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Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 501.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, B.
    Åldersstrukturer och begränsande faktorer för rekrytering2005Konferansepaper (Fagfellevurdert)
  • 502.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, B.
    Åldersstrukturer och begränsande faktorer för rekrytering hos flodpärlmusslan2006Inngår i: Flodpärlmussla vad behöver vi göra föra att rädda arten?, Karlstad: Karlstad University Studies , 2006, Vol. 2006, 1:15Kapittel i bok, del av antologi (Fagfellevurdert)
  • 503.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, B
    Greenberg, L
    Impact of turbidity and sedimentation on recruitment, growth and host fish of M. margaritfera2009Konferansepaper (Fagfellevurdert)
  • 504.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, Björn
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Anthropogenic impact on recruitment, growth and host-fish of Margaritifera margaritifera.2011Konferansepaper (Fagfellevurdert)
  • 505.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, Björn
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Impact of habitat degradation on recruitment of the freshwater pearl mussel M. margaritifera.2010Konferansepaper (Fagfellevurdert)
  • 506.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, B.L.
    Hultman, J.
    Population structure of Margaritifera margaritifera in streams with and without recent recruitment2003Konferansepaper (Fagfellevurdert)
  • 507.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Bergman, E.
    Greenberg, L.
    Baldwin, B.S.
    Mills, E.L.
    Indirect environmental interactions between filter feeding mussels and bioturbating mayflies2004Konferansepaper (Fagfellevurdert)
  • 508.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Bergman, Eva
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Baldwin, Brad S.
    St Lawrence University, Canton, NY, USA.
    Mills, Edward L.
    Cornell Biological Field Station, Bridgeport, NY, USA.
    Turbidity-mediated interactions between invasive filter-feeding mussels and native bioturbating mayflies2007Inngår i: Freshwater BiologyArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. Invasive dreissenid mussels are known to cause large ecosystem changes because of their high filter-feeding capacity, while native bioturbators may interfere with the mussels filter feeding. In this experiment, we investigated indirect environmental interactions between invasive filter-feeding dreissenid mussels (zebra and quagga mussels) and native recolonizing bioturbating hexagenid mayflies (Hexagenia) at two mussel densities and two Hexagenia densities in a 2-month long laboratory experiment.2. Mean turbidity increased with increasing density of Hexagenia and decreased with increasing density of mussels. Turbidity showed the fastest decline at the highest mussel density, and no decline or a lower rate of decline at the low mussel density, dependent on Hexagenia density.3. Mussel growth decreased with increasing Hexagenia density at low but not at high mussel density. Moreover, growth of mussels decreased as a function of increased mean turbidity at low mussel density but not at high mussel density. Filtering activity at thehighest mussel density increased after introduction of food at the lower two densities of Hexagenia, but was constantly high at the highest Hexagenia density.4. There was no difference in emergence of Hexagenia among the treatments, but mortality of Hexagenia was higher in the presence of mussels than in their absence.5. Our results indicate that interactions between dreissenids and hexagenids are mediated through the sediment, and depend on density of both dreissenids and hexagenids. As the natural densities of these animals vary considerably within lakes, their growth and survival because of indirect environmental interactions is expected to vary spatially

  • 509.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Calles, Olle
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Gustafsson, Stina
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Technical fishways, nature-like fishways or biocanals?2011Konferansepaper (Annet vitenskapelig)
  • 510.
    Österling, Martin E
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, Björn L
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Greenberg, Larry A
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Habitat degradation and the decline of the threatened mussel Margaritifera maragaritifera: influence of turbidity and sedimentation on mussel an its host2010Inngår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 47, nr 4, s. 759-768Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. Habitat degradation is a major reason for species extinctions. For parasite–host interactions, the decline of a parasite may not only be related to the parasite’s tolerance to habitat degradation but also indirectly through the host’s tolerance to the same disturbance.

    2. Our objective was to explore the cause of population declines of the freshwater pearl mussel Margaritifera margaritifera by relating the age distribution, density and growth of the mussels with turbidity, sedimentation rates and density of the mussel’s host, trout Salmo trutta, in 26 Swedish streams.

    3. An analysis of the age structure of nine mussel populations showed that maximum age differed by 60 years, with five populations having low proportions of juvenile mussels. Adult mussel density was higher at sites where juvenile mussels occurred than at sites lacking juvenile mussels.

    4. Growth of adult mussels during the past 10 years was lower in the five streams lacking recent recruitment than in the four streams with recent recruitment, indicating that some environmental factor may be negatively impacting these populations.

    5. A comparison among 24 populations indicated that turbidity and sedimentation may be responsible for recruitment failure in 58% of the populations. The age of the youngest mussel was positively related to turbidity and sedimentation, and juvenile mussel density was negatively related to turbidity and sedimentation. In contrast, trout density was not related to recruitment of mussels or sedimentation, but was positively related to turbidity in all streams, both with and without recent mussel recruitment.

    6.Synthesis and applications. Recruitment failure of M. margaritifera appears to be related to its own vulnerability to turbidity and sedimentation rather than to its host’s response to this type of habitat degradation. The results from our study suggest that managers might be able to evaluate the potential viability of mussel populations by measuring stream turbidity. Restoration activities to improve the mussels’ environment should focus on reducing fine material transport into streams.

  • 511.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Arvidsson, Björn L
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Relationship of biotic and abiotic factors to recruitment patterns in Margaritifera margaritifera2008Inngår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 141, nr 5, s. 1365-1370Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated relationships of biotic and abiotic factors to recruitment patterns of the endangered freshwater pearl mussel (Margaritifera margaritifera) in 10 Swedish streams. We found that the maximum proportion of gravid mussels did not differ between streams with and without recent recruitment. Moreover, the mean glochidial load on trout (Salmo trutta), which was positively related to adult mussel density, did not differ significantly between these stream types. Thus, the larval stages of the freshwater pearl mussel were not related to recruitment failure. Instead, recruitment is probably hindered at the next stage in the life history of the mussels, the benthic stage, and may be related to sedimentation as turbidity was four times greater in streams lacking recent recruitment than in streams with recent recruitment. Furthermore, we found that juvenile mussel density was positively related to the number of glochidial infections per stream area in streams with ongoing recruitment, indicating that successful recruitment in these streams may depend on both mussel and trout density. Future research should thus examine biotic interactions between mussels and trout as well as the effects of sedimentation on benthic-living mussels.

  • 512.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Gustafsson, Stina
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Calles, Olle
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Technical fishways, nature-like fishways or biocanals?2011Konferansepaper (Fagfellevurdert)
  • 513.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Högberg, Jan-Olov
    The impact of land use on the mussel Margaritifera margaritifera and its host fish Salmo trutta.2012Konferansepaper (Fagfellevurdert)
  • 514.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Mejdell Larsen, Björn
    Norwegian Institute for Nature Research (NINA), Trondheim, Norway.
    Impact of origin and condition of host fish (Salmo trutta) on parasitic larvae of Margaritifera margaritifera2013Inngår i: Aquatic conservation, ISSN 1052-7613, E-ISSN 1099-0755, Vol. 23, nr 4, s. 564-570Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Encystment abundance differed between the brown trout strains shortly after encapsulation. Encystment abundance then decreased at different rates and resulted in a changed relationship in encystment abundance between the brown trout strains when the experiment was terminated. One of the allopatric brown trout strains had higher encystment abundance than the other brown trout strains.

    The larvae grew at different rates, and the allopatric brown trout strain with the highest encystment abundance had the largest larvae at the end of the experiment. There was a significant positive relationship between the mean condition factor and shell length of the brown trout strains.

    The experiment showed that the potential numbers of juvenile mussels may be restricted at the parasitic life-stage on sympatric brown trout strains. Innate differences in energy resources and immune defence between brown trout strains may be important for parasitic growth, because the condition factor of brown trout strains may be positively related to energy resources for the larvae, and negatively related to host fish immune defence.

    The present experiment showed that it may be important to investigate and manage unionid mussels' parasitic larval stage on host fish. Infestation experiments, like the one presented here, may inform managers if the parasitic stage is functioning properly. They can also evaluate host fish strains used for introductions in streams where natural fish strains have disappeared, but mussels persist. Such experiments have applications in breeding programmes for mussels, as this is an increasing management measure in threatened mussel populations.

  • 515.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Söderberg, Håkan
    Anthropogenic changes of brown trout Salmo trutta and the impact on its parasitic mussel Margaritifera margaritifera.2012Konferansepaper (Fagfellevurdert)
  • 516.
    Österling, Martin
    et al.
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Wengstrom, Niklas
    Univ Gothenburg, Dept Biol & Environm Sci, SE-40530 Gothenburg, Sweden..
    Test of the host fish species of a unionoid mussel: A comparison between natural and artificial encystment2015Inngår i: Limnologica, ISSN 0075-9511, E-ISSN 1873-5851, Vol. 50, s. 80-83Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many of the unionoid mussel species are threatened, and to be able to develop strategies for effective conservation, one of the needs is to distinguish host fish species from non-host fish species using reliable methods. Margaritifera margaritifera lives as a parasite on brown trout (Salmo trutta) and/or Atlantic salmon (Salmo solar). The aim was to compare the reliability of two methods measuring the host specificity of M. margaritifera in two rivers that flow out into Skagerrak in the Atlantic Ocean. A second aim was to compare the time- and cost-efficiency of the two methods. The methods were (1) natural encystment abundances on fish in their native streams using electrofishing, and (2) encystment abundances from controlled artificial infestation in aquaria, on fish that were sacrificed. In both rivers, young-of-the-year (YOY), but not older brown trout, were naturally infested with relatively low loads of glochidia larvae, while the Atlantic salmon was not infested at all. When using artificial infestation, both YOY and older brown had encysted glochidia larvae on their gills, while glochidia larvae were not able to develop in Atlantic salmon at all. Here, the encystment was higher on the brown trout from the Lade River, and older brown trout from the Lade River did not seem to have as strong immunity response compared to older brown trout from the Brattefors River. In summary, brown trout is the only host fish for M. margaritifera in these rivers. Both methods can be used to discriminate between host fish species, but the method measuring natural encystment seems most time- and cost-efficient. In addition, natural encystment can be measured using a non-destructive photo-method, and is therefore suggested to be used when discriminating between host fish species for M. margaritifera. (C) 2014 Elsevier GmbH. All rights reserved.

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