parasite-related lesions in a bearded seal, erignathus barbatus.a free-ranging adult male bearded seal (erignathus barbatus) killed by polar bears was salvaged and examined at necropsy. significant findings included diffuse intrahepatic bile duct fibrosis and chronic cholangitis; multiple nodules of chronic fibrosing pancreatitis; and gastric ulcers. trematode eggs (family campulidae) were found in the pancreatic nodules. these eggs and the trematodes that produced them probably caused the pancreatic and liver lesions. phocanema decipiens and contracaecum os ...1979113564
[helminth fauna of bering sea pinnipeds from karaginskiy bay].the helminthological investigations were conducted from may 6 to may 28, 1972 in the karaginsk gulf of the bering sea. the helminths were collected from 124 specimens of phoca vitulina largha, 9 specimens of erignathus barbatus nauticus, 9 specimens of pusa hispida krascheninnikovi and 9 specimens of histriophoca fasciata. in all, 23 species, 2 immature and 1 larval form of helminths were recorded. the data are given on the localization of helminths, intensity and extensity of their invasion, pa ...1976958725
genetic evidence for three species within pseudoterranova decipiens (nematoda, ascaridida, ascaridoidea) in the north atlantic and norwegian and barents seas.genetic variation of 1017 specimens of codworm, pseudoterranova decipiens, collected from fish and seals at 23 sampling locations in the north atlantic and norwegian and barents seas, was analysed on the basis of 16 enzyme loci. three reproductively isolated species, provisionally designated p. decipiens a, b and c, were detected, showing distinct alleles at the following loci: mdh-1, 6pgdh, np, pgm, est-2 (between species a and b); mdh-3, 6pgdh, np, sod-1, adk, pgm, est-2, mpi (between a and c) ...19911869354
twenty years of trace metal analyses of marine mammals in alaska: evaluation and summation.the compilation of existing data on contaminants in the marine food chain is essential in addressing concerns regarding the magnitude of potential human exposures and in the evaluation of subsistence food safety. this paper presents a summary of studies on trace metals in tissues of alaska marine mammals from the 1970s to the present, along with derived mean tissue trace metal concentrations. the derived mean can serve as a norm against which future monitoring results may be compared, and may be ...199810093345
evidence of brucella infection in marine mammals in the north atlantic ocean.between 1983 and 1996 a total of 1386 samples of serum were taken from four species of seal and three species of whale in the waters west of iceland, the area of pack-ice north-west of jan mayen, the northern coast of norway and the kola peninsula, the waters west of svalbard, and the barents sea; they were tested for the presence of anti-brucella antibodies with an indirect elisa (protein g conjugate). the positive sera were re-tested with classical brucellosis serological tests, such as the se ...199910378290
the occurrence and ecology of trichinella in marine mammals.trichinella in marine mammals has a circumpolar arctic distribution and a narrow range of host species. it is commonly found in polar bears (ursus maritimus), and increasingly in walruses (odobenus rosmarus) where it presents a significant zoonotic hazard. this has resulted in the implementation of food safety programs in some arctic communities to test harvested walrus meat for trichinella larvae prior to consumption. trichinella has been reported infrequently in bearded seals (erignathus barba ...200011099845
toxoplasma gondii, neospora caninum, sarcocystis neurona, and sarcocystis canis-like infections in marine mammals.toxoplasma gondii, neospora caninum, sarcocystis neurona, and s. canis are related protozoans that can cause mortality in many species of domestic and wild animals. recently, t. gondii and s. neurona were recognized to cause encephalitis in marine mammals. as yet, there is no report of natural exposure of n. caninum in marine mammals. in the present study, antibodies to t. gondii and n. caninum were assayed in sera of several species of marine mammals. for t. gondii, sera were diluted 1:25, 1:50 ...200314580799
are liver and renal lesions in east greenland polar bears (ursus maritimus) associated with high mercury levels?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.200717439647
seroepidemiology of toxoplasma gondii and neospora caninum in seals around hokkaido, japan.serological analysis was performed to detect toxoplasma gondii and neospora caninum infection in seals in hokkaido. serum samples were collected from 322 kuril harbor seals (phoca vitulina stejnegeri) at nosappu, akkeshi and erimo, from 46 spotted seals (p. largha) at nosappu, erimo, yagishiri island, hamamasu and syakotan, and from 4 ribbon seals (p. fasciata) and a bearded seal (erignathus barbatus) at nosappu between 1998 and 2006. recombinant surface antigen of t. gondii (sag2t) and n. canin ...200717485927
137cs and 210po in pacific walrus and bearded seal from st. lawrence island, alaska.the activity concentration of cesium-137 ((137)cs) and naturally-occurring polonium-210 ((210)po) were measured in the muscle tissue, kidney and liver of pacific walrus (odobenus rosmarus divergens) and bearded seal (erignathus barbatus) collected by native hunters from the bering sea during may 1996. the mean (137)cs concentrations in muscle, liver and kidney of pacific walrus were 0.07, 0.09 and 0.07 bq kg(-1) (n=5, wet weight), respectively, and 0.17, 0.10, and 0.17 bq kg(-1) (n=2, wet weight ...200818371988
regional variability in food availability for arctic marine mammals.this review provides an overview of prey preferences of seven core arctic marine mammal species (amm) and four non-core species on a pan-arctic scale with regional examples. arctic marine mammal species exploit prey resources close to the sea ice, in the water column, and at the sea floor, including lipid-rich pelagic and benthic crustaceans and pelagic and ice-associated schooling fishes such as capelin and arctic cod. prey preferred by individual species range from cephalopods and benthic biva ...200818494364
arctic marine mammals and climate change: impacts and resilience.evolutionary selection has refined the life histories of seven species (three cetacean [narwhal, beluga, and bowhead whales], three pinniped [walrus, ringed, and bearded seals], and the polar bear) to spatial and temporal domains influenced by the seasonal extremes and variability of sea ice, temperature, and day length that define the arctic. recent changes in arctic climate may challenge the adaptive capability of these species. nine other species (five cetacean [fin, humpback, minke, gray, an ...200818494369
viral and bacterial serology of six free-ranging bearded seals erignathus barbatus.serum or heparinized plasma samples were obtained from 3 male (2 adult and 1 weaned calf) and 3 adult female free-ranging bearded seals erignathus barbatus in may of 1994, 1995, or 1996. blood samples were obtained from animals taken in subsistence hunts near st. lawrence island, alaska and screened for antibodies to a suite of bacteria and viruses potentially pathogenic for pinnipeds and/or humans. no samples had detectable antibodies to brucella spp., phocine distemper virus, influenza a virus ...200818828565
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 ...201223271401
prevalence of zoonotic anisakid nematodes in inuit-harvested fish and mammals from the eastern canadian arctic.human anisakidosis is a recognized arctic zoonosis that is directly related to the consumption of traditional inuit foods, particularly raw fish. the epidemiology of infections with the zoonotic anisakid nematodes anisakis simplex and pseudoterranova decipiens was investigated from august 2007 to july 2009 in inuit-harvested fish and marine mammals from inuit regions of nunavik, nunavut, and nunatsiavut, canada. fish were tested for anisakid larvae using the pepsin-hcl digestion method, and the ...201222957974
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 ...201424373515
chlorinated hydrocarbon contaminants in arctic marine 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 ...19947973601
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 ...200818494361
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 ...200616154620
feeding kinematics, suction and hydraulic jetting capabilities in bearded seals (erignathus barbatus).feeding kinematics, suction and hydraulic jetting capabilities of bearded seals (erignathus barbatus) were characterized during controlled feeding trials. feeding trials were conducted both on land and in water, and allowed a choice between suction and biting, but food was also presented that could be ingested by suction alone. four feeding phases, preparatory, jaw opening, hyoid depression and jaw closing were observed; the mean feeding cycle duration was 0.54+/-0.22 s, regardless of feeding mo ...200818281332
effect of climatic warming on the pacific walrus, and potential modification of its helminth fauna.the decreasing extent of sea-ice in the arctic basin as a consequence of climatic warming is modifying the behavior and diets of pagophilic pinnipeds, including the pacific walrus, odobenus rosmarus divergens illiger, the species emphasized here. mammals such as the walrus and bearded seal, erignathus barbatus (erxleben), cannot remain associated with the sea-ice, and continue to feed on their usual diet of benthic invertebrates inhabiting coastal waters to a depth of approximately 100 m, when t ...200718163371
seal and whale meat: two newly recognized food allergies.alaska's marine mammals compose a large portion of the diet of indigenous coastal alaskan people. bowhead whales (balaena mysticetus) and bearded seals (erignathus barbatus), inhabitants of the bering and beaufort seas along alaska's western and northern coasts, are 2 of the most important subsistence species, serving as major food sources to the native population.200717225727
volatile siloxanes in the european arctic: assessment of sources and spatial distribution.the purpose of this study was to investigate presence and potential accumulation of cyclic volatile methyl siloxanes (cvms) in the arctic environment. octamethylcyclotetrasiloxane (d4), decamethylcyclopentasiloxane (d5), and dodecamethylcyclohexasiloxane (d6) were analyzed in sediment, zooplankton, atlantic cod (gadus morhua), shorthorn sculpin (myxocephalus scorpius), and bearded seal (erignathus barbatus) collected from the svalbard archipelago within the european arctic in july 2009. highest ...201020836489
energy intake and utilisation by nursing bearded seal (erignathus barbatus) pups from svalbard, this study we measure energy intake via milk in nursing bearded seal (erignathus barbatus) pups and determine how this energy is allocated into metabolism and storage of new tissues. this was accomplished using longitudinal mass gain records and the doubly labelled water technique on nursing pups in combination with cross-sectional data on changes in milk composition from bearded seal mothers. the pups (n = 3) were all less than a week old at the start of the experiments. pups gained 3.3 +/- ...19968956501
[diphyllobothrium skriabini sp. n. (cestoda: diphyllobothriidae)--a parasite of the bearded seal (erignathus barbatus erx.)].a new species of cestodes is described from the intestine of erignathus barbatus erx. the species differs from the other members of the genus in the shape of scolex, the character of strobilation and in many other characters. data are given on its morphological variability in different waters: the greenland and east siberian seas, the bering strait. two subspecies, d. s. europeum and d. s. asiaticum, are erected. the species is named in honour of professor a. s. skriabin, one of the most outstan ...20128474767
[growth in length of the bearded seal (erignathus barbatus, erxleben 1777) following benjaminsen (1973) data].length data for almost 200 bearded seals around svalbard and in the barents sea gained in 1968 and 1970 by benjaminsen are taken as a basis for mathematical considerations. age has been deduced from annual bandings of teeth in the upper jaw and in the claws. in the original treatment a curve for length growth has been drawn by eye despite severe scattering of the basic data. the mathematical methods now available allow approximations by growth functions and lead to a surprising agreement for 5 f ...19863826646
nasal mites (acari:halarachnidae) in the spotted seal, phoca largha pallas, and other pinnipeds of alaskan waters.the nasal passages of 349 pinnipeds of seven species were examined for halarachnid mites. each of seven steller sea lions (eumetopias jubatus), 75 of 99 harbor seals (phoca vitulina), and four of 71 spotted seals (p. largha) were infected, but none of 28 walruses (odobenus rosmarus), 43 ringed seals (phoca hispida), 58 ribbon seals (p. fasciata), and 43 bearded seals (erignathus barbatus) was infected. the sea lions harbored orthohalarachne attenuata (banks, 1910) and o. diminuata (doetschman, 1 ...19827097872
giardia duodenalis and cryptosporidium spp. in the intestinal contents of ringed seals (phoca hispida) and bearded seals (erignathus barbatus) in nunavik, quebec, canada.the prevalence of giardia duodenalis and cryptosporidium spp. was determined for ringed and bearded seals harvested for food in the nunavik region in northern quebec, canada. flow cytometric results demonstrated that g. duodenalis was present in the intestinal contents of 80% of the ringed seals and 75% of the bearded seals tested, while cryptosporidium spp. were present in 9% of the ringed seals and none of the bearded seals. prevalence of both parasites was highest in animals less than 1 yr of ...200818576814
concentrations of persistent organochlorine contaminants in bowhead whale tissues and other biota from northern alaska: implications for human exposure from a subsistence diet.bowhead whale (balaena mysticetus; n = 5) blubber, liver, muscle, kidney, heart, diaphragm, tongue, and uncooked maktak (bowhead whale epidermis and blubber) were collected during subsistence hunts at barrow, ak, usa (1997-1999) to measure concentrations of persistent organochlorine contaminants (ocs). the exposure of humans to ocs via bowhead whales and other biota [fish, ringed (phoca hispida) and bearded seals (erignathus barbatus), and beluga whale (delphinapterus leucas)] as part of a subsi ...200515910787
some heavy metals, essential elements, and chlorinated hydrocarbons in polar bear (ursus maritimus) at svalbard.during the period 1978-1989, samples of liver, kidney and subcutaneous fat from 24 polar bears, ursus maritimus, from svalbard were analysed for mercury, cadmium, lead, copper, zinc, selenium, arsenic, hcb, dde, pcbs (as aroclor 1260 or phenoclor dp6). in a selected number of liver (seven) and fat (three) samples, the composition of individual pcb congeners was studied by comparison with 23 individual pcb congeners (iupac nos 28, 52, 74, 101, 99, 110, 149, 118, 114, 105, 153, 141, 138, 187, 128, ...199215091977
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 ...199910466228
enantiomer-specific biomagnification of alpha-hexachlorocyclohexane and selected chiral chlordane-related compounds within an arctic marine food web.concentrations of achiral and chiral organochlorine contaminants (ocs), including hexachlorocyclohexane isomers (hch), chlordane congeners (cis- and trans-chlordane, cis- and trans-nonachlor, mc5, mc7, and u82), and related metabolites (oxychlordane [oxy] and heptachlor exo-epoxide [hepx]), were quantified in seawater (100 l; n = 6) and biota from the coastal beaufort-chukchi seas food web near barrow (ak, usa). the biota included zooplankton (calanus spp.; n = 5), fish species such as arctic co ...200314552014
trophic transfer of persistent organochlorine contaminants (ocs) within an arctic marine food web from the southern beaufort-chukchi seas.stable isotope values (13c, 15n) and concentrations of persistent organochlorine contaminants (ocs) were determined to evaluate the near-shore marine trophic status of biota and biomagnification of ocs from the southern beaufort-chukchi seas (1999-2000) near barrow, ak. the biota examined included zooplankton (calanus spp.), fish species such as arctic cod (boreogadus saida), arctic char (salvelinus alpinus), pink salmon (oncorhynchus gorbuscha), and fourhorn sculpin (myoxocephalus quadricornis) ...200312758030
nuclear deviation in hepatic parenchymal cells on sinusoidal surfaces in arctic normal rat and human, most of the nuclei of hepatic parenchymal cells are centrally located in the cytoplasm. however, it is reported that the nuclei of hepatic parenchymal cells are situated at a deviated position on sinusoidal surfaces under pathological situations such as chronic hepatitis, hepatocellular carcinoma, adenomatous hyperplasia, or regeneration. during a study on the mechanism of extreme vitamin a-accumulation in hepatic stellate cells of arctic animals including polar bears, a ...200111482455
concentrations of chlorinated hydrocarbons and trace elements in marine mammal tissues archived in the u.s. national biomonitoring specimen bank.the u.s. national biomonitoring specimen bank (nbsb) provides for the long term storage of well documented and preserved specimens representing several types of environmental matrices. a major part of this inventory consists of marine mammal tissues (e.g., blubber, liver, kidney, and muscle). within the nbsb selected specimens are periodically analyzed for chlorinated hydrocarbons and trace elements. although only 20% of the 560 marine mammal specimens in the nbsb have been analyzed, the databas ...19979159906
resource partitioning between pacific walruses and bearded seals in the alaska arctic and sub-arctic.climate-mediated changes in the phenology of arctic sea ice and primary production may alter benthic food webs that sustain populations of pacific walruses (odobenus rosmarus divergens) and bearded seals (erignathus barbatus). interspecific resource competition could place an additional strain on ice-associated marine mammals already facing loss of sea ice habitat. using fatty acid (fa) profiles, fa trophic markers, and fa stable carbon isotope analyses, we found that walruses and bearded seals ...201728550467
activity concentration measurements of selected radionuclides in seals from canadian arctic.the activity concentrations of naturally occurring radionuclides (such as (226)ra, (210)pb and (210)po) and long lived (137)cs were measured in a total of 119 tissue samples (43 blubber, 43 liver, and 33 muscle samples) from 40 ringed seals and 4 bearded seals collected in the arviat area of canada during the fall of 2014. activity concentration of (210)po was measured in all seal liver and muscle samples individually. the average (210)po activity concentrations were 25 ± 7.6 bq/kg fresh weight ...201728068555
heavy metals and essential elements in livers of the polar bear (ursus maritimus) in the canadian arctic.polar bear (ursus maritimus) livers (67) from six management zones in the western and central canadian arctic were analysed for 22 elements. several, ba, be, co, mo, ti, v and zr, were near the detection limit in all cases. baseline data were obtained for the remaining elements, ag, as, ca, cd, cu, fe, hg, k, mg, mn, na, p, se, sr and zn. no statistically significant effect of age, sex or geographical location was found for any of the elements, except cd, hg and se, for which age and geographica ...19863961478
on the ecology and distribution of pseudoterranova decipiens c (nematoda: anisakidae) in an intermediate host, hippoglossoides platessoides, in northern norwegian waters.the distribution of pseudoterranova decipiens c helps demonstrate the ecological basis of this genetically defined sibling species. in northern norwegian waters the major fish intermediate host is hippoglossoides platessoides. overall prevalence, mean intensity and intensity range in h. platessoides were 15%, 16.5 and 1-165, respectively. outside the range of its only known definitive host, the seal erignathus barbatus, the parasite was not found in the same intermediate host.19921587684
levels of heavy metals in seals of lake ladoga and the white sea.between 1990 and 1993 samples of hair, liver, kidney and muscle were collected from 28 ringed seals from lake ladoga, phoca hispida ladogensis, 20 ringed seals, phoca hispida hispida, and three bearded seals, erignathus barbatus, from the white sea for heavy-metal residue analyses in tissues. the concentration of hg, cd, pb, cu, ni and zn were determined by atomic absorption spectrometry (aas). the samples of hair and liver contained the highest mean levels of the elements analysed and the muscl ...19979394478
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 ...200111444300
precocial diving and patent foramen ovale in bearded seal (erignathus barbatus) this study we used a doppler ultrasonic device, in combination with a sonographic contrast medium, to test whether free-living bearded seal (erignathus barbatus) pups have a closed (anatomically or functionally) foramen ovale. a total of 17 examinations were performed on 12 individual pups with a body mass range of 29-103 kg (0-21 days old). these examinations showed that young bearded seal pups dive with a patent foramen ovale (pfo), and that this structure starts to close, at least function ...200212444470
characterization of oligosaccharides in milk of bearded seal (erignathus barbatus).carbohydrates were extracted from milk of a bearded seal, erignathus barbatus (family phocidae). free neutral oligosaccharides were separated by gel filtration, anion-exchange chromatography and preparative thin layer chromatography, while free acidic oligosaccharides were separated by gel filtration and then purified by ion exchange chromatography, gel filtration and high performance liquid chromatography. oligosaccharide structures were determined by 1h-nmr spectroscopy. the structures of the ...200415142532
traditional diet and environmental contaminants in coastal chukotka ii: legacy pops.the article is the second in the series of four that present the results of a study on environmental contaminants in coastal chukotka, conducted in the context of a multi-disciplinary investigation of indigenous foodways in the region. the article presents the results of the analysis of legacy persistent organic pollutants (pops) found in the samples of locally harvested food and indoor matters, collected in 2016 in coastal chukotka. temporal trends and circumpolar comparisons of pops in food ha ...201930818744
microstructure and innervation of the mystacial vibrissal follicle-sinus complex in bearded seals, erignathus barbatus (pinnipedia: phocidae).vibrissal follicle-sinus complexes (f-scs) are sensory receptors of the mammalian integument system. they are best developed within pinnipedia. the objective of this study was to investigate the f-scs of bearded seals (erignathus barbatus) for benthic foraging adaptations. bearded seals possessed approximately 244 mystacial f-scs. in this species, f-scs consisted of an outer dermal capsule (dc) surrounding a blood sinus system [upper cavernous sinus (ucs), ring sinus (rs), and lower cavernous si ...200616342212
pre-partum diet of adult female bearded seals in years of contrasting ice conditions.changing patterns of sea-ice distribution and extent have measurable effects on polar marine systems. beyond the obvious impacts of key-habitat loss, it is unclear how such changes will influence ice-associated marine mammals in part because of the logistical difficulties of studying foraging behaviour or other aspects of the ecology of large, mobile animals at sea during the polar winter. this study investigated the diet of pregnant bearded seals (erignathus barbatus) during three spring breedi ...201222693616
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 ...201222829949
mercury and selenium concentrations in skeletal muscle, liver, and regions of the heart and kidney in bearded seals from alaska, usa.mean concentrations of total mercury ([thg]) and selenium ([tse]) (mass and molar-based) were determined for 5 regions of the heart and 2 regions of the kidney of bearded seals (erignathus barbatus) harvested in alaska, usa, in 2010 and 2011. mean [thg] and [tse] of bearded seal liver and skeletal muscle tissues were used for intertissular comparison. the se:hg molar ratios were used to investigate elemental associations and potential antioxidant protection against hg toxicosis. age was an impor ...201526013477
morphology of the bearded seal (erignathus barbatus) muscular-vibrissal complex: a functional model for phocid subambient pressure generation.bearded seals possess a broad muscular snout with large mystacial vibrissal fields that are involved in tactile sensation and prey identification. although the microstructure of bearded seal vibrissae and their feeding performance have been investigated their orofacial morphology has not. such morphological studies are important to understand the underlying mechanisms of feeding performance and to test proposed functional hypotheses. therefore, the facial musculature was examined in bearded seal ...201627257128
carbon sources and trophic relationships of ice seals during recent environmental shifts in the bering sea.dramatic multiyear fluctuations in water temperature and seasonal sea ice extent and duration across the bering-chukchi continental shelf have occurred in this century, raising a pressing ecological question: do such environmental changes alter marine production processes linking primary producers to upper trophic-level predators? we examined this question by comparing the blubber fatty acid (fa) composition and stable carbon isotope ratios of individual fa (δ¹³cfa) of adult ringed seals (pusa h ...201627411254
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 ...200616387350
prevalence of cryptosporidium spp. and giardia spp. in five marine mammal species.cryptosporidium spp. and giardia spp. are protozoan parasites that are often associated with severe diarrheal disease in a variety of mammals. although these parasites have been extensively studied in terrestrial ecosystems, little is known about either parasite in the marine environment. therefore, the objective of this study was to determine the prevalence of both cryptosporidium spp. and giardia spp. in 5 marine mammal species. fecal samples were collected from 39 bowhead whales (balaena myst ...200516419775
[histology and histochemistry of the seal ovaries and the age-related changes in the ovaries of the greenland seal].histological and histochemical methods were used to study the ovaries of greenland seal (pagophoca groenlandica) from birth-time up to 30 years of age and mature females of phoca vitulina and erignathus barbatus. the ovary of the new-born greenland seal has fetal medullary substance which is a provisory endocrinous gland producing not only sex hormones but also corticosteron. in other species of seals the intestinal cells of the medullary substance are the equivalent of this gland. within 3-4 we ...19764051
bioaccumulation of pcbs and chlorinated pesticides in seals, fishes and invertebrates from the white sea, russia.persistent organochlorines (oc) contaminants, including polychlorinated biphenyl (pcb) congeners, dichlorophenyltrichloroethane (ddt)- and chlordane (chl) related compounds, hexachlorocyclohexanes (hch) isomers and chlorobenzenes (cbz) were determined in blubber of harp seals (phoca groenlandica), ringed seals (phoca hispida) and bearded seals (eringnathus barbatus) as well as in fishes and invertebrates from the white sea, in northwest russia. highest summation operator pcb and summation operat ...200312699922
bioaccumulation of vanadium and other trace metals in livers of alaskan cetaceans and pinnipeds.concentrations for 38 elements are routinely measured in the marine mammal liver tissues archived in the national biomonitoring specimen bank (nbsb). results show that hepatic concentrations of vanadium, selenium, silver, cadmium, and mercury are positively correlated with age for beluga whales (delphinapterus leucas) and of vanadium, selenium, cadmium, and mercury with length for ringed seals (phoca hispada). many researchers have reported linear correlations of hepatic selenium, cadmium, and m ...19968661527
population structure of ice-breeding seals.the development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. other aspects of life history such as geographically distinct vocalizations, female gregariousness, ...200818494764
the commercial harvest of ice-associated seals in the sea of okhotsk, 1972-1994.sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the sea of okhotsk, russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters for species including ringed (pusa hispida), ribbon (histriophoca fasciata), bearded (erignathus barbatus) and spotted (phoca largha) seal. variations in catch per unit effort were explored in relati ...201728796843
distribution of populations of ringed seal phoca hispida and bearded seal erignathus barbatus in shallow and average-deep areas of the southwestern part of the kara sea in summer august-september 2015 in the southwest part of the kara sea, visual censuses of ringed seal (phoca hispida) and bearded seal (erignatus barbatus) from research vessels were carried out in the water area of 49 814 km(2). for the first time, for calculation of abundance and density on ice-free area the seal-calculation (tyulen-raschet) software was used with application of separate extrapolation method by the selected sectors. calculation for the whole census polygon yielded abundance of ringed ...201728702732
seals and sea lions are what they eat, plus what? determination of trophic discrimination factors for seven pinniped species.mixing models are a common method for quantifying the contribution of prey sources to the diet of an individual using stable isotope analysis; however, these models rely upon a known trophic discrimination factor (hereafter, tdf) that results from fractionation between prey and animal tissues. quantifying tdfs in captive animals is ideal, because diet is controlled and the proportional contributions and isotopic values of all prey items are known.201627060839
using simulation to evaluate wildlife survey designs: polar bears and seals in the chukchi sea.logistically demanding and expensive wildlife surveys should ideally yield defensible estimates. here, we show how simulation can be used to evaluate alternative survey designs for estimating wildlife abundance. specifically, we evaluate the potential of instrument-based aerial surveys (combining infrared imagery with high-resolution digital photography to detect and identify species) for estimating abundance of polar bears and seals in the chukchi sea. we investigate the consequences of differe ...201626909183
new data on the blood cell composition of bearded seal. 201526164338
bioaccumulation of radiocaesium in arctic seals.seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. the purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. the study was carried out on harp, ringed, an ...200212523541
underwater vocal complexity of arctic seal erignathus barbatus in kongsfjorden (svalbard).in this study the description of underwater vocal repertoire of bearded seal in svalbard (norway) was extended. two autonomous passive acoustic recorders were deployed for one year (august 2014-july 2015) in the inner and outer parts of the kongsfjorden, and 1728 h were recorded and 17 220 vocalizations were found. nine different vocalization classes were identified and characterized using ten acoustic parameters. the calls showed heterogeneous spectral features, but share the descending trend o ...201729195481
drivers and consequences of apex predator diet composition in the canadian beaufort sea.polar bears (ursus maritimus) rely on annual sea ice as their primary habitat for hunting marine mammal prey. given their long lifespan, wide geographic distribution, and position at the top of the arctic marine food web, the diet composition of polar bears can provide insights into temporal and spatial ecosystem dynamics related to climate-mediated sea ice loss. polar bears with the greatest ecological constraints on diet composition may be most vulnerable to climate-related changes in ice cond ...202032897468
validation of a novel method to create temporal records of hormone concentrations from the claws of ringed and bearded seals.ringed (pusa hispida) and bearded seals (erignathus barbatus) inhabit vast and often remote areas in the arctic, making it difficult to obtain long-term physiological information concerning health and reproduction. these seals are experiencing climate-driven changes in their habitat that could result in physiological stress. chronic physiological stress can lead to immunosuppression, decreased reproduction and decreased growth. recently, keratin has become a popular matrix to measure steroid hor ...202032864135
helminth fauna of ice seals in the alaskan bering and chukchi seas, 2006-15.climate warming may affect the distribution of helminth parasites, allowing endemic species to increase in prevalence and new species to appear. we analyzed tissues from 141 ice-associated seals collected in the alaskan bering and chukchi seas during 2006-15 for internal helminth parasites and compared results with past studies. specimens were collected from: ringed seals (pusa hispida), bearded seals (erignathus barbatus), spotted seals (phoca largha), and ribbon seals (histriophoca fasciata).h ...202032502360
fatty acid-based diet estimates suggest ringed seal remain the main prey of southern beaufort sea polar bears despite recent use of onshore food resources.polar bears (ursus maritimus) from the southern beaufort sea (sb) subpopulation have traditionally fed predominantly upon ice-seals; however, as the proportion of the subpopulation using onshore habitat has recently increased, foraging on land-based resources, including remains of subsistence-harvested bowhead whales (balaena mysticetus) and colonial nesting seabirds has been observed. adipose tissue samples were collected from this subpopulation during the springs of 2013-2016 and analyzed for ...202032128141
no plastics detected in seal (phocidae) stomachs harvested in the eastern canadian arctic.through collaboration with inuit hunters, we examined the stomach contents of 142 seals (ringed seals [phoca hispida; n = 135], bearded seals [erignathus barbatus; n = 6], and one harbour seal [phoca vitualina; n = 1]) hunted between 2007 and 2019 from communities around nunavut to assess whether seals in the eastern canadian arctic ingest and retain plastics in their stomachs. the seals in this study ranged from juveniles to adults of up to 30 years of age, and 55% of the seals were males. we f ...202031787340
assessing vessel slowdown for reducing auditory masking for marine mammals and fish of the western canadian arctic.vessel slowdown may be an alternative mitigation option in regions where re-routing shipping corridors to avoid important marine mammal habitat is not possible. we investigated the potential relief in masking in marine mammals and fish from a 10 knot speed reduction of container and cruise ships. the mitigation effect from slower vessels was not equal between ambient sound conditions, species or vessel-type. under quiet ambient conditions, a speed reduction from 25 to 15 knots resulted in smalle ...201830301040
comparative feeding strategies and kinematics in phocid seals: suction without specialized skull morphology.feeding kinematic studies inform our understanding of behavioral diversity and provide a framework for studying the flexibility and constraints of different prey acquisition strategies. however, little is known about the feeding behaviors used by many marine mammals. we characterized the feeding behaviors and associated kinematics of captive bearded (erignathus barbatus), harbor (phoca vitulina), ringed (pusa hispida) and spotted (phoca largha) seals through controlled feeding trials. all specie ...201829895682
first isolation of brucella pinnipedialis and detection of brucella antibodies from bearded seals erignathus barbatus.brucella species infecting marine mammals was first reported in 1994 and in the years since has been documented in various species of pinnipeds and cetaceans. while these reports have included species that inhabit arctic waters, the few available studies on bearded seals erignathus barbatus have failed to detect brucella infection to date. we report the first isolation of brucella pinnipedialis from a bearded seal. the isolate was recovered from the mesenteric lymph node of a bearded seal that s ...201829565250
habitat selection and seasonal movements of young bearded seals (erignathus barbatus) in the bering sea.the first year of life is typically the most critical to a pinniped's survival, especially for arctic phocids which are weaned at only a few weeks of age and left to locate and capture prey on their own. their seasonal movements and habitat selection are therefore important factors in their survival. during a cooperative effort between scientists and subsistence hunters in october 2004, 2005, and 2006, 13 female and 13 male young (i.e., age <2) bearded seals (erignathus barbatus) were tagged wit ...201829489846
spring fasting behavior in a marine apex predator provides an index of ecosystem productivity.the effects of declining arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter-specifically, spatially, and temporally. because marine mammals occupy upper trophic levels in arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. polar bears (ursus maritimus) are apex predators that primarily consume benthic and pelagic-feeding ice-associated seals. as such, their productivity integrates sea ice con ...201828994242
potential impacts of shipping noise on marine mammals in the western canadian the arctic warms and sea ice decreases, increased shipping will lead to higher ambient noise levels in the arctic ocean. arctic marine mammals are vulnerable to increased noise because they use sound to survive and likely evolved in a relatively quiet soundscape. we model vessel noise propagation in the proposed western canadian arctic shipping corridor in order to examine impacts on marine mammals and marine protected areas (mpas). our model predicts that loud vessels are audible underwater ...201728918981
individual variability in diving, movement and activity patterns of adult bearded seals in svalbard, norway.bearded seals are one of the least studied arctic marine mammals, despite their circumpolar distribution and importance as a resource to inuit communities. in this study, adult bearded seals (erignathus barbatus) were equipped with gps-argos-ctd-srdls in svalbard, norway (2011-2012, n = 7) to document their diving, activity and movement patterns in a region where their habitat is changing rapidly. five seals transmitted for > 8 months, sending 21,738 gps-positions and 17,866 dives between july a ...201830451906
comparative health assessments of alaskan ice seals.bearded (erignathus barbatus), ringed (pusa hispida), spotted (phoca largha), and ribbon (histriophoca fasciata) seals rely on seasonal sea-ice in arctic and sub-arctic regions. many aspects of the biology and physiology of these seals are poorly known, and species-typical health parameters are not available for all species. such information has proven difficult to obtain due to the challenges of studying arctic seals in the wild and their minimal historic representation in aquaria. here, we com ...201930792982
organochlorine contaminants in blubber of four seal species: integrating biomonitoring and specimen banking.blubber samples from four alaska seal species (bearded seal, erignathus barbatus, harbor seal, phoca vitulina, northern fur seal, callorhinus ursinus, ringed seal, p. hispida) were collected for inclusion in the us national biomonitoring specimen bank, as well as for immediate analysis as part of the contaminant monitoring component of the us national marine fisheries service's marine mammal health and stranding response program. the blubber samples were analyzed for organochlorine (oc) contamin ...19979159908
prevalence of algal toxins in alaskan marine mammals foraging in a changing arctic and subarctic environment.current climate trends resulting in rapid declines in sea ice and increasing water temperatures are likely to expand the northern geographic range and duration of favorable conditions for harmful algal blooms (habs), making algal toxins a growing concern in alaskan marine food webs. two of the most common hab toxins along the west coast of north america are the neurotoxins domoic acid (da) and saxitoxin (stx). over the last 20 years, da toxicosis has caused significant illness and mortality in m ...201628073526
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 ...201323640921
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 ...200818494365
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 ...201222907891
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