Erik Wolder Born

In this pilot study, we report on levels of persistent organohalogenated contaminants (OHCs) in hair of polar bears (Ursus maritimus) from East Greenland sampled between 1999 and 2001. To our knowledge, this is the first study on the validation of polar bear hair as a non-invasive matrix representative of concentrations and profiles in internal organs and blood plasma. Because of low sample weights (13-140mg), only major bioaccumulative OHCs were detected above the limit of quantification: five polychlorinated biphenyl (PCB) congeners (CB 99, 138, 153, 170 and 180), one polybrominated diphenyl ether (PBDE) congener (BDE 47), oxychlordane, trans-nonachlor and β-hexachlorocyclohexane. The PCB profile in hair was similar to that of internal tissues (i.e. adipose, liver, brain and blood), with CB 153 and 180 as the major congeners in all matrices. A gender difference was found for concentrations in hair relative to concentrations in internal tissues. Females (n=6) were found to display negative correlations, while males (n=5) showed positive correlations, although p-values were not found significant. These negative correlations in females may reflect seasonal OHC mobilisation from periphery adipose tissue due to, for example, lactation and fasting. The lack of significance in most correlations may be due to small sample sizes and seasonal variability of concentrations in soft tissues. Further research with larger sample weights and sizes is therefore necessary to draw more definitive conclusions on the usefulness of hair for biomonitoring OHCs in polar bears and other fur mammals.

... MiljV7-ognaturforvalining, 8. 126 pp. (in Danish with an English suiumary ). Born, EW andThomassen, J., 1994. Polar bear studies. ... ln: L. Rey (Editor), The Arctic Ocean. The Hydrographic Environment and the Fate of Pollutants. Macmillan P-ess, London, pp. 83-96. ...

Within their circumpolar range, polar bears (Ursus maritimus) are not subject to absolute barriers. However, physiographic features do cause discontinuities in their movements. These discontinuities in distribution can be used to delineate population units. Based on satellite telemetry of the movements of female polar bears carried out in 1989–1998, we used cluster analysis to identify 6 regions within the Canadian and western Greenland Arctic in which movements appear to be restricted enough to identify distinct populations. These regions generally correspond to management units that have been previously identified as Viscount Melville Sound, Lancaster Sound, Norwegian Bay, Kane Basin, Baffin Bay, and Davis Strait. A north–south substructure was identified for the Baffin Bay population, but it was weaker than the structure identified for the 6 primary units. The 6 units were consistent with genetic information, except for the Baffin Bay – Kane Basin separation, and with mark–recapt...

Age at sexual maturity among male polar bears (Ursus maritimus) and timing of the mating season were studied by microscopic and macroscopic analysis of the reproductive organs from 165 male and 92 female Greenland polar bears. Males became sexually mature in ...

Climate change is expected to result in range shifts and habitat fragmentation for many species. In the Arctic, loss of sea ice will reduce barriers to dispersal or eliminate movement corridors, resulting in increased connectivity or geographic isolation with sweeping implications for conservation. We used satellite telemetry, data from individually marked animals (research and harvest), and microsatellite genetic data to examine changes in geographic range, emigration, and interpopulation connectivity of the Baffin Bay (BB) polar bear () subpopulation over a 25-year period of sea-ice loss. Satellite telemetry collected from  = 43 (1991-1995) and 38 (2009-2015) adult females revealed a significant contraction in subpopulation range size (95% bivariate normal kernel range) in most months and seasons, with the most marked reduction being a 70% decline in summer from 716,000 km (SE 58,000) to 211,000 km (SE 23,000) ( < .001). Between the 1990s and 2000s, there was a significant shif...

The historical and current dynamics of the three Atlantic walrus (Odobenus rosmarus rosmarus) populations that occur in Greenland are estimated using age- and sex-structured population models with exponential growth, density-regulated growth and selection-delayed dynamics. These models are integrated with data in a Bayesian framework, where the likelihood of the simulated population trajectories are evaluated from recent abundance estimates and age-structure information from a selective hunt. The overall decline in the Baffin Bay population caused by historical catches is unclear due to incomplete catch reporting prior to 1950s. However, it is estimated that the population declined by 40% from the 1960s to 2005; decreased catches (≈ 140 to ≈ 70) have subsequently allowed this population to increase. The 2012 abundance estimate is 1,400 (95% CI: 1,000-2,000) individuals, and the annual natural growth rate in this population is now 7.7% (95% CI: 6.7-8.9%). Averaging across models, it ...

Polar bears (Ursus maritimus) occupy remote regions that are characterized by harsh weather and limited access. Polar bear populations can only persist where temporal and spatial availability of sea ice provides adequate access to their marine mammal prey. Observed declines in sea ice availability will continue as long as greenhouse gas concentrations rise. At the same time, human intrusion and pollution levels in the Arctic are expected to increase. A circumpolar understanding of the cumulative impacts of current and future stressors is lacking, long-term trends are known from only a few subpopulations, and there is no globally coordinated effort to monitor effects of stressors. Here, we describe a framework for an integrated circumpolar monitoring plan to detect ongoing patterns, predict future trends, and identify the most vulnerable polar bear subpopulations. We recommend strategies for monitoring subpopulation abundance and trends, reproduction, survival, ecosystem change, huma...

In the Arctic, polar bears (Ursus maritimus) bio-accumulate mercury as they prey on polluted ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arctic. It is unknown whether these levels are toxic to liver and kidney tissue. We investigated the histopathological impact from anthropogenic long-range transported mercury on East Greenland polar bear liver (n = 59) and kidney (n = 57) tissues. Liver mercury levels ranged from 1.1-35.6 microg/g wet weight and renal levels ranged from 1-50 microg/g wet weight, of which 2 liver values and 9 kidney values were above known toxic threshold level of 30 microg/g wet weight in terrestrial mammals. Evaluated from age-correcting ANCOVA analyses, liver mercury levels were significantly higher in individuals with visible Ito cells (p < 0.02) and a similar trend was found for lipid granulomas (p = 0.07). Liver mercury level...

Samples of lymph nodes (axillary, n = 54 and inguinal, n = 45), spleen (n = 60), thymus (n = 11) and thyroid tissue (n = 5) from a total of 82 polar bears (Ursus maritimus) collected in East Greenland 1999-2002 were examined histologically. The purpose was to relate histology to concentrations of organohalogen contaminants (OHCs) [i.e., sum (Sigma)PCBs, SigmaDDTs, SigmaHCHs, SigmaCHLs, HCB, Dieldrin and SigmaPBDEs] determined in adipose tissue, as studies on polar bears have indicated that some OHCs act as immunosuppressive agents. Secondary follicle counts were evaluated in spleen and lymph nodes, and semiquantitively divided into four groups (0: few/absent to 3: high). In the spleen, a high secondary follicle count was found in 21% of the cases (12/60), and this was significantly higher in subadults (p < 0.01) compared to adults of both sexes. Also in the lymph nodes a high secondary follicle count was found in 20% of the cases (20/99), and in the axillary lymph nodes changes w...

Fluctuating asymmetry (FA) was studied in skulls of 283 polar bears (Ursus maritimus) sampled in East Greenland from 1892 to 2002. Fourteen metric bilateral traits in skull and lower jaw were measured and compared between polar bears born until 1960 (n = 94) and from 1961 (n = 189). The period 1892-1960 was chosen to represent a period prior to appearance of organohalogens (polychlorinatedbiphenyls [PCBs], dichlorodiphenyltrichloroethanes [DDTs], hexacyclohexanes [HCHs], chlordanes [CHLs], hexachlorobenzene [HCB], polybrominateddiphenylethers [PBDEs] and dieldrin) originating from long-range transport to East Greenland from southern latitudes. The period 1961-2002 represents the period when polar bears have been exposed to organohalogens. During this latter period, the level of organochlorines is believed to have increased from 1960 to the late 1980s followed by a likely decrease from 1990 to 2002. Within this later period, other compounds such as, e.g., polybrominated flame retarda...

Direct observations of underwater behaviour of free-living marine mammals are rare. This is particularly true for large and potentially dangerous species such as the walrus (Odobenus rosmarus). Walruses are highly specialised predators on benthic invertebrates - especially bivalves. The unique feeding niche of walruses has led to speculations as to their underwater foraging behaviour. Based on observations of walruses in captivity and signs of predation left on the sea floor by free-living walruses, various types of feeding behaviour have been suggested in the literature. In this study, however, the underwater feeding behaviour of wild adult male Atlantic walruses (O. r. rosmarus) is documented for the first time in their natural habitat by scuba-divers. The video recordings indicated a predisposition for use of the right front flipper during feeding. This tendency towards dextrality was explored further by examining a museum collection of extremities of walrus skeletons. During Jul...

Persistent organochlorines [PCBs, DDT and chlordane related compounds, dieldrin, toxaphene, hexachlorocyclohexane (HCH), chlorobenzenes] were determined in blubber of Atlantic walrus (Odobenus rosmarus rosmarus) in 1978 and 1988 from the Avanersuaq (Thule) region of north-west Greenland and in 1989 from Ittoqqortoormiit (Scoresbysund) in east Greenland. Lowest concentrations of organochlorines (OCs) were found in the samples from the Avanersuaq region while much higher levels of all compounds, except HCH isomers and mono/dichlorobiphenyls (CB5/8), were observed in samples (all males) from Ittoqqortoormiit. Total PCBs (sigma PCB) averaged 246 ng/g (wet wt.) male walrus from Avanersuaq and 2860 ng/g in samples from Ittoqqortoormiit. DDT isomers showed the greatest difference between the two locations, 50 x for p,p'-DDE and 69 x higher for p,p'-DDT. Ittoqqortoormiit walrus showed the pattern of OCs characteristic of seal-eating animals although the consumption of other organism...

Information on mercury and selenium molar relation in muscle, liver and kidney tissue of Greenland marine animals is presented. In the majority of the samples selenium was present in a molar surplus to mercury. This was most clear in molluscs, crustaceans, fish and seabirds. A 1:1 molar ratio was found in tissues of marine mammals with high mercury concentrations (above approx. 10 nmol/g). This was most clearly demonstrated for liver and kidney tissue of polar bear and for ringed seal with high mercury concentration in the liver. These findings support previous results found in liver tissue of marine mammals, suggesting that methyl mercury is detoxified by a chemical mechanism involving selenium. If the anthropogenic release of mercury to the environment increases in the future due to increasing energy demands, species such as polar bears and seals with high tissue mercury concentrations should be monitored to elucidate whether this protective mechanism can be maintained in target o...

Arctic marine mammals (AMMs) are icons of climate change, largely because of their close association with sea ice. However, neither a circumpolar assessment of AMM status nor a standardized metric of sea ice habitat change is available. We summarized available data on abundance and trend for each AMM species and recognized subpopulation. We also examined species diversity, the extent of human use, and temporal trends in sea ice habitat for 12 regions of the Arctic by calculating the dates of spring sea ice retreat and fall sea ice advance from satellite data (1979-2013). Estimates of AMM abundance varied greatly in quality, and few studies were long enough for trend analysis. Of the AMM subpopulations, 78% (61 of 78) are legally harvested for subsistence purposes. Changes in sea ice phenology have been profound. In all regions except the Bering Sea, the duration of the summer (i.e., reduced ice) period increased by 5-10 weeks and by >20 weeks in the Barents Sea between 1979 and 2...

ABSTRACT Background/Question/Methods Foraging and reproductive success of wide-ranging and solitary predators depends on both encounters with prey and encounters between mates, often during a narrow breeding season. The primary tool for studying movements in polar bears (Ursus maritimus) has been satellite telemetry; however, few data have been collected from adult males due to limitations in transmitter attachment. We report movement data collected from n=23 adult male polar bears in two separate subpopulations inhabiting dynamic pack ice (East Greenland and Baffin Bay) tracked over 5 spring breeding seasons, 2007-2011. Data were collected with a satellite-linked transmitters attached to the ear. We compared these movements with those of n=27 adult females tagged concurrently with satellite collars during the spring breeding season (April-May), and analyzed velocities, tortuosity of movements, kernel home range sizes, and habitat selection with respect to sex, age, reproductive status and body mass. Our objectives were to examine differences in movement behavior between the sexes during the breeding season and examine how this may impact potential mate encounters at low densities on the sea ice. Results/Conclusions There were no significant differences in the mean 4-day displacement between sex or population. Nor were there differences between sexes in habitat models estimating selection for satellite-derived sea ice concentration (%), distance to sea ice edge, and distance to shore. However, there were consistent and significant differences in linearity of movement, measured with a persistence index (0<PI<1), which was significantly higher for adult females (mean=0.43, sd=0.23) than adult males (mean=0.01, sd=0.19, p<0.001) in all years and in both populations. The 95% kernel range for females was also significantly larger than for males in both populations (p=0.001). We suggest that the more tortuous breeding season movements of adult males allow for a high probability of female mate encounter while avoiding competitive interactions with other males. Linear movements of females (independent of reproductive availability) are consistent with a prioritized search for sparsely distributed, low-probability prey (e.g. seals) over mate encounters. We interpret these results as the first evidence for some level of territoriality in pack-ice breeding male polar bears, which may have significant nearing on the rate of pair formation and the impacts of Allee effects.

Surveys to estimate walrus abundance at terrestrial haulout sites in the Penny Strait-Lancaster Sound (PS-LS) and West Jones Sound (WJS) stocks were conducted in 1977 and 1998-2009. The Minimum Counted Population (MCP) was similar in 1977 (565) to recent years (557) for the PS-LS stock. The MCP for the WJS stock was higher in recent surveys (404) than in 1977 (290). Regression analysis of MCP and density (number of walrus divided by number of haulouts surveyed) showed no significant trends over time. We also calculated bounded count estimates for comparison. Finally, we used broad-scale behavioural data to estimate the proportion of the total stock that could be considered countable, to produce two adjusted estimates. We selected recent surveys with good coverage and ignored adjusted estimates that were lower than MCP. For the PS-LS stock, the adjusted MCP (with 95% CL) was 672 (575-768) and 727 (623-831) walrus in 2007 and 2009, respectively. For WJS, the best estimates were the ad...

A statistically robust method was applied to 83 time-series of mercury in Arctic biota from marine, freshwater and terrestrial ecosystems with the purpose of generating a 'meta-analysis' of temporal trend data collected over the past two to three decades, mostly under the auspices of the Arctic Monitoring and Assessment Program (AMAP). Sampling locations ranged from Alaska in the west to northern Scandinavia in the east. Information from recently published temporal trend studies was tabulated to supplement the results of the statistical analyses. No generally consistent trend was evident across tissues and species from the circumpolar Arctic during the last 30years or so. However, there was a clear west-to-east gradient in the occurrence of recent increasing Hg trends, with larger numbers and a higher proportion of biotic datasets in the Canadian and Greenland region of the Arctic showing significant increases than in the North Atlantic Arctic. Most of the increasing datasets were for marine species, especially marine mammals. A total of 16 (19%) out of the 83 time-series could be classified as "adequate", where adequate is defined as the number of actual monitoring years in a time-series being equal to or greater than the number of years of sampling required to detect a 5% annual change in Hg concentrations, with a significance level of…

To support management objectives in Canada and Greenland, joint research between the Department of Fisheries and Oceans and Greenland Institute of Natural Resources was begun in 2005. Direct counts were used to determine the Minimum Counted Population (MCP) in summer around SE Baffin Island. Aerial surveys examined the coast from roughly the Saddleback Island in northern Hudson Strait to Isabella Bay on eastern Baffin Island but concentrated on the area between Loks Land and Cape Dyer. The maximum count was obtained on 3–4 September 2007 during boat surveys. The MCP ranged from 716 (in 2006) to 1,056 (2007). Using the largest MCP adjusted with published maximum estimates of the proportion of walrus hauled out concurrently, we estimated 1,420 (95% CI: 1,219–1,622) walrus were present. In addition, four walrus had been fitted with satellite relayed data logger tags prior to the maximum counts in 2007. Using the simple proportion of ‘tags dry’ on 3 September to adjust counts on 3 and 4...

The strict orthology of mitochondrial (mt) coding sequences has promoted their use in phylogenetic analyses at different levels. Here we present the results of a mitogenomic study (i.e., analysis based on the set of protein-coding genes from complete mt genomes) of 60 mammalian species. This number includes 11 new mt genomes. The sampling comprises all but one of the traditional eutherian orders. The previously unrepresented order Dermoptera (flying lemurs) fell within Primates as the sister group of Anthropoidea, making Primates paraphyletic. This relationship was strongly supported. Lipotyphla ("insectivores") split into three distinct lineages: Erinaceomorpha, Tenrecomorpha, and Soricomorpha. Erinaceomorpha was the basal eutherian lineage. Sirenia (dugong) and Macroscelidea (elephant shrew) fell within the African clade. Pholidota (pangolin) joined the Cetferungulata as the sister group of Carnivora. The analyses identified monophyletic Pinnipedia with Otariidae (sea li...

Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyper-lipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479-343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under strong positive selection are associated with cardiomyopathy and vascular disease, implying important reorganization of the cardiovascular system. One of the genes showing the strongest evidence of selection, APOB, encodes the primary lipoprotein component of low-density lipoprotein (LDL); functional mutations in APOB may explain how polar bears are able to cope with life-long elevated LDL levels that are associated with high risk of heart disease in humans.

Blood samples of live-caught polar bears (Ursus maritimus) from Svalbard collected 1991-2000 (Period 1) and 2006-2008 (Period 2) and from the pack ice of the Barents Sea collected in Period 1, were assayed for antibodies against Trichinella spp. by ELISA. Of 54 cubs-of-the-year included in the Period 1 sample, 53 were seronegative, indicating that exposure to Trichinella infected meat is uncommon during the first months of life for polar bears in the Svalbard region. Of 30 mother-offspring pairs, 18 mothers were seropositive with seronegative offspring (n=27), suggesting (1) that maternal antibodies had dropped to levels below detection limit by the time of capture in April (offspring approximately 4 months old), and (2) supporting experimental studies in other animal models showing that vertical transmission of Trichinella spp. is uncommon. Bear 1 year and older had higher prevalence in Svalbard (78%) than in the Barents Sea (51%). There was no temporal change in prevalence for bears from Svalbard during the time between the two periods. The prevalence increased with age in both sexes. A positive correlation was found between anti-Toxoplasma gondii and anti-Trichinella spp. antibodies.

... VMD, MVSc a * , Rossana Bossi b , Rune Dietz a , Pall S. Leifsson c , Frank F. Rigét a & Erik W. Born d pages 275-283. ... [Taylor & Francis Online], [PubMed], [Web of Science ®] View all references; however, these chemicals were also detected in remote areas such as the Arctic. ...

Deuterium oxide was used to measure isotope dilution space 11 times in seven free living, adult, male Atlantic walruses (Odobenus rosmarus rosmarus) (930–1597 kg) in north-east Greenland in the month of August 2000 and August 2001. Telemetry instruments, which were attached to the animals as part of a long term study, provided data on activity levels. Equilibration of the intravenously injected isotope was complete after 2–3 h. The application of a general correction factor developed for all pinniped species allowed the estimation of total body water content as 56.8% (range: 36.6–73.3%) of total body mass (TBM). Water turnover averaged 44.5 g kg-1 d-1. For one animal it was possible to estimate water influx to 4.8 g kg-1 d-1 and water efflux to 21.8 g kg-1 d-1. The estimates of body fat and body protein averaged respectively 24.7% and 18.4% of TBM. Similarly, for an ‘average’ walrus with a TBM of 1300 kg body ash was calculated to average 26 kg and body gross energy to 18,300 MJ. Th...

A 23-year-old female polar bear (Ursus maritimus) killed in an Inuit hunt in East Greenland on July 9, 1999 had a significantly enlarged clitoris resembling, in size, form and colour, those of previously reported 'pseudohermaphroditic' polar bears from Svalbard. It has been suggested that an enzyme defect (21-hydroxylase deficiency), androgen producing tumour or high exposure to organochlorines during the foetal stage or early development could be the reason for the supposed pseudohermaphroditism observed for Svalbard bears. Except for the enlarged clitoris, all dimensions of the external and internal reproductive organs of the present were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999-2002. The aberrant bear was a female genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively functional. A histological examination of the clitoral enlargement in the present East Greenland specimen allows a first-time histological evaluation of the earlier macroscopic field diagnosis from Svalbard. This examination revealed intense chronic ulcerative and perivascular clitoriditis similar to "acral lick dermatitis" frequently seen in domestic dogs (i.e., we did not find any signs of pseudohermaphroditic hyperplasia of clitoral tissue due to androgenic or antiestrogenic endocrine disruption). The levels of organohalogens and TEQ values were lower than concentration thresholds of toxicological risk. It is hence possible that the previously reported adult female polar bear pseudohermaphrodites from Svalbard are in fact misdiagnoses. Therefore, future studies examining pseudohermaphroditism in wildlife should consider that certain occurrences are natural events, e.g., enlarged clitoris in the present East Greenland polar bear. Furthermore, caution should be exercised in suggesting linkages of such inflammatory abnormalities with correlations to anthropogenic pollutant exposures.