Sea ice reduction drives genetic differentiation among Barents Sea polar bears

Loss of Arctic sea ice owing to climate change is predicted to reduce both genetic diversity and gene flow in ice-dependent species, with potentially negative consequences for their long-term viability. Here, we tested for the population-genetic impacts of reduced sea ice cover on the polar bear (Ursus maritimus) sampled across two decades (1995–2016) from the Svalbard Archipelago, Norway, an area that is affected by rapid sea ice loss in the Arctic Barents Sea. We analysed genetic variation at 22 microsatellite loci for 626 polar bears from four sampling areas within the archipelago. Our results revealed a 3–10% loss of genetic diversity across the study period, accompanied by a near 200% increase in genetic differentiation across regions. These effects may best be explained by a decrease in gene flow caused by habitat fragmentation owing to the loss of sea ice coverage, resulting in increased inbreeding of local polar bears within the focal sampling areas in the Svalbard Archipelago. This study illustrates the importance of genetic monitoring for developing adaptive management strategies for polar bears and other ice-dependent species

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This study was funded by the Norwegian Ministry of Climate and the Environment. TAM is grateful for partial support by Centro de Estatística e Aplicações da Universidade de Lisboa, funded by the Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013.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 = 334 - 1026) 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.Publisher PDFPeer reviewe

DNA-overvåking av brunbjørn i Karasjok 2020 ved bruk av hårfeller

DNA-overvåking av brunbjørn i et totalt 650 km2 stort område i Karasjok kommune i Troms og Finnmark ble utført med hårfeller med luktstoff i 2 måneder fra juni til august i 2020. Overvåkingen ble utført i tre deler; et hårfelleprosjekt sentralt i Karasjok, et hårfelleprosjekt i Anàrjohka og et hårfelleprosjekt utført av et elgjaktlag i jaktfelt 28. Vi brukte et 5 x 5 km rutesystem med totalt 26 ruter med én hårfelle i hver rute, og der hårfellen ble flyttet etter en måned til en annen lokalitet i samme rute. I tillegg var to hårfeller plassert på geografiske punkt av elgjaktlag i 2 uker. Det ble samlet inn til sammen 58 hårprøver fra hårfellene (i tillegg til 9 ekskrementprøver). For de 16 hårfellene sentralt plassert i Karasjok var 24 av de 48 innsamlede prøvene (50 %) positive for brunbjørn i DNA-analysen ved laboratoriet på NIBIO Svanhovd. Fra disse prøvene ga 22 prøver en fullstendig identifiserende DNA-profil som viste 8 ulike bjørner (3 hannbjørn og 5 hunnbjørn). Bjørnetettheten ble estimert til 0,20 bjørn/10km2 som er i samsvar med forrige år. Totalt ble det funnet 11 ulike bjørneindivider (5 hannbjørn og 6 hunnbjørn) for de 3 hårfelleprosjektene. Av disse 11 var 9 bjørner tidligere påvist, mens 2 av bjørnene (2 hannbjørner) var nye. Hårfelleprosjektetene bidrar med unik geografisk og tidsmessig informasjon om bjørneaktivitenen i området, og 4 av de 11 påviste bjørnene var i 2020 kun påvist igjennom hårfelleprosjektene.publishedVersio

DNA-overvåking av brunbjørn i Tana 2023 ved bruk av hårfeller

Hår fra brunbjørn ble samlet inn i 20 hårfeller med luktstoff i et 500 km2 stort område i Tana kommune (Troms og Finnmark fylke) i løpet av 2 måneder fra juni til august i 2023. Det ble brukt et 5 x 5 km rutesystem med én hårfelle i hver rute, og der hårfellen ble flyttet etter én måned til en annen lokalitet i samme rute. Hårrøttene ble DNA-analysert med 8 genetiske markører for individbestemmelse, i tillegg til en kjønnsbestemt markør. Totalt ble det samlet inn 48 hårprøver (i tillegg til 3 ekskrementprøver). Av de innsamlede hårprøvene var 27 (56 %) positive for brunbjørn. Ingen av ekskrementprøvene ga treff på DNA fra brunbjørn. Det ble påvist 4 ulike bjørner (2 hannbjørner og 2 hunnbjørner). Av disse 4 bjørnene var alle tidligere identifiserte individer, og gir en bjørnetetthet på 0,08 bjørn/10km2. Det ble påvist flere bjørner i første halvdel (juni-juli) enn i andre halvdel (juli-august) av prosjektet. Hårfellemetoden med DNA-analyse av hårrøtter har i dette arbeidet gitt unik geografisk og tidsmessig informasjon om brunbjørn i det undersøkte området.DNA-overvåking av brunbjørn i Tana 2023 ved bruk av hårfellerpublishedVersio

Mah-jongsett fra Øst Asia : Med fokus på sprekkdannelse i bambus

Denne oppgaven tar for seg konserveringen av et mah-jongsett tilhørende Kulturhistorisk museum, og undersøkelser rundt oppsprekking av bambus. Mah-jongsettet ble trolig produsert på begynnelsen av 1900 tallet, og består av flere separate deler. Sette består av 148 brikker i bambus og ben, brett til oppbevaring av brikkene i papp trukket med tekstil og en eske av lær. Alle materialene ble undersøkt og identifisert ved hjelp av metoder som mikroskopi, XRF og FTIR. Flere av materialene var nedbrutt og krevde derfor konservering. Konserveringen innebar rensing av ben og tekstil, forsterkning av papp, reparasjon av flenger i tekstil og reparasjon av skader i hjørnene både på brett og eske. Hovedfokuset for oppgaven har vært oppsprekking av bambus. Oppsprekking ble observert langs skjøten mellom bambus og ben. Det ble valgt å se nærmere på hvordan denne type skjøte kan påvirke materialene, når utsatt for svingninger i RF. I den forbindelse ble et eksperiment utført med testbrikker, for å fremskynde oppsprekking i bambusen. Dette for å undersøke hvor det ville oppstå oppsprekking, under ekstreme forhold

An analysis of the population structure of white whales (Delphinapterus leucas) in Svalbard

White whales are found all around Svalbard, but their population structure in this area is unknown. A recent study using telemetry showed that the animals tagged in the Van Keulen/Van Mijenfjorden and Storfjorden in the southern parts of Svalbard only travelled in the southern areas of Svalbard. Because they never migrated to the northern parts of Svalbard this could indicate two or more separated sub-populations of white whales in the Svalbard waters. The aim of the present study was to analyze the population structure of the white whales around Svalbard by using molecular markers (the D-loop region of the mitochondrial DNA and seven microsatellite loci). This was done by comparing individual whales mainly from Krossfjorden in the northwestern part of Svalbard with individuals from Storfjorden in the southeastern parts of Svalbard to see if there are significant differences in the allele frequencies and haplotypes from these two regions. An analysis of molecular variance (AMOVA) based on the mitochondrial haplotypes showed a higher variation within the sample areas (96.79 %) than between the sample areas (3.21 %). The program STRUCTURE did not detect any structuring of the samples based on the seven microsatellite loci, and found just one cluster of individuals (K=1) most likely. A significant differentiation (FST) between the two sample locations was found for both the mitochondrial haplotypes (FST = 0.119, P < 0.0001) and the microsatellite loci (FST = 0.01551, P = 0.01802 +/- 0.0121), but due to the small sample size, matrilineal pod structure and other deviations from the underlying assumptions this was only used as descriptors. A minimum spanning tree indicated some clustering of the mitochondrial haplotypes but these clustering did not correspond to the sample locations. A gender segregation of habitat use was found, as the Krossfjorden area was used mainly by all male groups. From the current results it seems that the studied part of Svalbard only contains one population. However, further analyses with more samples covering more areas of Svalbard and more loci are advised. Also the gene-flow and possible mixing of whales with the Karskaya population in the western Russian Arctic should be addressed

Monitoring of the Apple Fruit Moth: Detection of Genetic Variation and Structure Applying a Novel Multiplex Set of 19 STR Markers

The apple fruit moth Argyresthia conjugella (Lepidoptera, Yponomeutidae) is a seed predator of rowan (Sorbus aucuparia) and is distributed in Europe and Asia. In Fennoscandia (Finland, Norway and Sweden), rowan fruit production is low every 2–4 years, and apple (Malus domestica) functions as an alternative host, resulting in economic loss in apple crops in inter-mast years. We have used Illumina MiSeq sequencing to identify a set of 19 novel tetra-nucleotide short tandem repeats (STRs) in Argyresthia conjugella. Such motifs are recommended for genetic monitoring, which may help to determine the eco-evolutionary processes acting on this pest insect. The 19 STRs were optimized and amplified into five multiplex PCR reactions. We tested individuals collected from Norway and Sweden (n = 64), and detected very high genetic variation (average 13.6 alleles, He = 0.75) compared to most other Lepidoptera species studied so far. Spatial genetic differentiation was low and gene flow was high in the test populations, although two non-spatial clusters could be detected. We conclude that this set of genetic markers may be a useful resource for population genetic monitoring of this economical important insect species.publishedVersio

Large-scale genetic admixture suggests high dispersal in an insect pest, the apple fruit moth

Knowledge about population genetic structure and dispersal capabilities is important for the development of targeted management strategies for agricultural pest species. The apple fruit moth, Argyresthia conjugella (Lepidoptera, Yponomeutidae), is a pre-dispersal seed predator. Larvae feed on rowanberries (Sorbus aucuparia), and when rowanberry seed production is low (i.e., inter-masting), the moth switches from laying eggs in rowanberries to apples (Malus domestica), resulting in devastating losses in apple crops. Using genetic methods, we investigated if this small moth expresses any local genetic structure, or alternatively if gene flow may be high within the Scandinavian Peninsula (~850.000 km2, 55o - 69o N). Genetic diversity was found to be high (n = 669, mean He = 0.71). For three out of ten tetranucleotide STRs, we detected heterozygote deficiency caused by null alleles, but tests showed little impact on the overall results. Genetic differentiation between the 28 sampling locations was very low (average FST = 0.016, P < 0.000). Surprisingly, we found that all individuals could be assigned to one of two non-geographic genetic clusters, and that a third, geographic cluster was found to be associated with 30% of the sampling locations, with weak but significant signals of isolation-by-distance. Conclusively, our findings suggest wind-aided dispersal and spatial synchrony of both sexes of the apple fruit moth over large areas and across very different climatic zones. We speculate that the species may recently have had two separate genetic origins caused by a genetic bottleneck after inter-masting, followed by rapid dispersal and homogenization of the gene pool across the landscape. We suggest further investigations of spatial genetic similarities and differences of the apple fruit moth at larger geographical scales, through life-stages, across inter-masting, and during attacks by the parasitoid wasp (Microgaster politus).publishedVersio

Large-scale genetic admixture suggests high dispersal in an insect pest, the apple fruit moth

Knowledge about population genetic structure and dispersal capabilities is important for the development of targeted management strategies for agricultural pest species. The apple fruit moth, Argyresthia conjugella (Lepidoptera, Yponomeutidae), is a pre-dispersal seed predator. Larvae feed on rowanberries (Sorbus aucuparia), and when rowanberry seed production is low (i.e., inter-masting), the moth switches from laying eggs in rowanberries to apples (Malus domestica), resulting in devastating losses in apple crops. Using genetic methods, we investigated if this small moth expresses any local genetic structure, or alternatively if gene flow may be high within the Scandinavian Peninsula (~850.000 km2, 55o - 69o N). Genetic diversity was found to be high (n = 669, mean He = 0.71). For three out of ten tetranucleotide STRs, we detected heterozygote deficiency caused by null alleles, but tests showed little impact on the overall results. Genetic differentiation between the 28 sampling locations was very low (average FST = 0.016, P < 0.000). Surprisingly, we found that all individuals could be assigned to one of two non-geographic genetic clusters, and that a third, geographic cluster was found to be associated with 30% of the sampling locations, with weak but significant signals of isolation-by-distance. Conclusively, our findings suggest wind-aided dispersal and spatial synchrony of both sexes of the apple fruit moth over large areas and across very different climatic zones. We speculate that the species may recently have had two separate genetic origins caused by a genetic bottleneck after inter-masting, followed by rapid dispersal and homogenization of the gene pool across the landscape. We suggest further investigations of spatial genetic similarities and differences of the apple fruit moth at larger geographical scales, through life-stages, across inter-masting, and during attacks by the parasitoid wasp (Microgaster politus).publishedVersio

Undersøkelse av antibiotikaresistensmarkørgenet nptII i norsk natur. Analyserapport: Forekomst av antibiotikaresistensmarkørgenet neomycin fosfotransferase II (nptII) i prøver fra 12 ville arter fra Norge

Undersøkelse av antibiotikaresistensmarkørgenet neomycin fosfotransferase II (nptII) i prøver fra 12 ville arter fra Norge I et prosjekt fra Miljødirektoratet har vi testa for tilstedeværelse av nptII genet i 219 prøver fra 12 ulike ville arter fra hele Norge. Utvalget av prøver inkluderte planter (løvetann, rødkløver og markjordbær), insekter (skogmaur, rognebærmøll og liten høstmåler), snegl (brunsnegl), fisk (ørret og rognkjeks) og pattedyr (rødrev, brunbjørn og isbjørn). Vi brukte to ulike sanntids-PCR (Real-Time-PCR) tester for å undersøke fo tilstedeværelsen av kopier av nptII-genet i de 219 prøvene. Vi fant at nesten alle prøvene var negative (99%), mens kun tre enkeltprøver (løvetann, rødkløver og skogmaur) viste et svært lavt nivå av nptII (3-4 kopier). De positive prøvene kan være naturlige varianter eller kontaminering fra forskningslaboratorier. Vi konkluderer med at der er behov for utvida undersøkelser innenen for dette fagfeltet.publishedVersio