end of May. Three tags with long tracking durations (197–217 d) recorded movements of whales (12642,22640) into December in 2002 and 2003. All of these individuals remained within the Canadian High Arctic or along the east coast of Baffin Island in summer and early fall. By the end of October, all three whales moved rapidly south along the east coast of Baffin Island and entered Hudson Strait, an apparent wintering ground for the population. One of the whales did not visit Isabella Bay on east Baffin Island, the locality used for abundance estimation from photographic reidentification of individuals. The movements of whales tagged in this study raise critical questions about the assumed stock discreteness of bowhead whales in Foxe Basin, Hudson Strait, and Davis Strait and indicate current estimates of abundance are negatively biased. [ABSTRACT FROM AUTHOR]

By the end of the 19th century, European whalers had brought the bowhead whale ( Balaena mysticetus) in the “Spitsbergen stock” ranging the waters between eastern Greenland and the western Russian Arctic to the verge of extinction. This paper presents observations of this species in Northeast Greenland and in the Greenland Sea between 1940 and 2004. The number of observations has increased in Northeast Greenland since the mid-1980s. Only three observations are known for the period 1940–1979 but during the 1980s, the 1990s and between 2000 and 2004, six, six and eight observations of bowhead whales were made, involving an absolute minimum of three, five and eight to ten different individuals, respectively. It remains uncertain whether this represents an increase in survey effort, an immigration from other areas, a recent recovery of an eastern Greenland relict “tribe” belonging to the Spitsbergen stock, or a combination of these factors. [ABSTRACT FROM AUTHOR]

We have extracted, digitized, and analyzed information about bowhead whales, Balaena mysticetus, contained in records of whaling cruises that were undertaken in the Bering, Chukchi, and Beaufort Seas from 1849 to 1914. Our database consists of 65,000 days of observations which provide insights into whether this bowhead stock may comprise more than one population. [ABSTRACT FROM AUTHOR]

Bowhead whales (Balaena mysticetus) hauled out on shore-fast ice by Inupiat whale hunters off Barrow. Alaska were examined. Anatomical observations confirmed the occurrence of a large, well-muscled tongue. Temporomandibular articulations were synovial. The mandibular symphysis was unfused. Standard measurement of baleen plates and close-range photogrammetry of a baleen rack confirmed that the anterior portion of the baleen rack is strongly convex, in contrast to its shape in balaenopterids. Moderate force applied to the lower lip in a lateral direction caused a pronounced abduction of the lower jaw. These observations support a conclusion that during feeding the tongue may deflect the incoming flow of prey-laden water from side to side in the mouth. to convey prey slurries into the postlingual recess. Abduction of the lower lip likely would establish a channel for acceleration of flow around the outside of the baleen racks, reducing external pressures and drawing water out through the baleen. Thus, the shape of the baleen rack in the bowhead appears to be an adaptation to reduce the amplitude of the bow wave projected during feeding, the simultaneous advantage being concentration of prey slurries inside the mouth. It may also impart a configuration to the bow wave that stimulates counter-effective evasive effort by actively mobile prey. Final compaction of a concentrated prey slurry in the postlingual recess probably involves retraction of the tongue against the oropharyngeal wall. These insights notably enable consideration of certain threats to bowheads and fight whales (Balaenidae) associated with oil spills and oral entanglement. Previous research on the "physiologic" effects of fouling of baleen with oil is judged to be inadequate with respect to this taxonomic family. Oral entanglement with nonbiodegradable marine debris is predicted to be lethal because of interference with a critical hydrostatic oral seal. [ABSTRACT FROM AUTHOR]

The 2001 survey of western Arctic (Bering, Chukchi, and Beaufort seas) bowhead whales was conducted from 5 April to 7 June near Barrow, Alaska. Visual observers recorded a total of 3,295 “new” (not seen before) and 532 “conditional” (possibly seen before) whales in 1,130 h of watch effort, including 121 new calves (3.7% of the new whales). Concurrent with the visual survey, passive acoustic surveillance was conducted almost continuously from 16 April to 31 May, resulting in 27,023 locations of vocalizing bowhead whales. The estimated number of whales within 4 km of the perch (N4) was 9,025 (SE = 1,068). The estimated proportion of the whales within 4 km of the perch (P4) was 0.862 (SE = 0.044, computed by a moving blocks-bootstrap). Combining these, the abundance estimate (N4/P4) for 2001 is 10,470 (SE = 1,351) with a 95% confidence interval of 8,100–13,500. The estimated annual rate of increase (ROI) of the population from 1978 to 2001 is 3.4% (95% CI 1.7%–5%). Reports from hunters and results of an aerial survey in June 2001 indicate whales continued to pass Barrow after the survey had ended. In 2001 51% (572 h) of the watch was scored as occurring during “fair-excellent” visibility conditions, somewhat lower than the average for all surveys since 1978. Sea ice in the leads and fog were the principle environmental factors affecting visibility for all years. The estimated rate of increase and the fact that the number of calves counted in 2001 is the highest ever recorded suggest a steady recovery of this population. Other populations of large balaenids, notably the North Atlantic right whale, have failed to recover despite 70 yr of protection. The recovery of the bowhead whale is likely attributable to low anthropogenic mortality, a relatively pristine habitat, and a well-managed subsistence hunt. Nonetheless, offshore oil development, increasing shipping traffic, changes in the Bering Sea ecosystem, sea ice retreat, and possibly killer whale predation within its range could impact this bowhead population and should be carefully monitored. [ABSTRACT FROM AUTHOR]

Anatomical and behavioral analyses suggest that the filtration mechanism of bowhead and right whales (Balaenidae) is driven by hydrodynamic as well as ram hydraulic pressures. Complementary models were devised to investigate biomechanical aspects of water flow in the buccal cavity of the bowhead whale Balaena mysticetus during continuous filter feeding. A mathematical model was created to test and quantify water flow predictions with steady state hydromechanical equations; a physical model of the bowhead mouth (approximately 1/15 scale) was constructed to visualize flow processes. Both models rely on morphometric data obtained from whales harvested by Inupiat Eskimos for subsistence purposes along with information on foraging ecology (locomotor velocity, gape, etc.). Results indicate that unique features of balaenid oral construction and function (e.g. subrostral gap, orolabial suicus, curvature of baleen, extensive mandibular rotation and lingual mobility) not only permit steady, unidirectional flow of water through the mouth, but also establish Bernoulli and Venturi effects during feeding. These hydrodynamic conditions allow balaenids to improve filtering efficiency and avoid creation of an anterior compressive wave (by increasing flow velocity and thereby reducing pressure) so that they may capture elusive prey even at slow swimming speeds. [ABSTRACT FROM AUTHOR]

This study presents the results of shore-based counts of bowhead whales (Balaena mysticetus) along the Chukotka Peninsula in 1999, 2000, and 2001. These counts confirmed that at least a small proportion of the Bering­Chukchi­Beaufort Seas Stock migrates along the western Bering Strait in late spring. The results of the counts in the Bering Strait were somewhat consistent between years. Taking into account that the whales passed by rapidly at great distances, we believe the number of whales seen during these counts is an underestimate of the actual number of whales migrating through the area. Our results indicate that the beginning of the spring migration of bowhead whales out of the Gulf of Anadyr varies by up to 30 days between cold and mild years, but in both cases, the area migration continues at least until 20 June. During the spring migration in the western Bering Strait, at the exit from the Gulf of Anadyr, whales moved over a broad front from near shore out to sea. When the directed migration began in May, the whales were not (or were seldom) observed to rest, feed, or engage in social behavior. Instead, we saw whales traversing long distances under water, swimming at speeds considerably faster than those of bowhead whales noted previously at Point Barrow. [ABSTRACT FROM AUTHOR]

A temporal record of environmental conditions is often contained within accretionary biological tissue. These records can provide knowledge of the environmental conditions that existed at the time the tissue was formed. In this study, we look at trace element concentrations and isotopic ratios of carbon and nitrogen as contained in baleen from bowhead whales in the eastern and western Arctic Ocean. Time series techniques, including maximum likelihood method and likelihood ratio tests, are applied to analysis of data and inference about their mean structures. [ABSTRACT FROM AUTHOR]

Temperature regulation in bowhead whales, Balaena mysticetus, is supported by the characteristic cetacean peripheral circulation, especially notable in the tail flukes. Blood vessels serving this function consist of countercurrent heat exchangers (network of veins surrounding a central artery) favoring heat conservation and an alternate routing via arteriovenous anastomoses (AVAs) providing for heat dissipation. We tested the vasomotor responses of isolated segments of countercurrent arteries and AVAs from the bowhead tail flukes to norepinephrine (NOR), the sympathetic adrenergic neurotransmitter. Isometric tension developed during exposure to a micromolar concentration of NOR was consistently higher in AVAs than in arteries. Accordingly, the AVAs are subject to sympathetic vasoconstriction, and this activation directs blood flow to countercurrent heat exchangers and results in heat conservation. In contrast, AVA relaxation by reduced sympathetic activation favors increased blood flow through AVAs and consequent peripheral heat loss. [ABSTRACT FROM AUTHOR]

Bowhead whale (Balaena mysticetus) blubber (n = 20) and plasma (n = 19) samples were collected during the 1997 to 2000 Inuit subsistence harvests in Barrow, Alaska, USA, to quantify the concentrations of methylsulfone (MeSO2)-containing and hydroxylated (OH) polychlorinated biphenyl (PCB) metabolites in this cetacean. The distribution of MeSO2-PCBs in blubber was dominated by 4-MeSO2-substituted congeners, the most abundant being 4-MeSO2-CB-70, 3′-MeSO2-CB-132, and 4-MeSO2-CB-64. Mean (61 standard error) sum (Σ) MeSO2-PCBs concentrations in blubber were low (6.23 ± 0.81 ng g&sup-1; lipid normalized) compared to concentrations previously reported in other marine mammals. However, similar ratios of MeSO2-PCB metabolites to parent PCB congeners among marine mammals suggest that cytochrome P450 2B-like biotransformation and other necessary enzyme-mediated processes and mechanisms that influence the formation and clearance of MeSO2-PCBs exist in the bowhead whale. Pentachlorophenol was the most abundant halogenated phenolic compound quantified in bowhead plasma (1.55 ± 0.19 ng g&sup-1; wet wt). Despite indirect evidence for arene epoxidation of the biphenyl moiety inferred from MeSO2-PCB formation, SOH-PCB concentrations in bowhead plasma were low (1.52 ± 0.31 ng g&sup-1; wet wt) compared to humans and marine mammals and were comprised of only two detectable ΣOH-PCB congeners (4′-OH-CB-130 and 4-OH-CB-187). Further research is required to elucidate the toxicokinetics and distribution of OH-PCBs in this cetacean. [ABSTRACT FROM AUTHOR]

Discusses historical population characteristics of bowhead whales or Balaena mysticetus in Hudson Bay. Biases in the data; Implications for stock structure; Trends in historical distribution.

To determine whether Hudson Bay-Foxe Basin bowhead whales segregate on the basis of age, whales summering in northern Foxe Basin, were aerially photographed in August of 1996, 1997, and 1998. Image lengths on either the negatives or contact prints were measured and total body lengths were estimated. In all three years the majority of whales photographed were ≤13.5 m long. Calves and juveniles made up 89.3%, 96.6%, and 79.3% of the total number of measured whales in 1996 (n = 28), 1997 (n = 30) and 1998 (n = 29) respectively. The number of bowheads >13.5 m, the approximate size at which females reach sexual maturity, that were photographed was directly proportional to the number of calves photographed. Our results indicate that northern Foxe Basin bowheads are part of a more widely distributed stock. Adult males and resting adult females apparently summer in another part of the range, probably northwestern Hudson Bay. Northern Foxe Basin appears to be used as a summer feeding area by cows with young-of-the-year calves and by juveniles. [ABSTRACT FROM AUTHOR]

Five bowhead whales (Balaena mysticetus) were instrumented with satellite transmitters in northwestern Disko Bay, West Greenland, in May 2001. Best results were obtained when tags were deployed with a pole rather than a pneumatic gun. At least three of the tagged whales remained in the northwestern part of the bay for one to two weeks after tagging. A male and a female whale moved from Disko Bay to northern Canada. They left Disko Bay 11 days apart and took different routes across Baffin Bay to the southern part of the North Water polynya, just east of the entrance to Lancaster Sound. The whales crossed the central part of Baffin Bay relatively rapidly (travel time of 9-10 days, 3.1 and 4.5 km/h). Dive behaviour of one whale was monitored and showed changes in dive depths, dive rates, and surfacing times in different localities, indicating behavioural changes probably related to feeding. The whales were presumably feeding in both Disko Bay in May and in the southern part of the North Water (southeast of Bylot Island) in June. This study confirms whalers' observations that bowhead whales move between West Greenland and the east coast of Baffin Island. [ABSTRACT FROM AUTHOR]

Rare remains of postglacial bowhead whales occur in the Norwegian Bay-Eureka Sound region. These are the northernmost remains known from the Canadian Arctic. The region is beyond the bowhead's current range because of persistent summer sea ice. We argue that the region has been beyond the bowhead's range for most of postglacial time for the same reason. With one exception, the 16 known subfossil bowheads from the region date to the last 4000 [sup 14]C years. Within the region, whale bones are most common adjacent to polynyas, which connect to more southerly channels extending from Baffin Bay. This distribution suggests that the polynyas, which here occupy areas of strong currents, developed as a result of shallowing of interisland channels due to postglacial uplift. The whale remains beyond the polynyas are seen as those of doomed strays that reached the polynyas from Baffin Bay and foraged farther along coastal leads before being trapped by freeze-up. This interpretation of Holocene sea-ice history agrees with the limited development of Holocene raised beaches in the region. However, it contradicts other interpretations of greatly ameliorated marine conditions in northernmost Canada at about 6000 [sup 14]C years B.P. [ABSTRACT FROM AUTHOR]

All International Whaling Commission assessments of the Bering-Chukchi-Beaufort Seas stock of bowhead whales (Balaena mysticetus) rely on likelihood functions derived from nearly the same data and a particular family of population dynamics models. Eleven such past bowhead assessments are compared. We note that the type of dynamics model used in all of these assessments has a strong influence on the features of the likelihood surface. We examine how the likelihood surface created by such models exhibits a narrow, cusp-shaped, flat-topped, steep-edged ridge of strong nonlinear dependency between key model parameters. We discuss how such features are generally troublesome for statistical inference and interpretation. Through examples we examine some of the implications for maximum likelihood estimation and the parametric bootstrap. Although such a dynamics model is very useful for producing realistic population trajectories, it is a poor model from which to generate likelihood functions in this case because it and the data together establish a nearly chaotic dynamical nonlinear system. [Copyright &y& Elsevier]

ABSTRACT The International Whaling Commission (IWC) recognizes aboriginal subsistence whaling to be distinct from commercial whaling, and these two broad categories of whaling are subject to different management approaches. This paper describes recent, ongoing and likely future whale hunts that qualify, or may qualify, for aboriginal subsistence status within the IWC’s management framework. To ensure conservation of the whale populations, a forthright exposition of the origins, development and character of these hunts is needed in addition to stock assessment, a risk-averse catch limit algorithm and appropriate mechanisms within the whaling communities to ensure compliance. The hunts for Bowhead Whales (Balaena mysticetus ) and Gray Whales (Eschrichtius robustus ) in the Arctic and North Pacific, respectively, and Sperm Whales (Physeter macrocephalus ) in Indonesia have long histories and local origins. Those for Humpback Whales (Megaptera novaeangliae ) in the Lesser Antilles and at Tonga in the South Pacific were introduced by foreign commercial whalers. Whale hunting in the Philippines appears to have originated both locally and as a result of foreign influence. The relatively recent initiation of whaling for Fin Whales (Balaenoptera physalus ) and Minke Whales (Balaenoptera acutorostrata ) in Greenland required introduced technology but can be viewed as a modern adaptation of an ancient tradition. Consensus in deciding how to classify and manage non-industrial whaling has been, and will remain, elusive. Even with common definitions of key terms such as ‘subsistence’, ‘commercial’ and ‘aboriginal’, interpretations will depend on whether one’s priorities are whale-centred or human-centred. [ABSTRACT FROM AUTHOR]

Examines on the polychlorinated biphenyl (PCB) concentrations and enantiomeric fractions in bowhead whales. Collection of blubber and liver samples; Properties of enantiomers; Quantity of PCB concentrations in bowhead whale blubber.

Short-term behavioral responses of bowhead whales (Balaena mysticetus) and beluga whales (Delphinapterus leucas) to a Bell 212 helicopter and Twin Otter fixed-wing aircraft were observed opportunistically during four spring seasons (1989-1991 and 1994). Behaviors classified as reactions consisted of short surfacings, immediate dives or turns, changes in behavior state, vigorous swimming, and breaching. The helicopter elicited fewer detectable responses by bowheads (14% of 63 groups) than by belugas (38% of 40). Most observed reactions by bowheads (63%) and belugas (86%) occurred when the helicopter was at altitudes ≤ 150 m and lateral distances ≤250 m. Belugas reacted significantly more frequently during overflights at lateral distances ≤250 m than at longer lateral distances (P = 0.004). When the helicopter was on the ice with engines running, 7 of 14 groups of belugas reacted, up to 320 m away, sometimes with smallscale (≤100 m) diversion; only 1 of 8 groups of bowheads reacted. For the fixed-wing aircraft, few bowheads (2.2%) or belugas (3.2%) were observed to react to overflights at altitudes 60-460 m. Most observed reactions by bowheads (73%) and belugas (70%) occurred when the fixed-wing aircraft was at altitudes ≤182 m and lateral distances ≤250 m. However, the proportions reacting, especially to low-altitude flights (e.g., ≤182 m), were underestimated for both species because observation opportunities were brief. Even so, reactions were more common when the aircraft was low (≤182 m): P = 0.009 for belugas, P = 0.06 for bowheads. There was little if any reaction by bowheads when the aircraft circled at altitude 460 m and radius 1 km. Aircraft sounds measured underwater at depths 3 m and 18 m showed that a Bell 212 helicopter was 7-17.5 dB noisier than a Twin Otter (10-500 Hz band). Bell 212 sound consisted mainly of main rotor tones ahead of the helicopter and tail rotor tones behind it. Twin Otter sound contained fewer prominent... [ABSTRACT FROM AUTHOR]

Inorganic mercury was localized through autometallography (AMG) in kidney and liver of free-ranging, subsistence-harvested beluga (Delphinapterus leucas; n 20) and bowhead (Balaena mysticetus; n 5) whales. AMG granules were not evident in bowhead tissues, confirming nominal mercury (Hg) concentrations (range 0.011 to 0.038 ug/g ww for total Hg). In belugas, total Hg ranged from 0.30 to 17.11 and from 0.33 to 82.47 ug/g ww in liver and kidney, respectively. AMG granules were restricted to cortical tubular epithelial cytoplasm in belugas with lower tissue burdens; whales with higher tissue burdens had granules throughout the uriniferous tubular epithelium. In liver, AMG granular densities differed between lobular zones, concentrating in stellate macrophages and bile cannalicular domains of hepatocytes. AMG granules aggregated in periportal regions in belugas with lower hepatic Hg concentrations, yet among whales with higher Hg, AMG granule deposition extended to pericentral and midzonal regions of liver lobules. Mean areas occupied by AMG granules correlated well with hepatic Hg concentrations and age. In beluga livers, AMG staining density was not associated with lipofuscin quantity (an index of oxidative damage). Occasionally, AMG granules and lipofuscin were colocalized, but more often were not, implying that Hg was not a prominent factor in hepatic lipofuscin deposition in belugas. [ABSTRACT FROM AUTHOR]

In this study, stable carbon, nitrogen, and sulphur isotope ratios were measured in muscle tissue from the Bering Chukchi Beaufort Sea population of bowhead whales, Balaena mysticetus. The Bering Chukchi Beaufort Sea stock migrates annually between the eastern Beaufort Sea in the summer and northern Bering Sea in the winter. Stable nitrogen isotope values and assigned trophic levels calculated in this study are in agreement with current knowledge on the diets of Arctic marine species. Bowhead whales were found to have significantly different nitrogen isotope signatures than other marine biota. A significant seasonal oscillation in carbon isotopes values between whales landed in the fall and spring was observed. Seasonal changes in feeding habits of the bowhead whale with increasing age, as interpreted from body length, were investigated by determining the carbon isotope values in fall- and spring-harvested specimens. This is the first study to report the stable sulphur isotope values in species within this study region. More research is required to determine the effects of physiological stress on stable-isotope fractionation in biological systems. This investigation has provided additional understanding of the trophic ecology of the Bering Chukchi Beaufort Sea bowhead whale population relative to that of other marine species in the Alaskan and western Canadian Arctic marine environment.

Provides information on a study that reconstructed the size of the bowhead whale population and established the chronology of its extinction in the Eastern Arctic. Data used; Results; Conclusions.

Presents a study to investigate the quantitative data regarding the eyes of 46 bowhead whales near Barrow, Point Hope, Savoonga, and Kaktovik, Alaska. Consideration of dimensions measuring the palpebral, eyeball, corneal, scleral, pupillary, and lens; Findings of a correlation between body length and eyeball size; Absence of an obvious fovea or macular region in the retina; Consideration of a holangiotic pattern of fundic vessels; Characteristics of zonular fibers and a lens sheath; Use of the retractor bulbi muscle as a mechanism for the protrusion and retraction of the eyeball.

Comments on an article regarding the use of Bayesian approach for modeling fetal growth and gestation in bowhead whales. Modeling choices in shape and dispersion; Research about the wider context of whale population research and management; Information about the Bayesian methodology, which is quite useful in several other issues in whale research, such as migration and abundance estimation.

Comments on the limitations of estimability from fetal collections in an article by leading mathematician C. Shane Reese regarding the use of Bayesian approach for modeling fetal growth and gestation in bowhead whales. Historical background on the study of whale populations; Utilization of Bayesian methods in the natural resources field; Speculation on further work that can take advantage of the Bayesian hierarchical approach.

We address estimating fetal growth and gestation for bowhead whales of the Bering, Chukchi, and Beaufort seas stock. This population is subject to a subsistence hunt by Eskimo whale hunters, which is monitored via a quota system established by the International Whaling Commission. Quota determination is assisted by biological information, such as fetal growth and gestation, which is the basis of a population dynamics model used to estimate the annual replacement yield of the stock. We developed a Bayesian hierarchical nonlinear model for fetal growth with computation carried out via Markov chain Monte Carlo techniques. Our model allows for unique conception and parturition dates and provides predictive distributions for gestation length and conception dates. These results are used to propose estimates of geographic locations for conception and parturition. A sensitivity analysis indicated caution when specifying some hyperparameters related to growth rate, conception dates, and parturition dates. [ABSTRACT FROM AUTHOR]

Presents a study which examined the bowhead whale historical population size fluctuations in a phylogenetic context. Review of related literature; Materials and methods used; Results and discussion.

Discusses the natural history and conservation of the Greenland whale, or bowhead (Balaena mysticetus) in the northwest Atlantic Ocean. Near extinction due to commercial whaling; Failure to show demonstrable population recovery in the last century; Factors that may affect recovery; Need for local and historical knowledge to understand the bowhead's natural history.