Publications

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polybrominated diphenyl ethers (pbdes) in seal populations from eastern and western canada: an assessment of the processes and factors controlling pbde distribution in seals.polybrominated diphenyl ether (pbde) concentrations were measured in the blubber of five mother-pup pairs of grey seals (halichoerus grypus) from sable island, nova scotia (ns) sampled in 1995 and in 20 harbour seals (phoca vitulina) from british columbia (bc) sampled in 1991-1992. concentrations in maternal grey seals from sable island averaged 112+/-55.2 ng/g lipid (mean+/-s.d.) and were over twice the concentrations measured in their pups; higher brominated pbdes showed a distinct decline in ...200818359511
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
is there a link between hypospadias and organochlorine exposure in east greenland sledge dogs (canis familiaris)?in a clinical survey on east greenland male sledge dogs (canis familiaris), one dog exhibited malformation of the external genital organs. the clinically in situ examination of the sledge dog revealed a rare congenital malformation of the urethra and penis corresponding to severe perineal and penile hypospadias. the testes showed spermiogenesis and no sign of true hermaphroditism. we did not have the opportunity to examine the dam for endocrine organ pathology or tumours. but, based on organochl ...200818061260
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
ringed seal post-moulting movement tactics and habitat selection.intra-specific and intra-population variation in movement tactics have been observed in many species, sometimes in association with alternative foraging techniques or large-scale habitat selection. however, whether animals adjust their small-scale habitat selection according to their large-scale tactics has rarely been studied. this study identified two large-scale movement tactics in ringed seals (phoca hispida) during their non-breeding, post-moulting period. first-passage times (fpt) were use ...200817990001
spatial trends of perfluoroalkyl compounds in ringed seals (phoca hispida) from the canadian arctic.the present study examined spatial trends of perfluoroalkyl compounds (pfcs) in liver samples from 11 populations of ringed seals (phoca hispida) in the canadian arctic from 2002 to 2005. trophic position and relative carbon sources were compared by analyzing stable nitrogen and carbon isotopes in muscle samples. geometric mean concentrations of total c9-c15 perfluorinated carboxylates (pfcas) ranged from 8.8 to 84 ng/g wet weight, and c9-c11 pfcas predominated. perfluorooctane sulfonate was the ...200817988182
levels and temporal trends of hch isomers in ringed seals from west and east greenland.levels and temporal trends of the hexachlorocyclohexane isomers alpha-, beta- and gamma-hch were analysed in blubber of juvenile ringed seals from west greenland (1994 to 2006) and juvenile and adult ringed seals from east greenland (1986 to 2006). no significant differences in the concentration levels in the juvenile seals were found between east and west greenland for any of the three isomers. alpha-hch concentrations were not significantly different between juvenile and adult ringed seals fro ...200818688462
biomarker responses and decreasing contaminant levels in ringed seals (pusa hispida) from svalbard, norway.blubber was analyzed for a wide range of contaminants from five sub-adult and eight adult male ringed seals sampled in 2004, namely, for polychlorinated biphenyls (pcbs), hexachlorobenzene (hcb), toxaphenes, chlordanes, dichlorodiphenyldichloroethylene (dde), and polybrominated diphenylethers (pbdes). contaminant levels were compared to previously sampled animals from the same area, as well as data from literature for other arctic wildlife species from a wide variety of locations. ringed seals s ...200818569610
stratification, composition, and function of marine mammal blubber: the ecology of fatty acids in marine mammals.abstract this study of vertical fatty acid profiles, based on analysis of 58 fatty acids sampled at 3-mm intervals throughout the blubber column of a model marine mammal, the ringed seal (pusa hispida), revealed three chemically distinct layers. the average depths of the outer and inner layers were quite consistent (approximately 1.5 and approximately 1 cm, respectively). consequently, the middle layer varied greatly in thickness, from being virtually absent in the thinnest animals to 2.5 cm thi ...200818532882
seasonal activity budget of adult baltic ringed seals.although ringed seals are important components in oceanic and fresh water ecosystems at high latitudes, little is known about how they exploit these harsh environments. seasonal activity and diving behaviour of 19 adult baltic ringed seals were studied by satellite telemetry. we elaborated an activity budget for ten months of the year, extending over the period from moult to the breeding season. seals from three main regions showed explicit site fidelity and the distributions of animals tagged f ...200818414676
macroscopic anatomy of the heart of the ringed seal (phoca hispida).anatomical properties of the ringed seal (phoca hispida) heart and associated blood vessels reveal adaptations related to requirements for diving. seven adult ringed seals were embalmed and dissected to document the gross anatomical features of the heart. computed tomography images of the thoracic cavity were taken on one seal prior to dissection. the shape and position of the heart is different from the typical carnivore heart. the most notable difference is its dorsoventral flattened appearanc ...200818197897
levels and trends of persistent organic pollutants in ringed seals (phoca hispida) from central west greenland, with particular focus on polybrominated diphenyl ethers (pbdes).polybrominated diphenyl ethers (pbdes) and the organochlorine compounds polychlorinated biphenyls (pcbs), ddts, hcb, chlordane-related pesticides, hch and toxaphene were analysed in blubber of juvenile ringed seals from central west greenland collected between 1982 and 2006. the longest time series could be established for pbdes, partly based on archived material, while pcbs and ddts covered a study period from 1994-2006. all organochlorines showed decreasing trends, most pronounced for ddt and ...200818155150
biotransformation of pcbs in relation to phase i and ii xenobiotic-metabolizing enzyme activities in ringed seals (phoca hispida) from svalbard and the baltic sea.polychlorinated biphenyls (pcbs) may induce activity of hepatic enzymes, mainly phase i monooxygenases and conjugating phase ii enzymes, that catalyze the metabolism of pcbs leading to formation of metabolites and to potential adverse health effects. the present study investigates the concentration and pattern of pcbs, the induction of hepatic phase i and ii enzymes, and the formation of hydroxy (oh) and methylsulfonyl (ch3so2=meso2) pcb metabolites in two ringed seal (phoca hispida) populations ...200819192824
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
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
a study of metal concentrations and metallothionein binding capacity in liver, kidney and brain tissues of three arctic seal species.arctic seals are known to accumulate relatively high concentrations of potential toxic heavy metals in their vital organs, such as livers and kidneys, as well as in their central nervous system. we therefore decided to determine whether mercury, copper, cadmium and zinc levels in liver, kidney and brain tissues of three arctic seal species were associated with the intracellular metal-binding protein metallothionein (mt) as a sign of toxic exposure. samples from four ringed (phoca hispida), five ...200919773017
macroscopic anatomy of the great vessels and structures associated with the heart of the ringed seal (pusa hispida).the ringed seal [pusa (phoca) hispida], as well as other seals, exhibits unique anatomical properties when compared to its terrestrial counterparts. in the ringed seal, the most conspicuous marine adaptation is the aortic bulb. this large dilatation of the ascending aorta is comparable to that found in other seal species and marine mammals. the branches of the ascending aorta (brachiocephalic trunk, left common carotid artery and left subclavian artery) are similar to those of higher primates an ...200919245671
trophodynamics of some pfcs and bfrs in a western canadian arctic marine food web.the trophodynamics of per- and polyfluorinated compounds and bromine-based flame retardants were examined in components of a marine food web from the western canadian arctic. the animals studied and their relative trophic status in the food web, established using stable isotopes of nitrogen (delta15n), were beluga (delphinapterus leucas) > ringed seal (phoca hispida) > arctic cod (boreogadus saida) > pacific herring (clupea pallasi) approximately equal to arctic cisco (coregonus autumnalis) > pe ...200919569333
long-term changes of mercury levels in ringed seal (phoca hispida) from amundsen gulf, and beluga (delphinapterus leucas) from the beaufort sea, western canadian arctic.mercury (hg) concentrations were determined in the canine teeth of ringed seals (phoca hispida) harvested during the 13th-14th, late 19th and early 21st centuries in amundsen gulf, northwest territories, canada. most historical and pre-industrial teeth contained undetectable hg levels (i.e. <1.0 ng/g dw), whereas samples from 2001-03 contained up to 12 ng/g dw in an age-dependent pattern. assuming a median [hg] value in 13th-14th century teeth of half the detection limit (i.e. 0.5 ng/g dw), geom ...200919766293
seasonal energetics of northern phocid seals.the metabolic rate of harp (pagophilus groenlandicus), harbor (phoca vitulina), and ringed seals (pusa hispida) was measured at various temperatures in air and water to estimate basal metabolic rates (bmrs) in these species. the basal rate and body composition of three harp seals were also measured throughout the year to examine the extent to which they vary seasonally. marine mammalian carnivores generally have bmrs that are over three times the rates expected from body mass in mammals generall ...200919049825
polybrominated diphenyl ethers and their hydroxylated analogues in ringed seals (phoca hispida) from svalbard and the baltic sea.the present study investigated the concentrations and patterns of pbdes and hydroxylated (oh) pbde analogues in two ringed seal populations: less contaminated svalbard and more contaminated baltic sea. mean concentration of hepatic sigma-pbde, which was dominated by bde47, was six times higher in the ringed seals from the baltic sea compared to the seals from svalbard. bde47/sigma-pbde was higher in the seals from svalbard compared to that for baltic seals, while the trend was opposite for bde15 ...200919544845
macroscopic anatomy of the ringed seal [pusa (phoca) hispida] lower respiratory system.this investigation serves to document the normal anatomical features of the lower respiratory tract of the ringed seal [pusa (phoca) hispida]. evaluation of embalmed specimens and tracheobronchial casts showed that the right lung of this seal consists of four lobes while the left has only three lobes. the ventral margins of the lungs do not reach the sternum causing them to form the boundary of the broad recessus costomediastinalis. lung lobation corresponds with bronchial tree division. pulmona ...200919245669
hexachlorocyclohexanes (hch) in ringed seal (phoca hispida) from ulukhaktok (holman), nt: trends from 1978 to 2006.trends in alpha-, beta-, and gamma-hexachlorocyclohexane (hch) concentrations were examined in blubber lipid of ringed seals (phoca hispida) from ulukhaktok (holman), nt (canada) sampled at intervals between 1978 and 2006. alpha-hch usually represented approximately 90% of the total hch isomers. alpha-hch and gamma-hch concentrations showed no change over the sampling interval, but beta-hch concentrations increased significantly, about 8-10-fold in females and 4-5-fold in males. residue concentr ...200919560798
mercury trends in ringed seals (phoca hispida) from the western canadian arctic since 1973: associations with length of ice-free season.we examined a unique time series of ringed seal (phoca hispida) samples collected from a single location in the western canadian arctic between 1973 and 2007 to test for changes in total mercury (thg) in muscle tissue associated with (1) year and (2) length of ice-free season. we found no temporal trend with muscle thg whereas a curvilinear relationship existed with the length of ice-free season: seals attaimed higher thg in short (2 months) and long (5 months) ice-free seasons. delta 15n and de ...200919544867
mercury concentrations in southern beaufort sea polar bears: variation based on stable isotopes of carbon and nitrogen.total hg concentration was measured in hair and whole blood of 52 adult southern beaufort sea polar bears (ursus maritimus) captured in the spring of 2005. stable isotopic signatures (i.e., 13c/12c, delta13c; 15n/14n, delta15n) in hair and two blood compartments (packed blood cells/clot and serum) were determined to assess the variation of hg concentrations among polar bears in relation to their feeding ecology and other biological factors. concentrations of hg in hair and blood (2.2-23.9 microg ...200919226182
estimated dietary exposure to fluorinated compounds from traditional foods among inuit in nunavut, canada.increasing evidence shows that persistent organic pollutants such as perfluorinated compounds (pfcs) are found in the arctic ecosystem and their prevalence is causing human health concerns. the objective of this study was to estimate dietary exposure to pfcs among inuit in northern canada. perfluorooctane sulfonate (pfos), perfluorinated carboxylates (pfca c(7)-c(11)) and fluorotelomer unsaturated carboxylic acids (6:2, 8:2 and 10:2 ftuca) were measured in 68 traditional foods collected in nunav ...200919342075
bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (pusa hispida) and polar bears (ursus maritimus) from east greenland.we report on the comparative bioaccumulation, biotransformation and/or biomagnification from east greenland ringed seal (pusa hispida) blubber to polar bear (ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (pcbs), chlordanes (chls), hydroxyl (oh-) and methylsulfonyl (meso(2)-) pcbs, polybrominated biphenyls (pbbs), oh-pbbs, polybrominated diphenyl ether ...200919683343
implications of climate change for northern canada: freshwater, marine, and terrestrial ecosystems.climate variability and change is projected to have significant effects on the physical, chemical, and biological components of northern canadian marine, terrestrial, and freshwater systems. as the climate continues to change, there will be consequences for biodiversity shifts and for the ranges and distribution of many species with resulting effects on availability, accessibility, and quality of resources upon which human populations rely. this will have implications for the protection and mana ...200919714961
reproductive performance in east greenland polar bears (ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (pbpk) modelling.polar bears (ursus maritimus) feed mainly on ringed seal (phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (ohcs) worldwide. in east greenland, studies of ohc time trends and organ system health effects, including reproductive, were conducted during 1990-2006. however, it has been difficult to determine the nature of the effects induced by ohc exposures on wild caught polar bears using body burden ...200919863991
aquatic environment and differentiation of vibrissae: comparison of sinus hair systems of ringed seal, otter and pole cat.this study investigated the structure and innervation of the vibrissal systems of the pole cat (mustela putorius), european otter (lutra lutra) and ringed seal (phoca hispida) in order to find adaptations to aquatic environment. the number of myelinated nerve fibers of deep vibrissal nerve (dvn) of the entire vibrissal system was considerably greater in the ringed seal (10x, aquatic mammal) and in the otter (4x, semi-aquatic mustelid) compared to the pole cat which is a terrestrial mustelid. sim ...200919996585
helminth parasites in ringed seals (pusa hispida) from svalbard, norway with special emphasis on nematodes: variation with age, sex, diet, and location of host.complete gastrointestinal tracts from 257 ringed seals (pusa hispida) from svalbard, norway, were examined for helminth parasites. three different helminth groups were recorded (acanthocephalans 61.1%; nematodes 38%; cestodes 0.9%). acanthocephalans (polymorphidae) and cestodes (anophryocephalus and diphyllobothrium sp(p)., as well as unidentified species, were confined to the intestines. the anisakid nematodes phocascaris phocae, pseudoterranova sp(p)., anisakis sp(p)., and phocascaris/contraca ...201020950103
exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish.persistent organic pollutants (pops) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially pops categorized as organohalogen contaminants (ohcs). ohcs have been of concern in the circumpolar arctic for decades. for example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated pcbs, ddts and chls) and emerging (e.g., bromin ...201019910021
polychlorinated naphthalenes in polar environments--a review.polychlorinated naphthalenes (pcns) consist of naphthalene substituted with 1-8 chlorines, yielding 75 possible congeners. they were formerly used in industry, occur at trace levels in commercial pcb mixtures, and have current sources in combustion processes. pcns are widespread in arctic air with higher levels in the european arctic. concentrations were higher during the cold months in arctic canada and russia, but no seasonality was noted in subarctic canada and greenland. "marker" congeners i ...201019892388
levels and trends of poly- and perfluorinated compounds in the arctic environment.poly- and perfluorinated organic compounds (pfcs) are ubiquitous in the arctic environment. several modeling studies have been conducted in attempt to resolve the dominant transport pathway of pfcs to the arctic-atmospheric transport of precursors versus direct transport via ocean currents. these studies are generally limited by their focus on perfluorooctanoate (pfoa) fluxes to arctic seawater and thus far have only used fluorotelomer alcohols (ftohs) and sulfonamide alcohols as inputs for vola ...201020493516
a computational model of teeth and the developmental origins of morphological variation.the relationship between the genotype and the phenotype, or the genotype-phenotype map, is generally approached with the tools of multivariate quantitative genetics and morphometrics. whereas studies of development and mathematical models of development may offer new insights into the genotype-phenotype map, the challenge is to make them useful at the level of microevolution. here we report a computational model of mammalian tooth development that combines parameters of genetic and cellular inte ...201020220757
the nature of mitochondrial monoamine oxidase from the seal (phoca hispida ladogensis) liver. 201020714847
an evaluation of teeth of ringed seals (phoca hispida) from greenland as a matrix to monitor spatial and temporal trends of mercury and stable isotopes.total mercury (hg) concentrations were measured in teeth of ringed seals from qeqertarsuaq, central west greenland (1982 to 2006) and ittoqqortoormiit, central east greenland (1986 to 2006). stable isotopic ratios of carbon ((13)c/(12)c) and nitrogen ((15)n/(14)n) were determined as well to provide insights into diet variations between regions or through time. mercury concentrations decreased the first years of life of the animals suggesting that hg had been transferred from the mother to the fo ...201020696465
hormone, vitamin and contaminant status during the moulting/fasting period in ringed seals (pusa [phoca] hispida) from svalbard.this study investigates the potential effects of moulting, and the concomitant period of fasting undertaken by ringed seals, on hormone, vitamin and contaminant status in adult animals in a population from svalbard, norway, which has relatively low contaminant levels. concentrations of circulating total and free thyroxine and triiodothyronine, circulating and hepatic vitamin a, hepatic persistent organic pollutants and their circulating hydroxyl metabolites were higher in moulting seals compared ...201019800979
comparative endocrine disruptive effects of contaminants in ringed seals (phoca hispida) from svalbard and the baltic sea.we investigated variables related to thyroid, vitamin a and calcitriol homeostasis, immune function and tumour development in ringed seals (phoca hispida) from the polluted baltic sea and a less polluted reference location at svalbard, norway. we also examined the relationships between the biological variables and the concentrations of persistent organic pollutants (pops) and their hydroxylated (oh) metabolites. our data show higher plasma concentrations of free triiodothyronine (t3), and ratios ...201020624697
ecosystem changes in the neva estuary (baltic sea): natural dynamics or response to anthropogenic impacts?the neva estuary situated in the eastern gulf of finland is one of the largest estuaries of the baltic sea with a large conurbation, st. petersburg, situated on its coast. eutrophication, alien species and large-scale digging and dumping of bottom sediment are the most prominent anthropogenic impacts on its ecosystem. however, many ecosystem responses, which are traditionally attribute to these impacts, are related to natural dynamics of the ecosystem. fluctuations in discharge of the neva river ...201020347454
DETECTION OF CRYPTOSPORIDIUM SP. SEAL IN TWO NEW SEAL SPECIES, PHOCA VITULINA AND CYSTOPHORA CRISTATA AND A NOVEL CRYPTOSPORIDIUM GENOTYPE IN A THIRD SEAL SPECIES, PAGOPHILUS GROENLANDICUS FROM THE GULF OF MAINE.Abstract Data on the geographic distribution and host-specificity of Cryptosporidium spp. are critical for developing an understanding of likely transmission patterns in nature. During a molecular based survey of fecal samples from 293 terrestrial and aquatic animals in Maine, we detected Cryptosporidium sp. in 11 harbor seals, 1 hooded seal, and 1 harp seal. None of the terrestrial or freshwater mammal fecal samples or bird samples tested positive for Cryptosporidium sp. However, the seque ...201122017467
regional contamination versus regional dietary differences: understanding geographic variation in brominated and chlorinated contaminant levels in polar bears.the relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (ursus maritimus) contaminant levels is unknown. dietary variation between alaska, canada, east greenland, and svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (δ(15)n, δ(13)c) and adipose fatty acid (fa) signatures relative to their main prey (ringed seals). western and southern hudson bay signatures were characterized by depleted δ(15)n and δ(13) ...201121166451
temporal trends of hexabromocyclododecane, polybrominated diphenyl ethers and polychlorinated biphenyls in ringed seals from east greenland.concentrations of hexabromocyclododecane (hbcd) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from east greenland collected between 1986 and 2008. α-hbcd was the only diastereoisomer consistently above levels of quantification and showed a significant log-linear (exponential) increase from 2.0 to 8.7 ng/g lipid weight (median concentrations) with an annual rate of +6.1%. the concentrations were up to several orders of magnitude lower than those r ...201121247098
persistent organic pollutants in ringed seals from the russian arctic.organochlorine compounds total ddt (σddt), total hch isomers (σhch), toxaphenes (sum of parlar 26, 50, 62), mirex, endrin, methoxychlor, total chlorinated benzenes (σcbz), total chlordane compounds (σchl), polychlorinated biphenyls (total of 56 congeners; σpcbs), polychlorinated dibenzo-p-dioxins and furans (pcdd/fs), and polybrominated diphenyl ethers (sum of 7 tri- to hepta congeners; σpbdes) were analysed in the blubber of adult ringed seals from the four areas of the russian arctic (white se ...201121636111
questions--and cases--mount in seal disease outbreak: mystery illness killing arctic ringed seals may be spreading. 201122250323
mercury hair concentrations and dietary exposure among inuit preschool children in nunavut, canada.there is concern that the traditional diet is a source of mercury exposure among inuit in the canadian arctic. mercury exposure in utero and in early childhood presents a risk to neurodevelopment. the objectives of the present study were to assess the dietary mercury exposure from traditional food among inuit children 3 to 5 years of age in nunavut, and evaluate the association between estimated dietary mercury intake and body burden. a cross-sectional nunavut inuit child health survey was condu ...201120673686
a simple route to single-nucleotide polymorphisms in a nonmodel species: identification and characterization of snps in the artic ringed seal (pusa hispida hispida).although single-nucleotide polymorphisms (snps) have become the marker of choice in the field of human genetics, these markers are only slowly emerging in ecological, evolutionary and conservation genetic analyses of nonmodel species. this is partly because of difficulties associated with the discovery and characterization of snp markers. herein, we adopted a simple straightforward approach to identifying snps, based on screening of a random genomic library. in total, we identified 768 snps in t ...201121429159
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 ...201121437940
trichinella nativa in grey seal halichoerus grypus - spill-over from a highly endemic terrestrial ecosystem.abstract trichinella infections of marine mammals pose a human health risk in arctic regions where game meat is important part of the diet. in the last decade, the grey seal population of the subarctic baltic sea has reached a level at which hunting is possible and seal meat is now available for food. we conducted a survey on the occurrence of trichinella spp. in grey seals halichoerus grypus (n = 171) and ringed seals phoca hispida botnica (n = 56) of the baltic sea in the coastal waters of fin ...201121506828
spatio-temporal variations and age effect on toxoplasma gondii seroprevalence in seals from the canadian arctic.summarytoxoplasmosis is a significant public health threat for inuit in the canadian arctic. this study aimed to investigate arctic seals as a possible food-borne source of infection. blood samples collected from 828 seals in 7 canadian arctic communities from 1999 to 2006 were tested for toxoplasma gondii antibodies using a direct agglutination test. polymerase chain reaction (pcr) was used to detect t. gondii dna in tissues of a subsample of seals. associations between seal age, sex, species, ...201121813043
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
species-specific time trends and enantiomer fractions of hexabromocyclododecane (hbcd) in biota from east greenland.time trends of hexabromocyclododecane (hbcd) isomers were studied for glaucous gull and ringed seal from east greenland. the ringed seal results extended a previous time trend (1986-2008) to 2010. α-hbcd was the only isomer consistently above quantification limits. for glaucous gull liver, annual median values of α-hbcd (1994-2010) ranged from 22 to 120 ng/g lipid weight (lw) with no significant trend, while hbcd in ringed seal blubber from the same area showed a significant increase from 3.9 to ...201222994606
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
polychlorinated naphthalenes (pcns) in sub-arctic and arctic marine mammals, 1986-2009.a selection of pcn congeners was analyzed in pooled blubber samples of pilot whale (globicephala melas), ringed seal (phoca hispida), minke whale (balaenoptera acutorostrata), fin whale (balaenoptera physalus), harbour porpoise (phocoena phocoena), hooded seal (cystophora cristata) and atlantic white-sided dolphin (lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). a large geographical area of the north atlantic and arctic areas was covered. pcn congeners 48, 52, 5 ...201222356752
methoxylated polybrominated diphenyl ethers (meo-pbdes) are major contributors to the persistent organobromine load in sub-arctic and arctic marine mammals, 1986-2009.a selection of meo-bde and bde congeners were analyzed in pooled blubber samples of pilot whale (globicephala melas), ringed seal (phoca hispida), minke whale (balaenoptera acutorostrata), fin whale (balaenoptera physalus), harbor porpoise (phocoena phocoena), hooded seal (cystophora cristata), and atlantic white-sided dolphin (lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). the analytes were extracted and cleaned-up using open column extraction and multi-layer ...201222225820
increasing levels of long-chain perfluorocarboxylic acids (pfcas) in arctic and north atlantic marine mammals, 1984-2009.temporal variations in concentrations of perfluorinated carboxylic acids (pfcas) and sulfonic acids (pfsas), including perfluorooctane sulfonate (pfos) and perfluorooctanoate (pfoa) structural isomers, were examined in livers of pilot whale (globicephala melas), ringed seal (phoca hisida), minke whale (balaenoptera acutorostrata), harbor porpoise (phocoena phocoena), hooded seal (cystophora cristata), atlantic white-sided dolphin (lagenorhynchus acutus) and in muscle tissue of fin whales (balaen ...201222051347
polybrominated diphenyl ethers (pbdes) in marine mammals from arctic and north atlantic regions, 1986-2009.a selection of pbde congeners was analyzed in pooled blubber samples of pilot whale (globicephala melas), ringed seal (phoca hispida), minke whale (balaenoptera acutorostrata), fin whale (balaenoptera physalus), harbor porpoise (phocoena phocoena), hooded seal (cystophora cristata) and atlantic white-sided dolphin (lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). the analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel co ...201221802148
level and temporal trend of perfluoroalkyl acids in greenlandic inuit.perfluoroalkyl acids (pfaas) have been detected in human blood, breast milk and umbilical cord blood across the globe. pfaas do accumulate in the marine food chain in arctic regions. in greenland, increasing pfaa concentrations were observed during 1982-2006 in ringed seals and polar bears. however, until now, no data have been reported for pfaas in greenlandic inuit. this study assesses the level and temporal trend of serum pfaas in greenlandic inuit.201228417759
level and temporal trend of perfluoroalkyl acids in greenlandic inuit.perfluoroalkyl acids (pfaas) have been detected in human blood, breast milk and umbilical cord blood across the globe. pfaas do accumulate in the marine food chain in arctic regions. in greenland, increasing pfaa concentrations were observed during 1982-2006 in ringed seals and polar bears. however, until now, no data have been reported for pfaas in greenlandic inuit. this study assesses the level and temporal trend of serum pfaas in greenlandic inuit.201222456049
western canadian arctic ringed seal organic contaminant trends in relation to sea ice break-up.the association between changing sea ice conditions and contaminant exposure to arctic animals interests inuvialuit harvesters, communities, and researchers. we examined organochlorine contaminant (oc) concentrations in the blubber of 90 male adult ringed seals (phoca hispida) sampled from the subsistence harvest in ulukhaktok (formerly holman), nt, canada, just prior to break-up of the sea ice (1993-2008). oc blubber concentrations were assessed with respect to year and sea ice break-up date. h ...201222428683
a methodology for evaluating the influence of diets and intergenerational dietary transitions on historic and future human exposure to persistent organic pollutants in the arctic.concentrations of persistent organic pollutants (pops) in inuit populations have been observed to decrease over the last decade. the main objective of this study was to develop a methodology to quantify the potential influence of intergenerational dietary transitions on human exposure to organic contaminants in the arctic environment using pcb-153 as a case study. long-term (1930-2050) dynamic simulations using realistic emission estimates were conducted using linked chemical fate and bioaccumul ...201222982224
effects of climate warming on polar bears: a review of the evidence.climate warming is causing unidirectional changes to annual patterns of sea ice distribution, structure, and freeze-up. we summarize evidence that documents how loss of sea ice, the primary habitat of polar bears (ursus maritimus), negatively affects their long-term survival. to maintain viable subpopulations, polar bears depend on sea ice as a platform from which to hunt seals for long enough each year to accumulate sufficient energy (fat) to survive periods when seals are unavailable. less tim ...201224501049
linking climate trends to population dynamics in the baltic ringed seal: impacts of historical and future winter temperatures.a global trend of a warming climate may seriously affect species dependent on sea ice. we investigated the impact of climate on the baltic ringed seals (phoca hispida botnica), using historical and future climatological time series. availability of suitable breeding ice is known to affect pup survival. we used detailed information on how winter temperatures affect the extent of breeding ice and a climatological model (rca3) to project the expected effects on the baltic ringed seal population. th ...201222851349
antioxidative defense and oxidative stress in ringed seals (pusa hispida) from differently polluted areas.high contaminant levels detected in baltic seals have been associated with various health effects. in this study several parameters related to antioxidative defense and oxidative stress (concentrations of reduced and oxidised glutathione, lipid hydroperoxide and vitamin e, activities of glutathione reductase, peroxidase and s-transferase, glucose-6-phosphate dehydrogenase, catalase, and superoxidedismutase) were measured in the livers of ringed seals from the baltic sea and from a less contamina ...201222417762
mystery illness killing arctic ringed seals may be spreading. 201222303555
trophic transfer of contaminants in a changing arctic marine food web: cumberland sound, nunavut, canada.contaminant dynamics in arctic marine food webs may be impacted by current climate-induced food web changes including increases in transient/subarctic species. we quantified food web organochlorine transfer in the cumberland sound (nunavut, canada) arctic marine food web in the presence of transient species using species-specific biomagnification factors (bmfs), trophic magnification factors (tmfs), and a multifactor model that included δ(15)n-derived trophic position and species habitat range ( ...201222957980
viral metagenomics: a tool for virus discovery and diversity in aquaculture.viruses are abundant biological entities on earth and the emergence of viral pathogens has become a serious threat to aquaculture and fisheries worldwide. however, our response to viral pathogens has been largely reactive, in the sense that a new pathogen is usually not discovered until it has already reached epidemic proportions. current diagnostic methods such as pcr, immunological assays and pan-viral microarrays are limited in their ability to identify novel viruses. in this context, the kno ...201223997432
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
temporal trends of mercury in greenland ringed seal populations in a warming climate.temporal trends of mercury in livers of ringed seals collected from the early 1980s to 2010 from central west, northwest and central east greenland were studied. in this period the climate of greenland warmed and the influences of climate indices such as ice coverage, water temperature and the atlantic oscillation index on mercury concentration were evaluated using multiple regressions and akaike's information criteria (aic) to determine the most parsimonious models. biological co-variables such ...201223152143
temporal trends of selected pops and the potential influence of climate variability in a greenland ringed seal population.temporal trends of selected pops (pcb-52 and 153, p,p'-dde, hcb, α- and β-hch) in blubber of ringed seals (pusa hispida) collected from the early 1990s to 2010 from central west greenland were studied. in this period, the climate of greenland warmed and the influences of climate indices such as winter sea-ice coverage (november-may), the number of sea-ice days during winter in disko bay, water temperature and salinity at fyllas banke during the preceding summer and the arctic oscillation index ( ...201323831938
[the reactivity of liver monoamine oxidase in the ringed seal phoca hispida ladogensis].the goal of the work consisted in study of substrate and inhibitor specificity of liver monoamine oxidase (mao) of the freshwater ladoga subspecies of the ringed seal phoca hispida ladogensis. the studied enzyme has been established to have large substrate specificity by deaminating, apart from eight classic substrates of mao of terrestrial mammals, also histamine, the diamine oxidase substrate. it is found out that the deamination rates of benzylamine, beta-phenylethylamine, and n-methylhistami ...201323789395
polar bears: the fate of an icon.polar bears are one of the most iconic animals on our planet. worldwide, even people who would never see one are drawn to these charismatic arctic ice hunters. they are the world's largest terrestrial carnivore, and despite being born on land, they spend most of their lives out on the sea ice and are considered a marine mammal. current global studies estimate there are around 20,000 animals in some 19 discrete circumpolar populations. aside from pregnant females denning in the winter months to g ...201324331553
combined genetic and telemetry data reveal high rates of gene flow, migration, and long-distance dispersal potential in arctic ringed seals (pusa hispida).ringed seals (pusa hispida) are broadly distributed in seasonally ice covered seas, and their survival and reproductive success is intricately linked to sea ice and snow. climatic warming is diminishing arctic snow and sea ice and threatens to endanger ringed seals in the foreseeable future. we investigated the population structure and connectedness within and among three subspecies: arctic (p. hispida hispida), baltic (p. hispida botnica), and lake saimaa (p. hispida saimensis) ringed seals to ...201324130843
trends of perfluorochemicals in greenland ringed seals and polar bears: indications of shifts to decreasing trends.time-series of perfluorinated alkylated substances (pfass) in east greenland polar bears and east and west greenland ringed seals were updated in order to deduce whether a response to the major reduction in perfluoroalkyl production in the early 2000s had occurred. previous studies had documented an exponential increase of perfluorooctane sulphonate (pfos) in liver tissue from both species. in the present study, pfos was still the far most dominant compound constituting 92% (west greenland ringe ...201324025534
pathological changes of stomach in ringed seal (pusa hispida) from arviat (north canada) caused by anisakid nematodes.this is a report of lesions associated with the nematodes (anisakidae) from the stomach of ringed seals (pusa hispida). on thirty one examined ringed seals from arviat, thirteen were infected by 1 to 24 anisakids. identification of nematodes from their stomachs showed two species; contracaecum osculatum (sensu lato) (79 specimens) and pseudoterranova decipiens (sensu lato) (11 specimens). in the gastric sections with parasites, larvae and adults of nematodes were present mainly in the fundic por ...201323691577
concentrations, patterns and metabolites of organochlorine pesticides in relation to xenobiotic phase i and ii enzyme activities in ringed seals (phoca hispida) from svalbard and the baltic sea.the present study investigates the concentrations and patterns of organochlorine pesticides (ocps) and their metabolites in liver and plasma of two ringed seal populations (phoca hispida): lower contaminated svalbard population and more contaminated baltic sea population. among ocps, p,p'-dde and sum-chlordanes were the highest in concentration. with increasing hepatic contaminant concentrations and activities of xenobiotic-metabolizing enzymes, the concentrations of 3-methylsulfonyl-p,p'-dde an ...201319329238
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
a two-dimensional hplc separation for the enantioselective determination of hexabromocyclododecane (hbcd) isomers in biota samples.a new method for enantioselective analysis of isomers of hexabromocyclododecane (hbcd) is described, using a two-dimensional high-performance liquid chromatography (hplc) approach to avoid coelution, in particular between (+) α-hbcd, (+) β-hbcd, or (+) γ-hbcd. after isomer separation on a conventional column, the single isomers are transferred to an enantioselective hplc column using heart cuts. two enantioseparations are conducted in two separate partial chromatograms: one for α-hbcd and one fo ...201323831754
clarifying relationships between persistent organic pollutant concentrations and age in wildlife biomonitoring: individuals, cross-sections, and the roles of lifespan and sex.relationships between persistent organic pollutant (pop) levels and age in wildlife biomonitoring are often interpreted as changes in contaminant burden as organisms age. however, cross-sectional body burden-age trends (cbats) obtained from biomonitoring studies, which sample individuals of different ages at the same time, should not be confused with longitudinal body burden-age trends (lbats) obtained by sampling the same individuals repeatedly through time. to clarify how cbats and lbats for w ...201424619475
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
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 ...201425048910
anisakids of seals found on the southern coast of baltic sea.in the present study 5 grey seals (halichoerus grypus), 3 common seals (phoca vitulina) and 1 ringed seal (pusa hispida) bycaught or stranded on the polish baltic sea coast in years 2000-2006 were investigated for the infestation of parasitic anisakid nematodes. 749 of anisakids were found. the most common were: contracaecum osculatum (59.3%) and pseudoterranova decipiens (31.0%). there were also small numbers of anisakis simplex (0.8%). after performing rflp three sibling species were found. c. ...201424570064
enantiomer-selective and quantitative trace analysis of selected persistent organic pollutants (pop) in traditional food from western greenland.enantiomeric fractions (ef) are today considered a powerful tool to elucidate selective uptake processes of chiral contaminants in biota. in this study, concentration levels and ef were determined by gas chromatograph-mass spectrometer (gc/ms) for α-hexachlorocyclohexane (α-hch) and trans-, cis-, and oxychlordane in selected greenlandic traditional food items, collected at the local market in nuuk in 2010. the food items selected were raw and smoked fish (salmon and halibut, n = 6), whale meat ( ...201424754396
temporal trends in "legacy" organochlorine contaminants in blubber of ringed seals (phoca hispida) from ulukhaktok, nt, canada between 1972 and 2010.in blubber of ringed seals (phoca hispida) from ulukhaktok, nt, residues of ddt, other organochlorine pesticides, and pcbs declined between 1972 and 2010. the rate of decline varied: concentrations of the ddt-group began to fall after 1981, whereas those of pcbs fell rapidly between 1972 and 1981, and then slowed. concentrations of cis- and trans-chlordane and of hcb in both sexes, and of cis-nonachlor in males, declined slowly between 1978 and 2010; those of other organochlorine pesticides rema ...201423955250
polychlorinated biphenyl profiles in ringed seals (pusa hispida) reveal historical contamination by a military radar station in labrador, canada.significant amounts of soil contaminated with polychlorinated biphenyls (pcbs) were discovered at a military radar station in saglek bay, labrador, canada, in 1996. subsequent work showed elevated pcb concentrations in local marine sediments, in the benthic-associated food web, and in some ringed seals (pusa hispida). the benthic-associated food web clearly reflected local pcb contamination, but the high pcb concentrations found in some ringed seals remained unexplained. in the present study, th ...201424273070
gross anatomy of the ringed seal (pusa hispida) gastro-intestinal tract.the gross anatomical structure of the ringed seal (pusa hispida) gastrointestinal tract is poorly described and often veterinary anatomical terminology is not used. although the basic abdominal visceral pattern corresponded to domestic carnivores, significant differences were noted. the stomach was an elongated sharply bent tube (u-shaped) with the pylorus and fundus juxtaposed. the elongated jejunum measured up to 15.6 times body length and had 37 jejunal arteries from the cranial mesenteric ar ...201423711331
demographic histories and genetic diversities of fennoscandian marine and landlocked ringed seal subspecies.island populations are on average smaller, genetically less diverse, and at a higher risk to go extinct than mainland populations. low genetic diversity may elevate extinction probability, but the genetic component of the risk can be affected by the mode of diversity loss, which, in turn, is connected to the demographic history of the population. here, we examined the history of genetic erosion in three fennoscandian ringed seal subspecies, of which one inhabits the baltic sea 'mainland' and two ...201425535558
satellite telemetry informs pcb source apportionment in a mobile, high trophic level marine mammal: the ringed seal (pusa hispida).marine mammals are typically poor indicators of point sources of environmental contaminants as a consequence of their often complex feeding ecologies and extensive movements, all of which mask the contributions of specific inputs. the release of polychlorinated biphenyls (pcbs) by a military radar station into saglek bay, labrador (canada) has contaminated marine sediments, bottom-feeding fish, seabirds, and some ringed seals, but attributing the pcbs in the latter highly mobile animals to this ...201425314596
pcb related effects thresholds as derived through gene transcript profiles in locally contaminated ringed seals (pusa hispida).causal evidence linking toxic injury to polychlorinated biphenyl (pcb) exposure is typically confounded by the complexity of real-world contaminant mixtures to which aquatic wildlife are exposed. a local pcb "hotspot" on the labrador coast provided a rare opportunity to evaluate the effects of pcbs on the health of a marine mammal as this chemical dominated their persistent organic pollutant (pop) burdens. the release of approximately 260 kg of pcbs by a military radar facility over a 30 year pe ...201425286162
causes and consequences of fine-scale population structure in a critically endangered freshwater seal.small, genetically uniform populations may face an elevated risk of extinction due to reduced environmental adaptability and individual fitness. fragmentation can intensify these genetic adversities and, therefore, dispersal and gene flow among subpopulations within an isolated population is often essential for maintaining its viability. using microsatellite and mtdna data, we examined genetic diversity, spatial differentiation, interregional gene flow, and effective population sizes in the crit ...201425005257
mrna expression of genes regulating lipid metabolism in ringed seals (pusa hispida) from differently polluted areas.there is a growing concern about the ability of persistent organic pollutants (pops) to influence lipid metabolism. although pops are found at high concentrations in some populations of marine mammals, for example in the ringed seal (pusa hispida) from the baltic sea, little is known about the effects of pops on their lipid metabolism. an optimal regulation of lipid metabolism is crucial for ringed seals during the fasting/molting season. this is a physiologically stressful period, during which ...201424334006
hg stable isotope time trend in ringed seals registers decreasing sea ice cover in the alaskan arctic.decadal time trends of mercury (hg) concentrations in arctic biota suggest that anthropogenic hg is not the single dominant factor modulating hg exposure to arctic wildlife. here, we present hg speciation (monomethyl-hg) and stable isotopic composition (c, n, hg) of 53 alaskan ringed seal liver samples covering a period of 14 years (1988-2002). in vivo metabolic effects and foraging ecology explain most of the observed 1.6 ‰ variation in liver δ(202)hg, but not δ(199)hg. ringed seal habitat use ...201526132925
enhanced biological processes associated with alopecia in polar bears (ursus maritimus).populations of wildlife species worldwide experience incidents of mass morbidity and mortality. primary or secondary drivers of these events may escape classical detection methods for identifying microbial insults, toxin exposure, or additional stressors. in 2012, 28% of polar bears sampled in a study in the southern beaufort sea region of alaska had varying degrees of alopecia that was concomitant with reduced body condition. concurrently, elevated numbers of sick or dead ringed seals were dete ...201526005754
local contamination, and not feeding preferences, explains elevated pcb concentrations in labrador ringed seals (pusa hispida).polychlorinated biphenyls (pcbs) in high trophic level species typically reflect the contributions of myriad sources, such that source apportionment is rarely possible. the release of pcbs by a military radar station into saglek bay, labrador contaminated the local marine food web. for instance, while heavier (higher chlorinated) pcb profiles in some ringed seals (pusa hispida) were previously attributed to this local source, differences in feeding preferences among seals could not be ruled out ...201525725460
mercury in the marine environment of the canadian arctic: review of recent findings.this review summarizes data and information which have been generated on mercury (hg) in the marine environment of the canadian arctic since the previous canadian arctic contaminants assessment report (cacar) was released in 2003. much new information has been collected on hg concentrations in marine water, snow and ice in the canadian arctic. the first measurements of methylation rates in arctic seawater indicate that the water column is an important site for hg methylation. arctic marine water ...201524953756
a novel tool to mitigate by-catch mortality of baltic seals in coastal fyke net fishery.developing methods to reduce the incidental catch of non-target species is important, as by-catch mortality poses threats especially to large aquatic predators. we examined the effectiveness of a novel device, a "seal sock", in mitigating the by-catch mortality of seals in coastal fyke net fisheries in the baltic sea. the seal sock developed and tested in this study was a cylindrical net attached to the fyke net, allowing the seals access to the surface to breathe while trapped inside fishing ge ...201525993534
amphibious hearing in ringed seals (pusa hispida): underwater audiograms, aerial audiograms and critical ratio measurements.ringed seals (pusa hispida) are semi-aquatic marine mammals with a circumpolar arctic distribution. in this study, we investigate the amphibious hearing capabilities of ringed seals to provide auditory profiles for this species across the full range of hearing. using psychophysical methods with two trained ringed seals, detection thresholds for narrowband signals were measured under quiet, carefully controlled environmental conditions to generate aerial and underwater audiograms. masked underwat ...201525987727
toxaphene in the aquatic environment of greenland.the octa- and nonachlorinated bornanes (toxaphene) chbs 26, 40, 41, 44, 50 and 62 were analysed in arctic char (salvelinus alpinus), shorthorn sculpin (myoxocephalus scorpius), ringed seal (pusa hispida) and black guillemot eggs (cepphus grylle) from greenland. despite their high trophic level, ringed seals had the lowest concentrations of these species, with a σ6toxaphene median concentration of 13-20 ng/g lipid weight (lw), suggesting metabolisation. the congener composition also suggests tran ...201525728301
(137)cs, (40)k and (210)po in marine mammals from the southern baltic sea.this study provides information on baseline concentrations of the radionuclides cesium-137, potassium-40 and polonium-210 in sea mammals from the baltic sea. the radionuclides were analyzed in the liver, kidney and muscle of harbor porpoises, striped dolphins, and gray and ringed seals from the polish coast by γ- and α-spectrometry. median (137)cs activities were 14.8, 13.2 and 23.2 bq kg(-1) w.w. in the liver, kidney and muscles, respectively. activities of (40)k and (210)po in the respective t ...201526456908
identifying foraging habitats of baltic ringed seals using movement data.identification of key foraging habitats of aquatic top predators is essential for designing effective management and conservation strategies. the baltic ringed seal (phoca hispida botnica) interacts with anthropogenic activities and knowledge of its spatial ecology is needed for planning population management and mitigating interactions with coastal fisheries. we investigated habitat use and foraging habitats of ringed seals (n = 26) with satellite telemetry in the northern baltic sea during aut ...201526401285
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