| health effects from long-range transported contaminants in arctic top predators: an integrated review based on studies of polar bears and relevant model species. | the aim of this review is to provide a thorough overview of the health effects from the complexed biomagnified mixture of long-range transported industrial organochlorines (ocs), polybrominated diphenyl ethers (pbdes), perfluorinated compounds (pfcs) and mercury (hg) on polar bear (ursus maritimus) health. multiple scientific studies of polar bears indicate negative relationships between exposure to these contaminants and health parameters; however, these are all of a correlative nature and do n ... | 2010 | 20398940 |
| the functionality of the gastrointestinal microbiome in non-human animals. | due to the significance of the microbiome on human health, much of the current data available regarding microbiome functionality is centered on human medicine. for agriculturally important taxa, the functionality of gastrointestinal bacteria has been studied with the primary goals of improving animal health and production performance. with respect to cattle, the digestive functions of bacteria in cattle are unarguably critical to digestion and positively impact production performance. conversely ... | 2015 | 26552373 |
| genetic analysis of hair samples attributed to yeti, bigfoot and other anomalous primates. | in the first ever systematic genetic survey, we have used rigorous decontamination followed by mitochondrial 12s rna sequencing to identify the species origin of 30 hair samples attributed to anomalous primates. two himalayan samples, one from ladakh, india, the other from bhutan, had their closest genetic affinity with a palaeolithic polar bear, ursus maritimus. otherwise the hairs were from a range of known extant mammals. | 0 | 24990672 |
| polychlorinated biphenyls and their hydroxylated metabolites (oh-pcbs) in the blood of toothed and baleen whales stranded along japanese coastal waters. | in this study, we determined the residue levels and patterns of polychlorinated biphenyls (pcbs) and hydroxylated pcbs (oh-pcbs) in the blood from eight species of toothed whales and three species of baleen whales stranded along the japanese coast during 1999-2007. penta- through hepta-chlorinated pcb congeners were the dominant homologue groups in all cetaceans. in contrast, specific differences in the distribution of dominant oh-pcb isomers and homologues were found among the cetacean species. ... | 2010 | 20426459 |
| ursidibacter maritimus gen. nov., sp. nov. and ursidibacter arcticus sp. nov., two new members of the family pasteurellaceae isolated from the oral cavity of bears. | thirty-three suspected strains of the family pasteurellaceae isolated from the oral cavity of polar and brown bears were characterized by genotypic and phenotypic tests. phylogenetic analysis of partial 16s rrna gene and rpob sequences showed that the investigated isolates formed two closely related monophyletic groups, representing two novel species of a new genus. based on 16s rrna gene sequence comparison bibersteinia trehalosi was the closest related species with a validly published name, wi ... | 2015 | 26220443 |
| biomonitoring in greenland: human biomarkers of exposure and effects - a short review. | since 1997 the arctic monitoring and assessment programme (amap) has produced integrated assessment reports on the status of and trends in environmental persistent organic pollutants (pops) in the arctic ecosystem. three reports on biomonitoring pops and their health risks for arctic populations were published in 1998, 2002, and 2009. | 2010 | 20572746 |
| morbillivirus and toxoplasma exposure and association with hematological parameters for southern beaufort sea polar bears: potential response to infectious agents in a sentinel species. | arctic temperatures are increasing in response to greenhouse gas forcing and polar bears have already responded to changing conditions. declines in body stature and vital rates have been linked to warming-induced loss of sea-ice. as food webs change and human activities respond to a milder arctic, exposure of polar bears and other arctic marine organisms to infectious agents may increase. because of the polar bear's status as arctic ecosystem sentinel, polar bear health could provide an index of ... | 2010 | 20607348 |
| hematology of southern beaufort sea polar bears (2005-2007): biomarker for an arctic ecosystem health sentinel. | declines in sea-ice habitats have resulted in declining stature, productivity, and survival of polar bears in some regions. with continuing sea-ice declines, negative population effects are projected to expand throughout the polar bear's range. precise causes of diminished polar bear life history performance are unknown, however, climate and sea-ice condition change are expected to adversely impact polar bear (ursus maritimus) health and population dynamics. as apex predators in the arctic, pola ... | 2010 | 20617361 |
| complete genome sequence of equine herpesvirus type 9. | equine herpesvirus type 9 (ehv-9), which we isolated from a case of epizootic encephalitis in a herd of thomson's gazelles (gazella thomsoni) in 1993, has been known to cause fatal encephalitis in thomson's gazelle, giraffe, and polar bear in natural infections. our previous report indicated that ehv-9 was similar to the equine pathogen equine herpesvirus type 1 (ehv-1), which mainly causes abortion, respiratory infection, and equine herpesvirus myeloencephalopathy. we determined the genome sequ ... | 2012 | 23166237 |
| rickets in polar bear cubs: is there a lesson for human infants? | | 2011 | 20639682 |
| the value of a polar bear: evaluating the role of a multiple-use resource in the nunavut mixed economy. | the polar bear (ursus maritimus) is a common pool resource that contributes to both the subsistence and monetary aspects of the nunavut mixed economy through its use as food, the sale of hides in the fur trade, and sport hunt outfitting. sport hunting is more financially profitable than subsistence hunting; however, the proportion of the polar bear quota devoted to the sport hunt has become relatively stable at approximately 20% across nunavut. this ratio suggests local inuit organizations are n ... | 2010 | 20648983 |
| expanded spectrum of congenital ocular findings in microcephaly with presumed zika infection. | to describe the ocular findings of 3 cases of suspected congenital zika viral infection with microcephaly and maculopathy. | 2016 | 27236271 |
| brucella species survey in polar bears (ursus maritimus) of northern alaska. | we report on the presence of specific antibodies to brucella spp. and yersinia enterocolitica in polar bears (ursus maritimus) from northern alaska (southern beaufort sea) during 2003-2006. based on numerous known stressors (e.g., climate change and loss of sea ice habitat, contaminants), there is increased concern regarding the status of polar bears. considering these changes, it is important to assess exposure to potentially pathogenic organisms and to improve understanding of transmission pat ... | 2010 | 20688674 |
| serosurvey for trichinella in polar bears (ursus maritimus) from svalbard and the barents sea. | 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 ... | 2010 | 20797484 |
| a novel endogenous betaretrovirus group characterized from polar bears (ursus maritimus) and giant pandas (ailuropoda melanoleuca). | transcriptome analysis of polar bears (ursus maritimus) yielded sequences with highest similarity to the human endogenous retrovirus group herv-k(hml-2). further analysis of the polar bear draft genome identified an endogenous betaretrovirus group comprising 26 proviral copies and 231 solo ltrs. molecular dating indicates the group originated before the divergence of bears from a common ancestor but is not present in all carnivores. closely related sequences were identified in the giant panda (a ... | 2013 | 23725819 |
| a screening of persistent organohalogenated contaminants in hair of east greenland polar bears. | 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 ... | 2010 | 20800875 |
| the interrelationship of chromosome banding patterns in the giant panda (ailuropoda melanoleuca), hybrid bear (ursus middendorfi x thalarctos maritimus), and other carnivores. | the banded chromosomes of the giant panda (ailuropoda melanoleuca) and a hybrid bear (ursus middendorfi x thalarctos maritimus) have been studied and compared to those of other carnivores. the giant panda shares only a few apparently homologous chromosome arms with the bear (ursidae) and equally few with the lesser panda, ailurus fulgens (procyonidae). chromosomal evidence suggests appropriate placement of the giant panda in a family separate from the uridae and the procyonidae. | 1980 | 7398370 |
| trans-generational and neonatal humoral immune responses in west greenland sledge dogs (canis familiaris) exposed to organohalogenated environmental contaminants. | previous investigations in the arctic have suggested ohc (organohalogen contaminant) induced immune toxic effects on e.g. polar bears (ursus maritimus). we therefore studied the dietary impact from minke whale blubber (balaenoptera acutorostrata), rich in polyunsaturated fatty acids and ohcs, on the humoral immunity of 7 captive west greenland sledge dog (canis familiaris) bitches and their 4 pups constituting a sentinel model species for polar bears. a control group was composed of 8 bitches an ... | 2010 | 20832100 |
| variation in the response of an arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. | polar bears (ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the beaufort, chukchi, and bering seas. in this study, we compared the body size, condition, and recruitment of polar bears captured in the chukchi-bering seas (cs) between two periods (1986-1994 and 2008-2011) when declines in sea ice habitat occurred. additionally, we compared metrics for the cs population 2008-2011 with those of the adjacent sou ... | 2013 | 23913506 |
| biomechanical consequences of rapid evolution in the polar bear lineage. | the polar bear is the only living ursid with a fully carnivorous diet. despite a number of well-documented craniodental adaptations for a diet of seal flesh and blubber, molecular and paleontological data indicate that this morphologically distinct species evolved less than a million years ago from the omnivorous brown bear. to better understand the evolution of this dietary specialization, we used phylogenetic tests to estimate the rate of morphological specialization in polar bears. we then us ... | 2010 | 21079768 |
| a colostrum trypsin inhibitor gene expressed in the cape fur seal mammary gland during lactation. | the colostrum trypsin inhibitor (cti) gene and transcript were cloned from the cape fur seal mammary gland and cti identified by in silico analysis of the pacific walrus and polar bear genomes (order carnivora), and in marine and terrestrial mammals of the orders cetartiodactyla (yak, whales, camel) and perissodactyla (white rhinoceros). unexpectedly, weddell seal cti was predicted to be a pseudogene. cape fur seal cti was expressed in the mammary gland of a pregnant multiparous seal, but not in ... | 2016 | 26639991 |
| temporal trends and future predictions of mercury concentrations in northwest greenland polar bear (ursus maritimus) hair. | hair samples from 117 northwest greenland polar bears (ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafter hg). the sample represented 28 independent years and the aim of the study was to analyze for temporal hg trends. mercury concentrations showed yearly significant increases of 1.6-1.7% (p < 0.0001) from 1892 to 2008 and the two most recent median concentrations from 2006 and 2008 were 23- to 27-fold higher respectively than baseline level from 1300 a.d. in ... | 2011 | 21214235 |
| halogenated phenolic compound determination in plasma and serum by solid phase extraction, dansylation derivatization and liquid chromatography-positive electrospray ionization-tandem quadrupole mass spectrometry. | a robust, sensitive and accurate method was developed for the simultaneous determination in plasma and serum of suite a halogenated phenolic compounds (hpcs) for which several are known to persist in the environment and analytically pure standards are available. namely, 14 congeners of hydroxylated polybrominated diphenyl ethers (oh-pbdes), six congeners of hydroxylated polychlorinated biphenyls (oh-pcbs), pentachlorophenol, pentabromophenol and the flame retardant tetrabromobisphenol a (tbbpa). ... | 2013 | 24210890 |
| comparative analysis of fecal microbiota and intestinal microbial metabolic activity in captive polar bears. | the composition of the intestinal microbiota depends on gut physiology and diet. ursidae possess a simple gastrointestinal system composed of a stomach, small intestine, and indistinct hindgut. this study determined the composition and stability of fecal microbiota of 3 captive polar bears by group-specific quantitative pcr and pcr-dgge (denaturing gradient gel electrophoresis) using the 16s rrna gene as target. intestinal metabolic activity was determined by analysis of short-chain fatty acids ... | 2011 | 21358758 |
| comparative hepatic microsomal biotransformation of selected pbdes, including decabromodiphenyl ether, and decabromodiphenyl ethane flame retardants in arctic marine-feeding mammals. | the present study assessed and compared the oxidative and reductive biotransformation of brominated flame retardants, including established polybrominated diphenyl ethers (pbdes) and emerging decabromodiphenyl ethane (dbdpe) using an in vitro system based on liver microsomes from various arctic marine-feeding mammals: polar bear (ursus maritimus), beluga whale (delphinapterus leucas), and ringed seal (pusa hispida), and in laboratory rat as a mammalian model species. greater depletion of fully b ... | 2011 | 21437940 |
| serologic survey of trichinellosis in wild mammals kept in a mexico city zoo. | a serologic survey of trichinella infection was carried out to determine the prevalence of this parasitosis among wild mammals kept in captivity at the chapultepec zoo. this was prompted by the necropsy finding of a heavy trichinella infection in a canadian polar bear (ursus maritimus) that had been kept at the zoo for more than 11 years. the parasites recovered were identified as t. nativa (t2). a serologic study based on elisa and western blot analysis was performed in serum samples from two p ... | 1996 | 9017871 |
| are terrestrial mammals the source for exposure of polar bear to brucella spp. in alaska? | | 2011 | 21441203 |
| complete mitochondrial genomes of baylisascaris schroederi, baylisascaris ailuri and baylisascaris transfuga from giant panda, red panda and polar bear. | roundworms of the genus baylisascaris are the most common parasitic nematodes of the intestinal tracts of wild mammals, and most of them have significant impacts in veterinary and public health. mitochondrial (mt) genomes provide a foundation for studying epidemiology and ecology of these parasites and therefore may be used to assist in the control of baylisascariasis. here, we determined the complete sequences of mtdnas for baylisascaris schroederi, baylisascaris ailuri and baylisascaris transf ... | 2011 | 21621593 |
| ancient hybridization and an irish origin for the modern polar bear matriline. | polar bears (ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. despite this, little is known about polar bear species history. future conservation strategies would significantly benefit from an understanding of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (u.-áarctos) or their response to previous environmental change. | 2011 | 21737280 |
| persistent chlorinated cyclodiene compounds in ringed seal, polar bear, and human plasma from northern quebec, canada: identification and concentrations of photoheptachlor. | | 1995 | 22200230 |
| toxicokinetics of mercury in blood compartments and hair of fish-fed sled dogs. | abstract: | 2011 | 22152014 |
| blood-based biomarkers of selenium and thyroid status indicate possible adverse biological effects of mercury and polychlorinated biphenyls in southern beaufort sea polar bears. | we examined biomarkers of selenium status (whole blood se; serum se; glutathione peroxidase activity) and thyroid status (concentrations and ratios of thyroxine, t4; tri-iodothyronine, t3; albumin) in polar bears to assess variations among cohorts, and relationships to circulating concentrations of contaminants. concentrations of total mercury (hg) in whole blood were similar among cohorts (prime aged males and females, older animals, ages≥16 years, and young animals, ages 1-5 years; 48.44±35. 8 ... | 2011 | 21903210 |
| studies on the footpads of the polar bear (ursus maritimus) and their possible relevance to accident prevention. | the incidence of slipping accidents is unknown, but accident and emergency departments in the united kingdom probably treat over one million injuries per annum caused by slipping of the feet. many injuries to farm livestock are caused by slipping. previous research led to speculation that some animal species may have developed slip-resistant feet and the polar bear was chosen for a study of adaption to a slippery environment. feet were photographed and a footpad was sectioned and examined by lig ... | 2014 | 4078456 |
| associations between complex ohc mixtures and thyroid and cortisol hormone levels in east greenland polar bears. | the multivariate relationship between hair cortisol, whole blood thyroid hormones, and the complex mixtures of organohalogen contaminant (ohc) levels measured in subcutaneous adipose of 23 east greenland polar bears (eight males and 15 females, all sampled between the years 1999 and 2001) was analyzed using projection to latent structure (pls) regression modeling. in the resulting pls model, most important variables with a negative influence on cortisol levels were particularly bde-99, but also ... | 2012 | 22575327 |
| zebra alphaherpesviruses (ehv-1 and ehv-9): genetic diversity, latency and co-infections. | alphaherpesviruses are highly prevalent in equine populations and co-infections with more than one of these viruses' strains frequently diagnosed. lytic replication and latency with subsequent reactivation, along with new episodes of disease, can be influenced by genetic diversity generated by spontaneous mutation and recombination. latency enhances virus survival by providing an epidemiological strategy for long-term maintenance of divergent strains in animal populations. the alphaherpesviruses ... | 2016 | 27657113 |
| full genome sequences of zebra-borne equine herpesvirus type 1 isolated from zebra, onager and thomson's gazelle. | a strain of equine herpesvirus type 1 (ehv-1) was isolated from zebra. this strain, called "zebra-borne ehv-1", was also isolated from an onager and a gazelle in zoological gardens in u.s.a. the full genome sequences of the 3 strains were determined. they shared 99% identities with each other, while they shared 98% and 95% identities with the horse derived ehv-1 and equine herpesvirus type 9, respectively. sequence data indicated that the ehv-1 isolated from a polar bear in germany is one of the ... | 2014 | 24920546 |
| zebra-borne equine herpesvirus type 1 (ehv-1) infection in non-african captive mammals. | equine herpesvirus type 1 (ehv-1) was detected in an indian rhinoceros (rhinoceros unicornis), which was euthanized because of severe neurological disease. encephalitis was suspected and ehv-1 dna was detected in brain, lung, and spleen tissues. the viral ir6 protein was detected in lung tissues by western blot analysis. phylogenetic analyses of ehv-1 sequences amplified from various tissues was nearly identical to one recently described that resulted in both non-fatal and fatal encephalitis in ... | 2014 | 24440374 |
| sarcocystis caninum and sarcocystis svanai n. spp. (apicomplexa: sarcocystidae) associated with severe myositis and hepatitis in the domestic dog (canis familiaris). | there are several reports of sarcocystis sarcocysts in muscles of dogs, but these species have not been named. additionally, there are two reports of sarcocystis neurona in dogs. here, we propose two new names, sarcocystis caninum, and sarcocystis svanai for sarcocysts associated with clinical muscular sarcocystosis in four domestic dogs (canis familiaris), one each from montana and colorado in the usa, and two from british columbia, canada. only the sarcocyst stage was identified. most of the s ... | 2016 | 25256157 |
| occurrence and genotypic analysis of trichinella species in alaska marine-associated mammals of the bering and chukchi seas. | the zoonotic parasite trichinella is the causative agent of trichinellosis outbreaks in the circumpolar arctic. subsistence communities are particularly prone to trichinellosis due to traditional meat preparation methods and regional presence of a freeze-tolerant trichinella species (trichinella nativa). this study is the first application of a validated artificial digestion method in determining incidence of trichinella sp. in alaskan mammals. infection incidence in pinniped species (erignathus ... | 2014 | 24373515 |
| molecular phylogeny and snp variation of polar bears (ursus maritimus), brown bears (u. arctos), and black bears (u. americanus) derived from genome sequences. | we assessed the relationships of polar bears (ursus maritimus), brown bears (u. arctos), and black bears (u. americanus) with high throughput genomic sequencing data with an average coverage of 25× for each species. a total of 1.4 billion 100-bp paired-end reads were assembled using the polar bear and annotated giant panda (ailuropoda melanoleuca) genome sequences as references. we identified 13.8 million single nucleotide polymorphisms (snp) in the 3 species aligned to the polar bear genome. th ... | 2014 | 24477675 |
| was the giant short-faced bear a hyper-scavenger? a new approach to the dietary study of ursids using dental microwear textures. | dramatic environmental changes associated with global cooling since the late miocene, and the onset of glacial-interglacial cycles in the pleistocene served as a backdrop to the evolutionary radiation of modern bears (family ursidae). these environmental changes likely prompted changes in food availability, and triggered dietary adaptations that served as motive forces in ursid evolution. here, we assess correspondence of dental microwear textures of first and second lower molars with diet in ex ... | 2013 | 24204860 |
| the primary structure of the hemoglobin of spectacled bear (tremarctos ornatus, carnivora). | the complete primary structure of the alpha- and beta-chains of the hemoglobin of spectacled bear (tremarctos ornatus) is presented. following cleavage of the heme-protein link and chain separation by rp-hplc, their amino-acid sequences were determined by edman degradation in liquid- and gas-phase sequenators. the hemoglobin of spectacled bear displays only five amino-acid exchanges to that of polar bear (ursus maritimus, ursinae) and asiatic black bear (ursus tibetanus, ursinae) whereas 8 and 1 ... | 1987 | 3663329 |
| latitudinal variability in the seroprevalence of antibodies against toxoplasma gondii in non-migrant and arctic migratory geese. | toxoplasma gondii is an intracellular coccidian parasite found worldwide and is known to infect virtually all warm-blooded animals. it requires a cat (family felidae) to complete its full life cycle. despite the absence of wild felids on the arctic archipelago of svalbard, t. gondii has been found in resident predators such as the arctic fox and polar bear. it has therefore been suggested that t. gondii may enter this ecosystem via migratory birds. the objective of this study was to identify loc ... | 2012 | 23339847 |
| the significance of the north water polynya to arctic top predators. | the north water polynya (~76°n to 79°n and 70°w to 80°w) is known to be an important habitat for several species of marine mammals and sea birds. for millennia, it has provided the basis for subsistence hunting and human presence in the northernmost part of baffin bay. the abundance of air-breathing top predators also represents a potential source of nutrient cycling that maintains primary production. in this study, aerial surveys conducted in 2009 and 2010 were used for the first time to map th ... | 2012 | 23271401 |
| antidog igg secondary antibody successfully detects igg in a variety of aquatic mammals. | serological tests play an important role in the detection of wildlife diseases. however, while there are many commercial assays and reagents available for domestic species, there is a need to develop efficient serological assays for wildlife. in recent years, marine mammals have represented a wildlife group with emerging infectious diseases, such as influenza, brucellosis, and leptospirosis. however, with the exception of disease-agent-specific assays or functional assays, few reports describe t ... | 2016 | 28080908 |
| chlorinated hydrocarbon contaminants in arctic marine mammals. | by 1976, the presence of chlorinated hydrocarbon contaminants (chcs) had been demonstrated in fur seal (callorhinus ursinus), ringed seal (phoca hispida), hooded seal (cystophora cristata), bearded seal (erignathus barbatus), walrus (obdobenus rosmarus divergens), beluga (delphinapterus leucas), porpoise (phocoena phocoena) and polar bear (ursus maritimus) in various parts of the arctic. in spite of this early interest, very little subsequent research on contaminants in arctic marine mammals was ... | 1994 | 7973601 |
| sequence analysis of three pigmentation genes in the newfoundland population of canis latrans links the golden retriever mc1r variant to white coat color in coyotes. | three genes, mc1r, agouti, and cbd103, interact in a type-switching process that controls much of the pigmentation variation observed in mammals. a deletion in the cbd103 gene is responsible for dominant black color in dogs, while the white-phased black bear ("spirit bear") of british columbia, canada, is the lightest documented color variant caused by a mutation in mc1r. rare all-white animals have recently been discovered in a new northeastern population of the coyote in insular newfoundland a ... | 2013 | 23297074 |
| levels and trends of pbdes and hbcds in the global environment: status at the end of 2012. | in this paper, we have compiled and reviewed the most recent literature, published in print or online from january 2010 to december 2012, relating to the human exposure, environmental distribution, behaviour, fate and concentration time trends of polybrominated diphenyl ether (pbde) and hexabromocyclododecane (hbcd) flame retardants, in order to establish their current trends and priorities for future study. more data are now becoming available for remote areas not previously studied, indian oce ... | 2014 | 24486972 |
| what are the toxicological effects of mercury in arctic biota? | this review critically evaluates the available mercury (hg) data in arctic marine biota and the inuit population against toxicity threshold values. in particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. species whose concentrations exceed threshold values include the polar bears (ursus maritimus), beluga whale (delphinapterus leucas), pilot whale (globicephala melas), hooded seal (cystophora ... | 2013 | 23231888 |
| a protein a/g indirect enzyme-linked immunosorbent assay for the detection of anti-brucella antibodies in arctic wildlife. | a species-independent indirect enzyme-linked immunosorbent assay (ielisa) based on chimeric protein a/g was established for the detection of anti-brucella antibodies in arctic wildlife species and compared to previously established brucellosis serological tests for hooded seals (cystophora cristata), minke whales (balaenoptera acutorostrata), sei whales (balaenoptera borealis), fin whales (balaenoptera physalus), and polar bears (ursus maritimus), as well as bacteriology results for reindeer and ... | 2013 | 23572454 |
| responses of urban crows to con- and hetero-specific alarm calls in predator and non-predator zoo enclosures. | urban animals and birds in particular are able to cope with diverse novel threats in a city environment such as avoiding novel, unfamiliar predators. predator avoidance often includes alarm signals that can be used also by hetero-specifics, which is mainly the case in mixed-species flocks. it can also occur when species do not form flocks but co-occur together. in this study we tested whether urban crows use alarm calls of conspecifics and hetero-specifics (jackdaws, corvus monedula) differently ... | 2017 | 27796660 |
| radiocaesium (137cs) in marine mammals from svalbard, the barents sea and the north greenland sea. | specific activities of the anthropogenic radionuclide, 137cs, were determined in marine mammals from svalbard and the barents and north greenland seas. muscle samples were collected from 12 polar bears, 15 ringed seals, 10 hooded seals, 7 bearded seals, 14 harp seals, one walrus, one white whale and one blue whale in the period 2000-2003. the mean concentrations (+/-sd) of 137cs were: 0.72+/-0.62 bq/kg wet weight (w.w.) for polar bears; 0.49+/-0.07 bq/kg w.w. for ringed seals; 0.25+/-0.10 bq/kg ... | 2006 | 16154620 |
| polychlorinated dibenzo-p-dioxins and dibenzofurans in marine mammals in the canadian north. | polychlorinated dibenzo-p-dioxins (pcdds) and dibenzofurans (pcdfs) were determined in pooled samples of ringed seal (phoca hispida) blubber, beluga (delphinapterus leucas) blubber and polar bear (ursus maritimus) liver and fat from several areas throughout the canadian north and compared to mean pcb and hcb levels in the same samples. all seal samples, and all but one polar bear sample, had detectable 2,3,7,8-tcdd at concentrations ranging from 2 to 37 ng/kg, but tcdd was not found in beluga bl ... | 1990 | 15092247 |
| age and sex composition of seals killed by polar bears in the eastern beaufort sea. | polar bears (ursus maritimus) of the beaufort sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. we collected information on seals killed by polar bears (n=650) and hunting attempts on ringed seal (pusa hispida) lairs (n=1396) observed from a helicopter during polar bear mark-recapture studies in the eastern beaufort sea in spring in 1985-2011. we investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspec ... | 2012 | 22829949 |
| organochlorine burdens in blood of ringed and bearded seals from north-western svalbard. | ringed seal (phoca hispida) and bearded seal (erignathus barbatus) are the main prey of polar bears (ursus maritimus), and information on organochlorines (ocs) in these pinniped species is important to understand the transport, fate and effects of persistent organic pollutants in the arctic ecosystem. thus, ocs were analysed in blood samples of bearded and ringed seals from the coastal ecosystem of the north-western svalbard archipelago (kongsfjorden, 78.55degrees n). the relative contribution o ... | 2001 | 11444300 |
| levels and trends of brominated flame retardants in the arctic. | polybrominated diphenyl ethers (pbdes) containing two to seven bromines are ubiquitous in arctic biotic and abiotic samples (from zooplankton to polar bears (ursus maritimus) and humans; air, soil, sediments). the fully brominated decabromodiphenyl ether (bde-209), hexabromocyclododecane (hbcd), tetrabromobisphenol a (tbbpa) and polybrominated biphenyls (pbbs) are also present in biotic and abiotic samples. spatial trends of pbdes and hbcd in top predators are similar to those seen for polychlor ... | 2006 | 16458344 |
| idiosyncratic responses of grizzly bear habitat to climate change based on projected food resource changes. | climate change vulnerability assessments for species of conservation concern often use species distribution and ecological niche modeling to project changes in habitat. one of many assumptions of these approaches is that food web dependencies are consistent in time and environmental space. species at higher trophic levels that rely on the availability of species at lower trophic levels as food may be sensitive to extinction cascades initiated by changes in the habitat of key food resources. here ... | 2014 | 25154102 |
| application of the luminometric methylation assay to ecological species: tissue quality requirements and a survey of dna methylation levels in animals. | the luminometric methylation assay (luma) measures global dna methylation. luma depends on digestion of dna with methyl-sensitive and methyl-insensitive restriction enzymes, followed by pyrosequencing. until recently, luma has been principally used for biomedical research. here, we use chickens as a model to investigate sample quality issues relating to luma and then apply the method to ecological species. first, we assessed the effect of tissue storage conditions on dna methylation values. this ... | 2014 | 24576185 |
| effects of methylmercury on epigenetic markers in three model species: mink, chicken and yellow perch. | we previously reported that methylmercury (mehg) exposure is associated with dna hypomethylation in the brain stem of male polar bears. here, we conveniently use archived tissues obtained from controlled laboratory exposure studies to look for evidence that mehg can disrupt dna methylation across taxa. brain (cerebrum) tissues from mehg-exposed mink (neovison vison), chicken (gallus gallus) and yellow perch (perca flavescens) were analyzed for total hg levels and global dna methylation. tissues ... | 2013 | 23481557 |
| smallest bitter taste receptor (t2rs) gene repertoire in carnivores. | bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. to investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor (t2r) genes previously found in the genome sequences of two herbivores (cow and horse), two ... | 2013 | 23776004 |
| positive selection in the n-terminal extramembrane domain of lung surfactant protein c (sp-c) in marine mammals. | maximum-likelihood models of codon and amino acid substitution were used to analyze the lung-specific surfactant protein c (sp-c) from terrestrial, semi-aquatic, and diving mammals to identify lineages and amino acid sites under positive selection. site models used the nonsynonymous/synonymous rate ratio (omega) as an indicator of selection pressure. mechanistic models used physicochemical distances between amino acid substitutions to specify nonsynonymous substitution rates. site models strongl ... | 2007 | 17568982 |
| persistent organochlorine pollutants in ringed seals and polar bears collected from northern alaska. | blubber samples from ringed seal (phoca hispida; n = 8) and polar bear subcutaneous fat (ursus maritimus; n = 5) were collected near barrow, alaska in 1996 as part of the alaska marine mammal tissue archival project (ammtap) and retained in the national biomonitoring specimen bank at the national institute of standards and technology in gaithersburg, maryland (usa). the samples were analyzed for a variety of persistent organochlorine pollutants (pops) including polychlorinated biphenyls (pcbs), ... | 2002 | 11885579 |
| [wild mammals of the grand duchy of lithuania in the works of jean-emmanuel gilibert]. | among the many topics of lively scientific work that jean emmanuel gilibert (1741-1814) conducted in grodno and vilnius, an important place is occupied by his observations of wild mammals. royal patronage and care from antoni tyzenhauz, treasurer of the grand duchy of lithuania and the governor of grodno, allowed gilibert to keep and observe wild fauna captured by royal services in royal forests, including białowieża primeval forest. such was an origin of a female bison kept by gilibert in grodn ... | 2015 | 26445747 |
| low density of top predators (seabirds and marine mammals) in the high arctic pack ice. | the at-sea distribution of top predators, seabirds and marine mammals, was determined in the high arctic pack ice on board the icebreaker rv polarstern in july to september 2014. in total, 1,620 transect counts were realised, lasting 30 min each. the five most numerous seabird species represented 74% of the total of 15,150 individuals registered: kittiwake rissa tridactyla, fulmar fulmarus glacialis, puffin fratercula arctica, ross's gull rhodostethia rosea, and little auk alle alle. eight cetac ... | 2016 | 27777810 |
| what to eat now? shifts in polar bear diet during the ice-free season in western hudson bay. | under current climate trends, spring ice breakup in hudson bay is advancing rapidly, leaving polar bears (ursus maritimus) less time to hunt seals during the spring when they accumulate the majority of their annual fat reserves. for this reason, foods that polar bears consume during the ice-free season may become increasingly important in alleviating nutritional stress from lost seal hunting opportunities. defining how the terrestrial diet might have changed since the onset of rapid climate chan ... | 2013 | 24223286 |
| identification of long-chain perfluorinated acids in biota from the canadian arctic. | recently it was discovered that humans and animals from various urban and remote global locations contained a novel class of persistent fluorinated contaminants, the most pervasive of which was perfluorooctane sulfonate (pfos). lower concentrations of perfluorooctanoate, perfluorohexane sulfonate, and heptadecafluorooctane sulfonamide have also been detected in various samples. although longer perfluoroalkyl carboxylates (pfcas) are used in industry and have been detected in fish following a spi ... | 2004 | 14750710 |
| global distribution of perfluorooctane sulfonate in wildlife. | here we report, for the first time, on the global distribution of perfluorooctanesulfonate (pfos), a fluorinated organic contaminant. pfos was measured in the tissues of wildlife, including, fish, birds, and marine mammals. some of the species studied include bald eagles, polar bears, albatrosses, and various species of seals. samples were collected from urbanized areas in north america, especially the great lakes region and coastal marine areas and rivers, and europe. samples were also collecte ... | 2001 | 11348064 |
| an integrated analytical method for determination of polychlorinated aryl methyl sulfone metabolites and polychlorinated hydrocarbon contaminants in biological matrices. | a simple column chromatography method was developed for separation and cleanup in the determination of chlorinated hydrocarbon contaminants and their methyl sulfone (meso2-) metabolites in biological tissues. the method was validated for determination of 11 polychlorinated biphenyls (pcbs), 15 tetra- to heptachloro 3- and 4-meso2-pcbs, 3-meso2-dde, and tris(4-chlorophenyl)-methanol spiked to herring gull egg, smelt, and polar bear liver and adipose tissue using gas chromatography with electron-c ... | 1995 | 8633767 |
| endosulfan, short-chain chlorinated paraffins (sccps) and octachlorostyrene in wildlife from greenland: levels, trends and methodological challenges. | besides globally banned "legacy" persistent organic pollutants, other compounds might be present in arctic wildlife, for which regulation was introduced recently (the insecticide endosulfan), is considered (short-chain chlorinated paraffins, sccps) or does not exist (octachlorostyrene, ocs, a byproduct of manufacturing and combustion processes involving chlorine). the purpose of this study was to analyze the time trend of endosulfan (1986-2012) in ringed seals and to address the levels of sccps ... | 2017 | 28667423 |
| novel brominated flame retardants and dechlorane plus in greenland air and biota. | following the ban of polybrominated diphenyl ethers, other halogenated flame retardants (frs) might be used increasingly. this study has analyzed hexabromocyclododecane (hbcd), 1,2-bis(2,4,6-tribromophenoxy)-ethane (btbpe), 2,3-dibromopropyl-2,4,6-tribromophenyl ether (dpte) and dechloraneplus (dp) in greenland air over the course of a year. moreover, btbpe, dpte, dp, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (tbb), bis(2-ethylhexyl) tetrabromophthalate (tbph) and decabromodiphenylethane (dbdpe) w ... | 2015 | 25463724 |
| comparative hepatic in vitro depletion and metabolite formation of major perfluorooctane sulfonate precursors in arctic polar bear, beluga whale, and ringed seal. | perfluorooctane sulfonate (pfos) has been reported to be among the most concentrated persistent organic pollutants in arctic marine wildlife. the present study examined the in vitro depletion of major pfos precursors, n-ethyl-perfluorooctane sulfonamide (n-etfosa) and perfluorooctane sulfonamide (fosa), as well as metabolite formation using an assay based on enzymatically viable liver microsomes for three top arctic marine mammalian predators, polar bear (ursus maritimus), beluga whale (delphina ... | 2014 | 25048910 |
| assessment of neurotoxic effects of mercury in beluga whales (delphinapterus leucas), ringed seals (pusa hispida), and polar bears (ursus maritimus) from the canadian arctic. | marine mammals are indicator species of the arctic ecosystem and an integral component of the traditional inuit diet. the potential neurotoxic effects of increased mercury (hg) in beluga whales (delphinapterus leucas), ringed seals (pusa hispida), and polar bears (ursus maritimus) are not clear. we assessed the risk of hg-associated neurotoxicity to these species by comparing their brain hg concentrations with threshold concentrations for toxic endpoints detected in laboratory animals and field ... | 2015 | 24958011 |
| accumulation of vitamin a in the hepatic stellate cell of arctic top predators. | we performed a systematic characterization of the hepatic vitamin a storage in mammals and birds of the svalbard archipelago and greenland. the liver of top predators, including polar bear, arctic fox, bearded seal, and glaucous gull, contained about 10-20 times more vitamin a than the liver of all other arctic animals studied, as well as their genetically related continental top predators. the values are also high compared to normal human and experimental animals like mouse and rat. this massiv ... | 2012 | 22907891 |
| the evolution of arctic marine mammals. | this review deals only with the evolutionary history of core arctic marine mammals: polar bear (ursus maritimus), walrus (odobenus rosmarus), bearded seal (erignathus barbatus), harp seal (pagophilus groenlandica), ringed seal (phoca hispida), bowhead whale (balaena mysticetus), white whale (delphinapterus leucas), and narwhal (monodon monoceras). sections on the evolutionary background of pinnipeds and whales help to provide a better perspective on these core species. polar bears stemmed from b ... | 2008 | 18494361 |
| trophic relationships in an arctic food web and implications for trace metal transfer. | 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 (delta13c) and nitrogen (delta15n) 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 ... | 2006 | 16387350 |
| ecotoxicological risk assessment of environmental pollutants in the arctic. | concentrations of such persistent organic pollutants (pops) as polychlorinated biphenyls (pcbs) are high in certain arctic animal species. the polar bear, arctic fox, and glaucous gull may be exposed to pcb levels above lowest-observed-adverse-effect-level (loael) values for adverse effects on reproduction in mammals and birds. however, the dioxin-like congeners seem to be major contributors to the reproductive effects of pcbs and the relative concentrations of these congeners are low in polar b ... | 2000 | 10720719 |
| analysis of zp1 gene reveals differences in zona pellucida composition in carnivores. | the zona pellucida (zp) is an extracellular envelope that surrounds mammalian oocytes. this coat participates in the interaction between gametes, induction of the acrosome reaction, block of polyspermy and protection of the oviductal embryo. previous studies suggested that carnivore zp was formed by three glycoproteins (zp2, zp3 and zp4), with zp1 being a pseudogene. however, a recent study in the cat found that all four proteins were expressed. in the present study, in silico and molecular anal ... | 2017 | 28679462 |
| recent progress on our understanding of the biological effects of mercury in fish and wildlife in the canadian arctic. | this review summarizes our current state of knowledge regarding the potential biological effects of mercury (hg) exposure on fish and wildlife in the canadian arctic. although hg in most freshwater fish from northern canada was not sufficiently elevated to be of concern, a few lakes in the northwest territories and nunavut contained fish of certain species (e.g. northern pike, arctic char) whose muscle hg concentrations exceeded an estimated threshold range (0.5-1.0 μg g(-1) wet weight) within w ... | 2015 | 24935263 |
| polychloronaphthalenes and other dioxin-like compounds in arctic and antarctic marine food webs. | here we report accumulation patterns of polychlorinated naphthalenes (pcns), polychlorinated dibenzo-p-dioxins (pcdds), polychlorinated dibenzofurans (pcdfs), polychlorinated biphenyls (pcbs), and pesticides (hcb, p,p'dde) in polar organisms (polar bear from alaskan arctic and krill, sharp-spined notothen, crocodile icefish, antarctic silverfish, adélie penguin, south polar skua, and weddell seal from the ross sea, antarctica). pcns, found in most of the samples, ranged from 1.5 pg/g in krill to ... | 2002 | 12214639 |
| polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in polar bear, penguin and south polar skua. | concentrations of 2378-substituted polychlorinated dibenzo-p-dioxins (pcdds), dibenzofurans (dfs) and non- and mono-ortho-substituted polychlorinated biphenyls (dioxin-like pcbs) were measured in livers of polar bears from the alaskan arctic and in eggs of adelie penguin and south polar skua and weddell seal liver, fish and krill from antarctica. this is one of the first reports to document the concentrations of pcdds/dfs in polar bear livers from alaska, and in penguin and skua eggs from antarc ... | 2002 | 12152823 |
| increasing nest predation will be insufficient to maintain polar bear body condition in the face of sea ice loss. | climate change can influence interspecific interactions by differentially affecting species-specific phenology. in seasonal ice environments, there is evidence that polar bear predation of arctic bird eggs is increasing because of earlier sea ice breakup, which forces polar bears into nearshore terrestrial environments where arctic birds are nesting. because polar bears can consume a large number of nests before becoming satiated, and because they can swim between island colonies, they could hav ... | 2017 | 27614094 |
| longer ice-free seasons increase the risk of nest depredation by polar bears for colonial breeding birds in the canadian arctic. | northern polar regions have warmed more than other parts of the globe potentially amplifying the effects of climate change on biological communities. ice-free seasons are becoming longer in many areas, which has reduced the time available to polar bears (ursus maritimus) to hunt for seals and hampered bears' ability to meet their energetic demands. in this study, we examined polar bears' use of an ancillary prey resource, eggs of colonial nesting birds, in relation to diminishing sea ice coverag ... | 2014 | 24500172 |
| frequency of consumption of foods and beverages by inuvialuit adults in northwest territories, arctic canada. | limited data exist regarding nutrient intakes and overall dietary quality in canadian arctic populations. this cross-sectional study determined the frequency of consumption of traditional meats (e.g. caribou, polar bear, seal, char and whale) and non-traditional store-bought foods including non-traditional meats (e.g. beef, pork and chicken), grains, dairy, fruits, vegetables and non-nutrient dense foods (nndfs) (e.g. butter, chocolate, chips, candy and pop) by inuvialuit adults (175 women, mean ... | 2012 | 22475024 |
| a rapid analytical method to quantify complex organohalogen contaminant mixtures in large samples of high lipid mammalian tissues. | in vitro investigations of the health impact of individual chemical compounds have traditionally been used in risk assessments. however, humans and wildlife are exposed to a plethora of potentially harmful chemicals, including organohalogen contaminants (ohcs). an alternative exposure approach to individual or simple mixtures of synthetic ohcs is to isolate the complex mixture present in free-ranging wildlife, often non-destructively sampled from lipid rich adipose. high concentration stock volu ... | 2017 | 28273531 |
| habitat degradation affects the summer activity of polar bears. | understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. although climate change is significantly impacting species' distributions, few studies have examined associated changes in behavior. polar bear (ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. we examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using ... | 2017 | 28247129 |
| dietary habits of polar bears in foxe basin, canada: possible evidence of a trophic regime shift mediated by a new top predator. | polar bear (ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. in the foxe basin region of nunavut, canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. we used fatty acid analysis to examine polar bear feeding habits in foxe basin and thus potentially identify ... | 2016 | 27547372 |
| rapid environmental change drives increased land use by an arctic marine predator. | in the arctic ocean's southern beaufort sea (sb), the length of the sea ice melt season (i.e., period between the onset of sea ice break-up in summer and freeze-up in fall) has increased substantially since the late 1990s. historically, polar bears (ursus maritimus) of the sb have mostly remained on the sea ice year-round (except for those that came ashore to den), but recent changes in the extent and phenology of sea ice habitat have coincided with evidence that use of terrestrial habitat is in ... | 2016 | 27249673 |
| spatial and temporal trends and effects of contaminants in the canadian arctic marine ecosystem: a review. | recent studies have added substantially to our knowledge of spatial and temporal trends of persistent organic pollutants and heavy metals in the canadian arctic marine ecosystem. this paper reviews the current state of knowledge of contaminants in marine biota in the canadian arctic and where possible, discusses biological effects. the geographic coverage of information on contaminants such as persistent organochlorines (ocs) (pcbs, ddt- and chlordane-related compounds, hexachlorocyclohexanes, t ... | 1999 | 10466228 |
| ad-libs: inferring ancestry across hybrid genomes using low-coverage sequence data. | inferring the ancestry of each region of admixed individuals' genomes is useful in studies ranging from disease gene mapping to speciation genetics. current methods require high-coverage genotype data and phased reference panels, and are therefore inappropriate for many data sets. we present a software application, ad-libs, that uses a hidden markov model to infer ancestry across hybrid genomes without requiring variant calling or phasing. this approach is useful for non-model organisms and in c ... | 2017 | 28376731 |
| accumulation and transfer of contaminants in killer whales (orcinus orca) from norway: indications for contaminant metabolism. | blubber tissue of one subadult and eight male adult killer whales was sampled in northern norway in order to assess the degree and type of contaminant exposure and transfer in the herring-killer whale link of the marine food web. a comprehensive selection of contaminants was targeted, with special attention to toxaphenes and polybrominated diphenyl ethers (pbdes). in addition to assessing exposure and food chain transfer, selective accumulation and metabolism issues also were addressed. average ... | 2007 | 17702329 |
| development and application of an ultratrace method for speciation of organotin compounds in cryogenically archived and homogenized biological materials. | an accurate, ultra-sensitive and robust method for speciation of mono, di, and tributyltin (mbt, dbt, and tbt) by speciated isotope-dilution gas chromatography-inductively coupled plasma-mass spectrometry (sid-gc-icpms) has been developed for quantification of butyltin concentrations in cryogenic biological materials maintained in an uninterrupted cryo-chain from storage conditions through homogenization and bottling. the method significantly reduces the detection limits, to the low pg g(-1) lev ... | 2007 | 17287930 |
| congener-specific accumulation and food chain transfer of polybrominated diphenyl ethers in two arctic food chains. | congener-specific accumulation and prey to predator transfer of 22 polybrominated diphenyl ethers (pbdes) were assessed in polar cod, ringed seal, polar bear, and beluga whale. although the concentrations found were relatively low, these results show that pbdes have reached the arctic. pbde congeners 47, 99, and 100 were dominant in all species studied. the pattern in ringed seal was somewhat simpler than in polar cod, with pbde 47 accounting for more than 90% of the total pbdes. in contrast, be ... | 2004 | 15074673 |
| effects of polar bear and killer whale derived contaminant cocktails on marine mammal immunity. | most controlled toxicity studies use single chemical exposures that do not represent the real world situation of complex mixtures of known and unknown natural and anthropogenic substances. in the present study, complex contaminant cocktails derived from the blubber of polar bears (pb; ursus maritimus) and killer whales (kw; orcinus orca) were used for in vitro concentration-response experiments with pb, cetacean and seal spp. immune cells to evaluate the effect of realistic contaminant mixtures ... | 2017 | 28876915 |
| marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids. | the national institute of standards and technology (nist) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. standard reference material (srm) 1945 organics in whale blubber was recertified for polychlorinated biphenyl (pcb) congeners, organochlorine pesticides, and polybrominated diphenyl ether (pbde) congeners. srm 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congene ... | 2010 | 20238106 |
| global change effects on the long-term feeding ecology and contaminant exposures of east greenland polar bears. | rapid climate changes are occurring in the arctic, with substantial repercussions for arctic ecosystems. it is challenging to assess ecosystem changes in remote polar environments, but one successful approach has entailed monitoring the diets of upper trophic level consumers. quantitative fatty acid signature analysis (qfasa) and fatty acid carbon isotope (δ(13) c-fa) patterns were used to assess diets of east greenland (eg) polar bears (ursus maritimus) (n = 310) over the past three decades. qf ... | 2013 | 23640921 |
| quantifying the sensitivity of arctic marine mammals to climate-induced habitat change. | we review seven arctic and four subarctic marine mammal species, their habitat requirements, and evidence for biological and demographic responses to climate change. we then describe a pan-arctic quantitative index of species sensitivity to climate change based on population size, geographic range, habitat specificity, diet diversity, migration, site fidelity, sensitivity to changes in sea ice, sensitivity to changes in the trophic web, and maximum population growth potential (r(max)). the index ... | 2008 | 18494365 |
| arctic marine ecosystem contamination. | the current state of knowledge of levels, spatial and temporal trends of contaminants in the arctic marine ecosystem varies greatly among pollutants and among environmental compartments. levels of polychlorinated biphenyls (pcbs), organochlorine (oc) pesticides and some heavy metals such as mercury and lead, in arctic marine mammals and fish are relatively well documented because of the need for comparisons with biota in more polluted environments and interest in the contamination of native diet ... | 1992 | 1514106 |
| new support for polar bears and tigers. | | 2010 | 21210537 |
| observation of emerging per- and polyfluoroalkyl substances (pfass) in greenland marine mammals. | the present pilot study examined emerging per- and polyfluoroalkyl substances (pfass), i.e., a suite of short chain perfluoroalkyl acids (pfaas), pfaa precursors and replacement chemicals, and legacy pfass (long chain length pfaas) in livers from ringed seals, polar bears and, for the first time, killer whales from east greenland collected in 2012-2013. among the emerging pfass, perfluorobutanesulfonic acid (pfbs) and f-53b (a chlorinated polyfluorinated ether sulfonic acid) were detected in arc ... | 2016 | 26610298 |
| genome-wide search identifies 1.9 mb from the polar bear y chromosome for evolutionary analyses. | the male-inherited y chromosome is the major haploid fraction of the mammalian genome, rendering y-linked sequences an indispensable resource for evolutionary research. however, despite recent large-scale genome sequencing approaches, only a handful of y chromosome sequences have been characterized to date, mainly in model organisms. using polar bear (ursus maritimus) genomes, we compare two different in silico approaches to identify y-linked sequences: 1) similarity to known y-linked genes and ... | 2015 | 26019166 |