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Øystein Wiig - One of the best experts on this subject based on the ideXlab platform.
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The number and distribution of polar bears in the western Barents Sea
'Informa UK Limited', 2017Co-Authors: Jon Aars, Øystein Wiig, Tiago A. Marques, Karen Lone, Magnus Andersen, Ida Marie Bardalen Fløystad, Snorre B. Hagen, Stephen T. BucklandAbstract:Polar bears have experienced a rapid loss of sea-ice habitat in the Barents Sea. Monitoring this subpopulation focuses on the effects on polar bear demography. In August 2015, we conducted a survey in the Norwegian Arctic to estimate polar bear numbers and reveal population substructure. DNA profiles from biopsy samples and ear tags identified on photographs revealed that about half of the bears in Svalbard, compared to only 4.5% in the pack ice north of the archipelago, were recognized recaptures. The recaptured bears had originally been marked in Svalbard, mostly in spring. The existence of a local Svalbard stock, and another ecotype of bears using the pack ice in autumn with low likelihood of visiting Svalbard, support separate population size estimation for the two areas. Mainly by aerial survey line transect distance sampling methods, we estimated that 264 (95% CI = 199 – 363) bears were in Svalbard, close to 241 bears estimated for August 2004. The pack ice area had an estimated 709 bears (95% CI = 334 – 1026). The pack ice and the total (Svalbard + pack ice, 973 bears, 95% CI = 665 – 1884) both had higher estimates compared to August 2004 (444 and 685 bears, respectively), but the increase was not significant. There is no evidence that the fast reduction of sea-ice habitat in the area has yet led to a reduction in population size. The carrying capacity is likely reduced significantly, but recovery from earlier depletion up to 1973 may still be ongoing
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sea ice and polar bear den ecology at hopen island Svalbard
Marine Ecology Progress Series, 2011Co-Authors: Andrew E. Derocher, Øystein Wiig, Jon Aars, Magnus Andersen, Edmond Hansen, Martin BiuwAbstract:The maternity denning of polar bears Ursus maritimus was studied at Hopen Island, Svalbard, Norway, using information collected by direct observation and live-capture of females and cubs during den emergence in spring of 1994 to 2008. The number of maternity dens observed annually varied from 0 to 36. The arrival of sea ice at Hopen Island in autumn shifted from late October to mid-December during the period 1979 to 2010. Fewer maternity dens were found on Hopen Island in years when sea ice arrived later in the autumn. There were no significant differ- ences in body mass or litter size between female polar bears denning on Hopen Island and females caught elsewhere in Svalbard; however, females denning on Hopen Island were significantly younger than females denning elsewhere in Svalbard. Later arrival of sea ice in the autumn at Hopen Island was correlated with lower body mass of adult females and their cubs at emergence. The timing of arrival and departure of sea ice is highly variable but a trend of later arrival in autumn may be affecting the denning ecology of polar bears at the southern extent of their range in Svalbard.
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historical sex specific distribution of atlantic walrus odobenus rosmarus rosmarus in Svalbard assessed by mandible measurements
Polar Biology, 2007Co-Authors: Øystein Wiig, Erik W. Born, Ian Gjertz, Christian Lydersen, R StewartAbstract:We developed a discriminant function based on measurements of known-sex mandibles of walrus from the Canadian Arctic collected between 1983 and 1998 and used it to explore the sex ratio in the catches of walrus in Tusenoyane, south-eastern Svalbard, during the nineteenth century. Canadian mandibles older than 5 years of age of known sex were classified into correct sex with 100% accuracy by using two measurements. Applying the same discriminant function to 80 mandibles from Svalbard older than 5 years of age classified 48 (60%) as males and 32 (40%) as females. It also classified 584 aged and un-aged mandibles from Svalbard 67% (390) as males and 33% (194) as females. Eight of the aged jaws (10%) and 41 (7%) of the un-aged jaws had probabilities of classification into sex <80%. We stress the importance of being cautious in applying a discriminant function developed from Canadian mandibles to classify the sex of old weathered mandibles from Svalbard. However, we believe our results indicate that female walrus were once more common in south-eastern Svalbard than they are now.
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postnatal growth in body length and mass of polar bears ursus maritimus at Svalbard
Journal of Zoology, 2002Co-Authors: Andrew E. Derocher, Øystein WiigAbstract:The von Bertalanffy curve was used to examine growth patterns in both body length and mass of female and male polar bears Ursus maritimus live-captured near Svalbard, Norway. A longer growth period in males resulted in pronounced sexual dimorphism in both body length and mass. Males were 1.16 times longer and 2.10 times heavier than females. The asymptotic body length of female and male polar bears from Svalbard was smaller than that for polar bears in four of six previously studied populations. Asymptotic body mass of females from Svalbard was lower than other previously studied populations, while males were generally lighter. The reasons for the lighter bears in Svalbard are unclear, but we believe they were not related to sampling error, ecosystem productivity, or genetic differences. The high pollution load of polar bears in Svalbard may have affected body size but this potential factor could not be assessed. The generally smaller size of polar bears in Svalbard was consistent with density-dependent growth effects but again, information on population density relative to carrying capacity was insufficient to assess this hypothesis.
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Migration of Walruses (Odobenus rosmarus) in the Svalbard and Franz Josef Land area
Journal of Zoology, 1996Co-Authors: Øystein Wiig, Ian Gjertz, David GriffithsAbstract:Thirty-four walruses (Odobenus rosmarus) were fitted with satellite transmitters (PTTs) from 1990 to 1993 in order to study the distribution of the population in the Svalbard area. Twenty-eight were caught at Svalbard and six at Franz Josef Land. All were males except one female caught at Franz Josef Land. At Svalbard, one walrus was caught on the west coast of Spitsbergen, while the others were caught at southern Edgeoya. All walruses were caught in the period from mid-July to early September. The PTTs provided information on location for periods ranging from 0 to 212 days. The results of the satellite trackings show that there is a migration of male walruses between most of the walrus areas at Svalbard and Franz Josef Land. In particular, it seems that migration of males from southern Edgeoya to Kvitoya, Viktoria Island, and Franz Josef Land is common. The walruses winter in the southern parts of Svalbard, as well as within the winter pack-ice of north-eastern Svalbard, which contains numerous open leads. The only walrus at Franz Josef Land that was followed to mid-winter stayed in the area and therefore supports the view that walruses also winter in that area. It is assumed that the majority of walruses at Svalbard are males from one common Svalbard-Franz Josef Land stock. The walrus in the Svalbard-Franz Josef Land area today belong to a recovering population. Their current distribution and behaviour may therefore differ from that found in Svalbard in former times.
Ian Gjertz - One of the best experts on this subject based on the ideXlab platform.
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historical sex specific distribution of atlantic walrus odobenus rosmarus rosmarus in Svalbard assessed by mandible measurements
Polar Biology, 2007Co-Authors: Øystein Wiig, Erik W. Born, Ian Gjertz, Christian Lydersen, R StewartAbstract:We developed a discriminant function based on measurements of known-sex mandibles of walrus from the Canadian Arctic collected between 1983 and 1998 and used it to explore the sex ratio in the catches of walrus in Tusenoyane, south-eastern Svalbard, during the nineteenth century. Canadian mandibles older than 5 years of age of known sex were classified into correct sex with 100% accuracy by using two measurements. Applying the same discriminant function to 80 mandibles from Svalbard older than 5 years of age classified 48 (60%) as males and 32 (40%) as females. It also classified 584 aged and un-aged mandibles from Svalbard 67% (390) as males and 33% (194) as females. Eight of the aged jaws (10%) and 41 (7%) of the un-aged jaws had probabilities of classification into sex <80%. We stress the importance of being cautious in applying a discriminant function developed from Canadian mandibles to classify the sex of old weathered mandibles from Svalbard. However, we believe our results indicate that female walrus were once more common in south-eastern Svalbard than they are now.
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Body size of male Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard
Journal of Zoology, 1996Co-Authors: ø. Whg, Ian GjertzAbstract:Morphometric data are given for 41 adult male Atlantic walruses (Odobenus rosmarus rosmarus) immobilized at Svalbard. Total body weight ranged from 960 to 1450 kg. Standard body length ranged from 258 to 380 cm, while curvilinear tusk length ranged from 17 to 65 cm. Immobilized animals were selected for their large size. The sample is therefore biased towards larger animals. Based on regression equations developed for walruses caught in Greenland, the weights of Svalbard walruses were estimated from standard body length and axillary girth. Estimated weights ranged from 632 to 1883 kg. The present data suggest that Atlantic walruses at Svalbard can attain the same body size as Pacific (O. r. divergens) and Laptev walruses (O. r. laptevi).
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Migration of Walruses (Odobenus rosmarus) in the Svalbard and Franz Josef Land area
Journal of Zoology, 1996Co-Authors: Øystein Wiig, Ian Gjertz, David GriffithsAbstract:Thirty-four walruses (Odobenus rosmarus) were fitted with satellite transmitters (PTTs) from 1990 to 1993 in order to study the distribution of the population in the Svalbard area. Twenty-eight were caught at Svalbard and six at Franz Josef Land. All were males except one female caught at Franz Josef Land. At Svalbard, one walrus was caught on the west coast of Spitsbergen, while the others were caught at southern Edgeoya. All walruses were caught in the period from mid-July to early September. The PTTs provided information on location for periods ranging from 0 to 212 days. The results of the satellite trackings show that there is a migration of male walruses between most of the walrus areas at Svalbard and Franz Josef Land. In particular, it seems that migration of males from southern Edgeoya to Kvitoya, Viktoria Island, and Franz Josef Land is common. The walruses winter in the southern parts of Svalbard, as well as within the winter pack-ice of north-eastern Svalbard, which contains numerous open leads. The only walrus at Franz Josef Land that was followed to mid-winter stayed in the area and therefore supports the view that walruses also winter in that area. It is assumed that the majority of walruses at Svalbard are males from one common Svalbard-Franz Josef Land stock. The walrus in the Svalbard-Franz Josef Land area today belong to a recovering population. Their current distribution and behaviour may therefore differ from that found in Svalbard in former times.
Christian Brochmann - One of the best experts on this subject based on the ideXlab platform.
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an arctic community of symbiotic fungi assembled by long distance dispersers phylogenetic diversity of ectomycorrhizal basidiomycetes in Svalbard based on soil and sporocarp dna
Journal of Biogeography, 2012Co-Authors: Christian Brochmann, Jozsef Geml, Ina Timling, Clare H Robinson, Niall Lennon, Chad H Nusbaum, Machiel E Noordeloos, Lee D TaylorAbstract:Aim Current evidence from temperate studies suggests that ectomycorrhizal (ECM) fungi require overland routes for migration because of their obligate symbiotic associations with woody plants. Despite their key roles in arctic ecosystems, the phylogenetic diversity and phylogeography of arctic ECM fungi remains little known. Here we assess the phylogenetic diversity of ECM communities in an isolated, formerly glaciated, high arctic archipelago, and provide explanations for their phylogeographic origins. Location Svalbard. Methods We generated and analysed internal transcribed spacer (ITS) nuclear ribosomal DNA sequences from both curated sporocarp collections (from Svalbard) and soil polymerase chain reaction (PCR) clone libraries (from Svalbard and the North American Arctic), compared these with publicly available sequences in GenBank, and estimated the phylogenetic diversity of ECM fungi in Svalbard. In addition, we conducted coalescent analyses to estimate migration rates in selected species. Results Despite Svalbard’s geographic isolation and arctic climate, its ECM fungi are surprisingly diverse, with at least 72 non-singleton operational taxonomic units (soil) and 109 phylogroups (soil + sporocarp). The most species-rich genera are Thelephora/Tomentella, Cortinarius and Inocybe, followed by Hebeloma, Russula, Lactarius, Entoloma, Sebacina, Clavulina, Laccaria, Leccinum and Alnicola. Despite the scarcity of available reference data from other arctic regions, the majority of the phylogroups (73.4%) were also found outside Svalbard. At the same time, all putative Svalbard ‘endemics’ were newly sequenced taxa from diverse genera with massive undocumented diversity. Overall, our results support long-distance dispersal more strongly than vicariance and glacial survival. However, because of the high variation in nucleotide substitution rates among fungi, allopatric persistence since the Pliocene, although unlikely, cannot be statistically rejected. Results from the coalescent analyses suggest recent gene flow among different arctic areas. Main conclusions Our results indicate numerous recent colonization events and suggest that long-distance, transoceanic dispersal is widespread in arctic ECM fungi, which differs markedly from the currently prevailing view on the dispersal capabilities of ECM fungi. Our molecular evidence indicates that long-distance dispersal has probably played a major role in the phylogeographic history of some ECM fungi in the Northern Hemisphere. Our results may have implications for studies on the biodiversity, ecology and conservation of arctic fungi in general.
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clonality and recombination in the arctic plant saxifraga cernua
Botanical Journal of the Linnean Society, 2006Co-Authors: Siri Kjolner, Sigurd M Sastad, Christian BrochmannAbstract:The circumarctic clonal plant Saxifraga cernua reproduces efficiently via bulbils, largely depends on insects for pollination and appears to set seed very rarely. However, high levels of genotypic variation observed at small spatial scales in the arctic archipelago of Svalbard have been taken as evidence of occasional sexual reproduction. Here we assess the relative contributions of mutation and recombination to random amplified polymorphic DNA variation in four populations in East Greenland and re-analyse the Svalbard data. Greater variation due to recombination was predicted in Greenland than in Svalbard, because the higher summer temperatures and longer growing season likely increase the chances for sexual reproduction. Although we observed higher levels of genotypic diversity in Greenland than in Svalbard, matrix incompatibility and linkage disequilibrium measures provided no evidence of more sexuality, suggesting differences in glacial/postglacial history. The genetic structure and spatial distribution of clones suggest that clonal migration may increase variability in local populations, which is consistent with frequent large-scale migration in this species inferred from a circumarctic analysis of chloroplast DNA haplotypes. We conclude that a combination of somatic mutations and sexual reproduction has contributed to the observed patterns of genotypic diversity in the Greenland and Svalbard populations of S. cernua, and that sexual reproduction is important in maintaining genotypic diversity, despite the rarity of observations of seed setting. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 152, 209–217.
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conservation genetics and population history of betula nana vaccinium uliginosum and campanula rotundifolia in the arctic archipelago of Svalbard
Arctic Antarctic and Alpine Research, 2002Co-Authors: Inger Greve Alsos, Torstein Engelskjon, Christian BrochmannAbstract:Plant species defined as strongly thermophilous in Svalbard are rare and may be threatened by extinction due to suppressed sexual reproduction, small population sizes, genetic depauperation, and human activity. We examined isozyme diversity in three of these species-Betula nana, Vaccinium uliginosum, and Campanula rotundifolia-in Svalbard. Twenty-five to 60 ramets from each of two to three (sub)populations of each species were analyzed for eight enzyme systems. In B. nana, genetic diversity was low within sampling plots (D: 0.00-0.49) and intermediate within populations (mean D = 0.70, mean Hep = 0.119). Genetic diversity at the species level (Hes) was 0.141, and the differentiation among populations (FsT = 0.193) was higher than the average for other species with similar life traits. In V. uliginosum, no variation was observed within plots, and genetic diversity within populations was low (mean D = 0.29, mean Hep = 0.082). Genetic diversity at the species level was also low (Hes = 0.152), and the differentiation among populations (FsT = 0.493) was much higher than in most other species studied. The only Svalbard population of C. rotundifolia has 2n = 34 and is traditionally considered as diploid, but the observed enzyme banding patterns suggest polyploidy. In this species, genotypic diversity was low within plots (D: 0.00-0.33), intermediate within subpopulations (mean D = 0.74), and all multilocus phenotypes were local. The present populations of all three species in Svalbard are probably fragmented relics of larger populations in the postglacial warm period. On the basis of the observed distribution of genetic diversity and population sizes, we propose to conserve all Svalbard populations of V. uliginosum and C. rotundifolia, and at least one population of B. nana.
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glacial survival does not matter ii rapd phylogeography of nordic saxifraga cespitosa
Molecular Ecology, 1998Co-Authors: Mari Mette Tollefsrud, K Bachmann, Kjetill S Jakobsen, Christian BrochmannAbstract:It has been suggested that many arctic-alpine plant species have limited dispersal ability and cannot have arrived in Scandinavia and the arctic archipelago of Svalbard by long-distance dispersal after a total glaciation. It has therefore been proposed that such species must have survived the entire glaciation(s) in ice-free refugia in southern Norway, northern Norway and Svalbard. We investigated random amplified polymorphic DNA (RAPD) variation among 28 populations from Norway and Svalbard of one of these arctic-alpine ‘short-distance dispersers’, the selfing polyploid Saxifraga cespitosa. In an analysis of molecular variance (AMOVA), more variation was found among populations within the three postulated refugia regions (45%) than among these regions (25%). Spatial autocorrelation (Mantel) analyses showed that the genetic distance monotonously increased with increasing geographical distance. In UPGMA and PCO analyses, the populations from Norway and Svalbard formed a south–north cline that continued across the Barents Sea barrier. The results suggest that there has been recent dispersal among the three postulated refugia regions and thus that postglacial dispersal into these refugia regions from other distant areas also must represent a possibility. The observed geographical pattern of the genetic variation may have been established after expansion from different source areas outside the North European ice sheet and/or from different refugia areas ‘within’ the ice sheet, but it is probably not possible to distinguish among these alternatives. The results for S. cespitosa are consistent with a dynamic late- and postglacial scenario with extensive plant dispersal, and support the conclusion from our previous study of the outbreeding Saxifraga oppositifolia; the hypothesis of glacial survival in Norway and/or Svalbard is superfluous.
Hans O Portner - One of the best experts on this subject based on the ideXlab platform.
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effects of ocean acidification and warming on the larval development of the spider crab hyas araneus from different latitudes 54 vs 79 n
Marine Ecology Progress Series, 2010Co-Authors: Kathleen Walther, Klaus Anger, Hans O PortnerAbstract:The combined effects of predicted ocean acidification and global warming on the larvae of the cold-eurythermal spider crab Hyas araneus L. were investigated in 2 populations: a southern-most around Helgoland (North Sea, 54 degrees N) and a northernmost at Svalbard (North Atlantic, 79 degrees N). Larvae were exposed at temperatures of 3, 9 and 15 degrees C to present day normocapnia (380 ppm CO(2)) and to CO(2) conditions predicted for the near or medium-term future (710 ppm by the year 2100, 3000 ppm by 2300 and beyond). Larval development time, growth and C/N ratio were studied in the larval stages Zoea I, II, and Megalopa. Permanent differences in instar duration between both populations were detected in all stages, likely as a result of evolutionary temperature adaptation. With the exception of Zoea II at 3 degrees C and under all CO(2) conditions, development in all instars from Svalbard was delayed compared to those from Helgoland. Most prominently, development was much longer and fewer specimens morphosed to the first crab instar in the Megalopa from Svalbard than from Helgoland. Enhanced CO(2) levels (particularly 3000 ppm) extended the duration of larval development and reduced larval growth (measured as dry mass) and fitness (decreasing C/N ratio, a proxy of the lipid content). Such effects were strongest in the zoeal stages of Svalbard larvae, and during the Megalopa instar of Helgoland larvae. The high sensitivity of megalopae from the Svalbard population to warming and of those from Helgoland to enhanced CO(2) levels suggests that this larval instar is a physiologically sensitive bottleneck within the life cycle of H. araneus.
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effects of ocean acidification and warming on the larval development of the spider crab hyas araneus from different latitudes 54 vs 79 n
Marine Ecology Progress Series, 2010Co-Authors: Kathleen Walther, Klaus Anger, Hans O PortnerAbstract:The combined effects of predicted ocean acidification and global warming on the larvae of the cold-eurythermal spider crab Hyas araneus L. were investigated in 2 populations: a southern-most around Helgoland (North Sea, 54 degrees N) and a northernmost at Svalbard (North Atlantic, 79 degrees N). Larvae were exposed at temperatures of 3, 9 and 15 degrees C to present day normocapnia (380 ppm CO(2)) and to CO(2) conditions predicted for the near or medium-term future (710 ppm by the year 2100, 3000 ppm by 2300 and beyond). Larval development time, growth and C/N ratio were studied in the larval stages Zoea I, II, and Megalopa. Permanent differences in instar duration between both populations were detected in all stages, likely as a result of evolutionary temperature adaptation. With the exception of Zoea II at 3 degrees C and under all CO(2) conditions, development in all instars from Svalbard was delayed compared to those from Helgoland. Most prominently, development was much longer and fewer specimens morphosed to the first crab instar in the Megalopa from Svalbard than from Helgoland. Enhanced CO(2) levels (particularly 3000 ppm) extended the duration of larval development and reduced larval growth (measured as dry mass) and fitness (decreasing C/N ratio, a proxy of the lipid content). Such effects were strongest in the zoeal stages of Svalbard larvae, and during the Megalopa instar of Helgoland larvae. The high sensitivity of megalopae from the Svalbard population to warming and of those from Helgoland to enhanced CO(2) levels suggests that this larval instar is a physiologically sensitive bottleneck within the life cycle of H. araneus.
Kit M. Kovacs - One of the best experts on this subject based on the ideXlab platform.
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walrus odobenus rosmarus research in Svalbard norway 2000 2010
Nammco Scientific Publications, 2013Co-Authors: Christian Lydersen, Kit M. KovacsAbstract:Herein we report results from studies on walruses in Svalbard conducted in 2000-2010. Data from newly developed satellite relay data loggers (SRDLs) revealed seasonal differences in habitat use of adult male walruses. During winter, they moved into areas of >90% ice concentration, traveling as far as 600 km from ice-free water. Breeding areas deep into the pack ice were identified based on timing of the occupancy and diving behaviour. When the breeding season was over, walruses with SRDLs that were still transmitting locations returned to the coast, showing high site fidelity to the previous year’s summering area. Haul-out data from the SRDLs provided correction factors for an aerial survey of walruses that covered all known haul-out sites within the Svalbard Archipelago. This survey estimated 2,629 (95 % CI; 2,318 – 2,998) walruses to be in Svalbard during August 2006. Blubber biopsies from adult male walruses analyzed for fatty acids (FAs) showed vertical stratification similar to that observed in many other marine mammals. However, differences between layers were less pronounced, possibly because the thick dermis of walruses provides an insulating shield, affecting the FA composition of the outer blubber. The FA composition of the inner blubber most closely resembled the lipids in Mya truncata and Buccinum spp., which are considered the most important walrus prey in Svalbard. A study investigating the use of skin biopsies for assessing levels of organochlorines (OCs) in walruses found a significant relationship between OC levels in skin and blubber. Another contaminant study found a significant decrease in levels of PCBs and DDE in walruses in Svalbard from 1993 to 2002-04. Large inter-individual variation in OC levels was found, although all of the study animals were adult males from roughly the same location. In FA analyses of the inner blubber this variation appeared to be diet-related, with high OC levels having FA compositions in the inner blubber that closely matched seal tissues, while those with low levels matched typical invertebrate prey. Various enzymes, proteins, metabolites, minerals, and hormones were measured in blood samples to serve as baseline data for future health-related studies of both wild and captive walruses. Historical sex-distribution of walruses in southern Svalbard was investigated based on mandible measurements of individuals hunted during the 19 th century. The analyses showed that female walruses were once more common in south-eastern Svalbard than they are today.
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levels of toxaphene congeners in white whales delphinapterus leucas from Svalbard norway
Science of The Total Environment, 2006Co-Authors: G Andersen, Christian Lydersen, Siri Foreid, Janneche Utne Skaare, Bjorn Munro Jenssen, Kit M. KovacsAbstract:This study reports concentrations of three pesticide toxaphene congeners (CHBs; CHB-26, -50 and -62) from the blubber of ten adult, male white whales (Delphinapterus leucas) from Svalbard, Norway. The CHB congeners that occurred at the highest levels in the blubber of the white whales were, as expected, CHB-26 (4636F1992 (SD) ng/g l.w.) and CHB-50 (6579F2214 ng/g l.w.); CHB-62 (232F231 ng/g l.w.) was also present, but at much lower concentrations. The mean level of the sum of the three CHBs (ACHBs=11,447F4208 ng/g l.w.) in this study is more than twice the mean concentrations of the well-known organochlorine (OC) pollutants ADDTs (sum of ppV-DDT, ppV-DDE, ppV-DDD) and APCBs (sum of 27 PCB congeners) previously reported from the same individual white whales. The concentrations of CHBs in white whales from Svalbard are at the high end of the range for concentrations of these compounds compared to other Arctic white whale populations. Additionally, the contribution of CHBs to the overall OC burden is larger in white whales from Svalbard compared with their counterparts from other areas in the Arctic. Male white whales from Svalbard have several orders of magnitude higher concentrations of ACHBs compared to seals and polar bears (Ursus maritimus) from the same area. The high levels of CHBs in these whales, and their dominance in the OC pattern, suggests that white whales in Svalbard are exposed to high levels of this group of contaminants. Further studies are needed to investigate possible effects of CHBs and other OC contaminants on the white whale population in Svalbard. D 2005 Published by Elsevier B.V.
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accumulation and lactational transfer of pcbs and pesticides in harbor seals phoca vitulina from Svalbard norway
Science of The Total Environment, 2004Co-Authors: Hans Wolkers, Christian Lydersen, Kit M. KovacsAbstract:Abstract The harbor seal population on Svalbard, the northernmost breeding site for this species, appears to have a truncated age distribution with older animals being largely absent. PCBs and pesticides were measured in harbor seal males, females, milk and pups from Svalbard to explore whether contaminant exposure or accumulation is a possible cause of premature death for these animals. The levels and patterns of these contaminants were assessed. In addition, transfer of these compounds from females to their pups during lactation was assessed. Both PCB and pesticide levels were low compared to more southern harbor seal populations. Animals from Svalbard contained 5–10 times lower contaminant levels, compared to seals from the Norwegian mainland, and 30 times lower concentrations than those of harbor seals from the Gulf of St. Lawrence in eastern Canada. Ringed seals from Svalbard have contaminant levels that are comparable to the harbor seals, probably because the diet, as well as the metabolic capacity, of the two species is similar at this location. The findings of this study indicate that the early mortality observed for harbor seals on Svalbard, is not likely to be due to contaminant exposure. Female harbor seals transfer a modified contaminant mixture to their pups compared to that found within their own tissues; compounds with higher log K ow , such as some penta-chlorinated PCBs, were selectively transferred into milk. As a result, the contaminant pattern between males and females differed, with penta-chlorinated PCBs more abundant in males than in females. In addition, pups receive a relatively high amount of the less lipophylic compounds and a low amount of the more lipophylic compounds. The similar contaminant pattern in milk and pups suggested that they are probably unable to metabolize contaminants and consequently, accumulate all ingested chemicals.
