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  • 601.
    Tonnby, Emma
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Centrum för klimat och säkerhet. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Eriksson, Linn
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Centrum för klimat och säkerhet. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Ryktet går: En studie om riskkommunikation i sociala medier bland kommuners kommunikatörer i Jönköpings och Värmlands län2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I denna uppsats har vi studerat kommuners kommunikatörers syn på sociala medier som riskkommunikationsverktyg och hur de använder sociala medier som kommunikationskanal för att göra samhället bättre på att hantera risker och kriser. Det har skett en explosionsartad utveckling av sociala medier de senaste tio åren och detta har medfört att tidigare forskning om sociala medier som riskkommunikationsverktyg är utdaterad och nya möjligheter och problematiska förhållanden har identifierats. Åtta kvalitativa intervjuer med kommunikatörer från Jönköpings och Värmlands läns kommuner genomfördes och intervjuerna analyserades utifrån tematisk analys. Totalt deltog sju kommuner varav en, vid intervjutillfället, inte använde sociala medier som riskkommunikationskanal. Resultatet visar att möjligheterna med sociala medier överväger nackdelarna samt att felaktig information och desinformation upplevs av kommunikatörerna som den största utmaningen. Vissa tidigare identifierade paradoxala förhållanden med riskkommunikation kvarstår, andra ses som mindre problematiska då ytterligare fem paradoxala förhållanden har identifierats i samband med ett ökat användande av sociala medier som riskkommunikationsverktyg.

  • 602.
    Treagust, David
    et al.
    Curtin University, Perth, Australia.
    Gericke, Niklas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Learning Biology with Multiple Representations2013Konferensbidrag (Refereegranskat)
  • 603.
    Tyle, Robert
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Metoder för att etablera fri station: En jämförelsestudie av GNSS-etableringar och traditionell etablering2017Självständigt arbete på grundnivå (högskoleexamen), 5 poäng / 7,5 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syftet med detta examensarbete är att jämföra kvaliteten som erhålls vid olika typer av fri stationsetablering. Tre olika metoder har jämförts vilka är etablering mot kända stompunkter (traditionell metod), etablering mot GNSS-bestämda punkter med snabb metod och etablering mot GNSS-bestämda punkter med långsam metod. Den snabba metoden går ut på att mäta in en punkt med fem (5) positionsbestämmelser med GNSS samtidigt som totalstationen mäter in punkten som ett bakåtobjekt. Varje punkt behöver då besökas endast en gång. Den långsamma metoden går ut på att mäta in alla punkter som ska användas som bakåtobjekt med tjugo (20) positionsbestämmelser med GNSS, för att därefter mäta in dem med totalstation. Varje bakåtobjekt måste då besökas två gånger.

    Arbetet utfördes i Arvika kommun. Tre stompunkter användes som huvudsakliga bakåtobjekt. Dessa punkter användes som bakåtobjekt för att jämföra kvaliteten på GNSS-mätningarna relativt de sanna koordinaterna på stompunkterna vilka hämtas från respektive punktbeskrivning.

    Olika antal bakåtobjekt mättes in med GNSS för att undersöka hur kvaliteten förändrades i takt med att fler bakåtobjekt tillkom. Fri stationsetablering genomfördes i varje metod med tre, fem och sju bakåtobjekt. Det gjordes tre mätomgångar för att kunna jämföra mätningarna med varandra.

    Slutsatser som dras är att vid uppdatering av primärkartan räcker det med att använda den snabba GNSS-metoden tillsammans med tre bakåtobjekt för att uppnå tillfredsställande kvalitet. Vid finutsättning bör den långsamma metoden med fem bakåtobjekt användas istället. 

    Arbetet beskriver även teorin bakom GNSS-tekniken och fri station.

  • 604.
    Törnvall, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    GNSS-mätning vid olika tidpunkter: En studie om osäkerhet2017Självständigt arbete på grundnivå (högskoleexamen), 5 poäng / 7,5 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syftet med arbetet är att undersöka om olika tidpunkter under dagen påverkar osäkerheten vid GNSS-baserade mätningar. För att undersöka detta så har mätningar gjorts på två kända punkter vid flera olika tillfällen. Mätningarna som jämförts är gjorda på förmiddag, eftermiddag och kväll. Punkterna som använts ligger i Östersund och i Hallen. Utrustning som använts är en handenhet av märket Nomad och en TopCon Hiper II GNSS-mottagare med stativ och trefot. Mätningarna har gjorts med NRTK i koordinatsystemet SWEREF99 14 15. Datat analyserades i SBG GEO och jämfördes sedan i Microsoft Excel. Resultatet blev en genomsnittlig skillnad radiellt på 3 mm i plan. Vid tre av fyra tillfällen så blev osäkerheten mindre på förmiddagen än på eftermiddag/kväll. Den största skillnaden på mätningarna var 8 mm.

  • 605.
    van Deurs, M
    et al.
    Lund University; Technical University of Denmark, Denmark.
    Andersson, A
    Lund University.
    Vinterstare, J
    Lund University.
    Didenko, A
    Institute of Fisheries of the National Academy of Agrarian Sciences of Ukraine, Ukraine.
    Persson, A
    Lund University.
    Brönmark, C
    Lund University.
    Nilsson, Per Anders
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Lund University.
    Using accelerometry to quantify prey attack and handling behaviours in piscivorous pike Esox lucius2017Ingår i: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 90, nr 6, s. 2462-2469Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Accelerometer technology was used to evaluate behaviours in the teleost ambush predator pike Esox lucius foraging on crucian carp Carassius carassius. Automated rule-based estimates of prey-size determined handling time were obtained and are compared with video-recorded behaviours. Solutions to tag attachment and the limitations imposed by battery-time and data-logging capacities are evaluated.

  • 606.
    Vernby, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Effekter av höjd inkubationstemperatur på ventilationshastighet, som ett mått på metabolism, hos öring (Salmo trutta)2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The average global temperature is expected to rise by 3-5 °C at the end of the century, as a consequence of global warming. Negative effects are expected on poikilothermic animals, including fish, with changes in their physiology including metabolism. Metabolism has earlier been proven to have an association with propensities to migrate, which might be affected by raised temperatures as a consequence of global warming. The purpose of this study was to investigate if raised temperatures during incubation of eggs has an effect on metabolism in a partly migrating species of fish. The hypotheses for this study were: (i) ventilation rate (VR) will decrease as a consequence of warmer incubation temperatures, and (ii) offspring of anadromous parents are expected to have a higher VR compared to offspring of residential parents. VR, as a proxy for metabolic rate, was measured on young-of-the-year brown trout (Salmo trutta) during trials in respiration chambers. Fertilized eggs from four different crossings of parents (anadromous x anadromous, residential x residential, anadromous male x residential female, residential male x anadromous female) underwent incubation in normal and warm (normal + 3 °C) water temperatures respectively. A Two-way ANOVA showed a significant interaction between incubation temperature and crossing on VR. Warmer incubation temperatures in 3 out of 4 crossings resulted in a higher VR, except for individuals with two anadromous parents. Individuals with an anadromous father had a higher VR than individuals with a residential father. Evidence that partly supports both hypotheses was therefore found. Metabolism might have a strong genetic component, and other factors that might have an effect on metabolism and VR are epigenetics, stress, egg size etcetera. Studies of this kind will be of importance in getting a greater understanding of the effects of global warming on migrating species of fish, and on poikilothermic vertebrates in general.

  • 607.
    Vernerback, Claes
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Effect of incubation temperature on Atlantic salmon metabolism as indicated by ventilation rate2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Jordens medeltemperatur beräknas öka med upp till 5 °C det här århundradet. För fiskar, som är ektotermer, är temperatur en av de viktigaste abiotiska faktorerna och påverkar dem på en mängd olika sätt, bland annat genom förändring av fysiologiska attribut, tidpunkter för steg i livscykeln och beteende. Lax har visats växa snabbare efter att ha blivit inkuberade i varmare vattentemperatur. En möjlig förklaring till det kan vara att en förhöjd inkuberingstemperatur orsakar en lägre metabolism. Det här projektet syftade till att undersöka om så är fallet. Ägg från lax inkuberades i tre olika temperaturförhållanden: naturliga temperaturförhållanden, förhöjd temperatur och en blandad temperaturbehandling, där ägg inkuberades i förhöjd temperatur till början av januari, varefter de utsattes för naturliga temperaturförhållanden. Gälslagsfrekvens, som fungerar som en indikator för metabolism, mättes på fisk från varje behandlingsgrupp, samt fiskarnas längd och vikt. Resultaten visade signifikant lägre gälslagsfrekvenser hos fiskarna från behandlingen med förhöjd temperatur, men inte hos fiskarna från behandlingen med blandad temperatur. Detta indikerar att en förhöjd inkuberingstemperatur orsakar en lägre metabolism hos lax, och att förändringen sker senare än tidiga januari. På grund av skillnader i storlek och livsstadier hos fiskarna från de olika grupperna är resultaten dock osäkra, vilket gör att ytterligare studier behövs. En lägre ämnesomsättning påverkar fiskars beteende. En uppföljning kan därför vara att studera fiskars överlevnad i det vilda i relation till deras metabolism.

  • 608.
    Vikingsson, Amanda
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Vem kallar du för ´klimatflykting´?: En studie över hur svenska dagstidningar gestaltar klimatflyktingar2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Medeltemperaturen på jorden har höjts med 1 grad sedan förindustriell tid. Effekterna av denna temperaturhöjning visar sig i form av förhöjda havsnivåer, smältande havsis i Arktis och extrema väderförhållanden. Inom internationell politik är det numera erkänt att migration är och förblir den i särklass största effekten av klimatförändringarna. 

    Termen ’klimatflyktingar’ används som gemensam benämning för människor som tvingas fly sina hem på grund av klimatförändringar. Studien ämnar undersöka hur klimatflyktingar gestaltas i svenska dagstidningar efter klimatmötet i Paris 2015. Studien syftar vidare till att belysa vilka maktförhållanden som existerar i kontexten kring denna term. En kvalitativ innehållsanalys används för att analysera artiklar från ett antal utvalda svenska dagstidningar. Ett teoretiskt ramverk bestående av gestaltningsteori och politisk ekologi hjälper till att tolka de sju teman som analysen resulterat i. 

    Resultatet visar att klimatflyktingar avhumaniseras och förstås som en negativ effekt av klimatförändringarna. De som rymmer under termen vill dock inte associeras med den. I Sverige finns en tydlig tendens till förnekelse inför de problem som världen idag står inför till följd av den globala uppvärmningen. Samtidigt råder en stark tilltro till ekologisk modernisering. Röster inom internationell politik vill erkänna klimatflyktingar i internationell lag. Inget större agerande görs dock för att hjälpa människor som dagligen förlorar sina hem till kusterosion, förstörda jordbruksmarker eller översvämningar. 

  • 609.
    Vinterstare, Jerker
    et al.
    Lund University.
    Hegemann, Arne
    Lund University.
    Nilsson, Per Anders
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Lund University.
    Hulthen, Kaj
    Lund University.
    Bronmark, Christer
    Lund University.
    Defence versus defence: Are crucian carp trading off immune function against predator-induced morphology?2019Ingår i: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 88, nr 10, s. 1510-1521Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Numerous species adopt inducible defence strategies; that is, they have phenotypically plastic traits that decrease the risk of capture and consumption by potential predators. The benefits of expressing alternative phenotypes in high- vs. low-risk environments are well documented. However, inducible anti-predator traits are also expected to incur costs, as they are not expressed when predators are absent, yet empirical evidence of such costs remains scarce. Virtually, all animals in nature are simultaneously under strong selection to evade both capture by predators and infection by parasites or pathogens and, hence, display a diverse arsenal of defences to combat these threats, raising the possibility of trade-offs between defences. A classic example of a predator-induced morphological defence is the deep-bodied shape of crucian carp that reduces risk of predation from gape-size-limited predators. The goal of this study was to examine whether predator exposure affects also immune function in crucian carp, and whether the degree of expressed morphological defence is traded off against immune function in individuals. Following exposure to manipulations of perceived risk (predator presence/absence) in a long-term experiment (8 months), key aspects of innate immune function and individual differences in the expression of inducible morphological defence were quantified. Predator-exposed individuals showed lower haptoglobin levels and complement activity, but higher natural antibody titres than fish from predator-free conditions. When experimentally challenged with a mimicked bacterial infection (LPS injection), fish reared in the presence of a natural predator showed a weaker immune response. Moreover, among predator-exposed individuals, the magnitude of morphological defence expression correlated with both baseline immune function and the ability to mount an immune response. However, these relationships were not consistently supportive of a general trade-off among defences. Our results suggest that fish exposed to predators on average reduce investment in immune function, and, further, the observed relationships among defences in predator-exposed individuals can best be explained from individual fitness and pace-of-life perspectives.

  • 610.
    Virmaja, Tommy
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Skillnader i födoval mellan brunbjörnshonor (Ursus arctos) med och utan årsungar2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Inom födosöksteori söker och konsumerar djur föda på ett sätt som maximerar deras förmåga att reproducera sig och få sina gener representerade i kommande generationer. För att åstadkomma detta måste individer ibland anpassa sina beteenden. Brunbjörnhonor (Ursus arctos) med årsungar måste bland annat dela den föda de hittar med ungarna. För att inte riskera att ungarna dödas av hannar så har honor med årsungar under parningsperioden mindre hemområden och rör sig mindre under ett dygn än vuxna honor utan årsungar. Med bakgrund av dessa olikheter undersöks ifall honor med årsungar konsumerar annan föda jämfört med honor i andra reproduktiva kategorier. En spillningsinsamling från GPS-märkta björnar gjordes i västra Hälsingland och norra Dalarna under 2015 från 25:e maj till 11:e oktober. Inför dataanalysen delades säsongen upp i två perioder vid den 15:e juli på grund av olikheter i födotillgång samt att parningssäsongen slutar. En frekvensanalys gjordes av individernas spillningar som resulterade i en icke signifikant skillnad mellan honor med och honor utan årsungars födoval. En undersökande dataanalys av volymprocent antyder dock att det kan finnas skillnader i mängd av vissa födoämnen under parningsperioden. Dessa skillnader fanns i kategorierna ben, älghår samt övriga växtmaterial. Även om studien lider av liten provstorlek med endast fyra honor med årsungar i var och en av de båda perioderna tycks undersökningen originell med en upplösning på individnivå. Tidigare skandinaviska födovalsanalyser hos brunbjörnen har gjorts med spillning som minsta enhet.

  • 611.
    Voicu, Razvan
    et al.
    National Institute of Hydrology and Water management, Romania.
    Banaduc, Doru
    University of Sibiu, Romania.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Curtean-Banaduc, Angela
    University of Sibiu, Romania.
    Caras River Gorge aspects of salmonids' communities management- technical solutions2018Ingår i: Management of sustainable development, ISSN 2066-9380, Vol. 10, nr 2, s. 5-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There are many obstacles in rivers that prevent or hinder passage of fish past barriers. Here, we present a specially designed solution for juvenile and adult brown trout so that they may to swim past discharge-regulating weirs in the upper Caraş River in both the upstream and downstream directions. The proposed solution relies on gravity flow and will have current velocities that will not inhibit weak swimmers swimming upstream to pass the weirs. Corrosion-resistant materials and the absence of components that could potentially injure the fish will be used in the construction of these technical solutions. Although testing of the functionality of this solutions for upstream - downstream and downstream - upstream passage of weirs is needed, we believe that if implemented, it should improve connectivity especially for brown trout and consequently conserve within-stream genetic diversity in the Caraş River and where appropriate in alike other Carpathian lotic systems with similar types of weirs.

  • 612.
    Voss, Nicole
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Welk, Erik
    Martin Luther Univerity, Halle, Germany.
    Durka, Walter
    UFZ, Halle, Germany.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper. Justus-Liebig-University Giessen, Germany.
    Biological flora of Central Europe: Ceratocapnos claviculata (L.) Liden2012Ingår i: Perspectives in plant ecology, evolution and systematics, ISSN 1433-8319, E-ISSN 1618-0437, Vol. 14, nr 1, s. 61-77Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The eu-oceanic therophytic woodland herb Ceratocapnos claviculata has been expanding north- and eastwards into north temperate and subcontinental regions during the past decades. The rapid range expansion of the species may be an example of a species which is strongly profiting from global change. Against this background, in the present paper we review the taxonomy, morphology, distribution, habitat requirements, life cycle and biology of the species. (C) 2011 Elsevier GmbH. All rights reserved.

  • 613.
    Wahlberg, Sara
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Gericke, Niklas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Conceptual Demography in Upper Secondary Chemistry and Biology Textbooks' Descriptions of Protein Synthesis: A Matter of Context?2018Ingår i: CBE - Life Sciences Education, ISSN 1931-7913, E-ISSN 1931-7913, Vol. 17, nr 3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study investigates how the domain-specific language of molecular life science is mediated by the comparative contexts of chemistry and biology education. We study upper secondary chemistry and biology textbook sections on protein synthesis to reveal the conceptual demography of concepts central to the communication of this subject. The term "conceptual demography" refers to the frequency, distribution, and internal relationships between technical terms mediating a potential conceptual meaning of a phenomenon. Data were collected through a content analysis approach inspired by text summarization and text mining techniques. Chemistry textbooks were found to present protein synthesis using a mechanistic approach, whereas biology textbooks use a conceptual approach. The chemistry texts make no clear distinction between core terms and peripheral terms but use them equally frequently and give equal attention to all relationships, whereas biology textbooks focus on core terms and mention and relate them to each other more frequently than peripheral terms. Moreover, chemistry textbooks typically segment the text, focusing on a couple of technical terms at a time, whereas biology textbooks focus on overarching structures of the protein synthesis. We argue that it might be fruitful for students to learn protein synthesis from both contexts to build a meaningful understanding.

  • 614.
    Walan, Susanne
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    From doing to learning: Inquiry- and context-based science education in primary school2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The aim of this thesis is to develop an understanding of primary school teachers’ knowledge of Inquiry- and Context-Based Science Education (IC-BaSE) from different perspectives: what it is, how to use it and why these strategies are used. There are at least two reasons for performing research in this field. First, there is a need for professional development in teaching science among primary school teachers. Second, IC-BaSE has been suggested to provide useful instructional strategies for stimulating students’ interests in learning science. The thesis contains four papers with the overall research question: How do primary school teachers reflect on Inquiry- and Context-based Science Education as a framework for teaching and learning in the primary school classroom? Both quantitative and qualitative research methods have been used. The main participants in the studies were twelve primary school teachers working with 10-12 year old students. The results are discussed with reference to theories mainly based on pragmatism, but also from a sociocultural perspective. Primary school teachers found IC-BaSE to provide useful instructional strategies in the primary school classroom, as it engaged their students and developed their skills in planning inquiries. The teachers developed their knowledge about IC-BaSE, what it is and how to use it.  Furthermore, the primary purpose of using IC-BaSE seemed to be that students should have fun. Students also responded positive to the use of IC-BaSE. However when teachers were informed about their students’ responses to IC-BaSE, they became more aware of the importance of informing the students about the purposes of the activities. The findings presented show that teachers need to move forward, not only be “doing”, but also knowing why they are doing the activities and how to do them. Students’ experiences can contribute to this awareness among teachers and develop the teaching practice.

  • 615.
    Walan, Susanne
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Star Wars Irl2017Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Rymdmusik, finns det? Finns det ljud i rymden överhuvudtaget? Rymdfilmer, vad är sant och vad är falskt? Vilken roll spelar musiken i rymdfilmerna? Vi kombinerar fantastiska IRL rymdbilder med spännande musik.

  • 616.
    Walan, Susanne
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Students' responses to visits at some researchers' night events2017Ingår i: NFSUN 2017 Synopsis Book, 2017, s. 26-29Konferensbidrag (Refereegranskat)
    Abstract [en]

    Several activities around the world aim to stimulate students’ interest in science, technology, engineering and mathematics. The European Researchers' Nights are one example. In this study it was investigated how seven students in the age 15-19 years responded to a visit at Researchers' Nights events. The students were interviewed and answers were analysed based on content. The results showed that the students were all positive to the visit and in most cases it was better than they had expected. The results were organised into the main themes: expectations versus experiences, interest in research context and relevance of research. Most of the students were positive about being a scientist and could even imagine a future science career. The contexts presented at the events were catching the interest of the students and were relating to the daily life of the students, or found to be of relevance for society. The study is a pilot and will be followed by a future study with more students included.

  • 617.
    Walan, Susanne
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Teaching children science through storytelling combined with hands-on activities – a successful instructional strategy?2017Ingår i: Education 3-13, ISSN 0300-4279, E-ISSN 1475-7575, Vol. 47, nr 1, s. 34-46Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Earlier studies have discussed the usefulness of storytelling and hands-on activities when teaching young children science. However, few studies have investigated the use of the two methods in combination. This study reports on five pre-school teachers’ experience of combining storytelling and hands-on activities in teaching science and their perceived effects of the combination. Interviews with the teachers and a supplementary observation served as the data material, which was transformed into narratives and member-checked by the participating teachers. Some found the combination of methods important while others argued that hands-on activities were effective without the use of stories. The teachers’ enjoyment in adopting the combinatory method and their appreciation of the stories also made a difference.

  • 618.
    Walan, Susanne
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    The dream performance - a case study of young girls' development of interest in STEM and 21st century skills, when activities in a makerspace were combined with drama2019Ingår i: Research in Science & Technological Education, ISSN 0263-5143, E-ISSN 1470-1138, s. 1-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: There is a shortage of people in the STEM sector, and it has been argued that more needs to be done, especially to attract girls. Furthermore, there is a need to develop twenty-first-century skills. No studies seem to have explored the combination of activities in makerspaces and the use of drama to stimulate interest in STEM and development of 21st century skills.Purpose: This study focused on a project with a unique combination of makerspace activities and the use of drama. The research questions investigated the outcomes that could be identified from combining drama and activities in a makerspace, with regard to the development of interest in STEM and twenty-first-century skills.Sample: Ten girls aged 7-11 years participated. A project leader, a drama teacher and three female engineering students supported the activities.Design and methods: The project lasted 3 months. Data were collected in the form of interviews and observations with video-recordings and field-notes, as well as documentation of props made by the girls. Analyses were conducted using thematic coding and discussed through the lens of Activity Theory.Results: The results showed that some of the girls developed an interest in science and technology. The girls also developed twenty-first-century skills, in terms of creativity, problem-solving and cooperation.Conclusions: Positive outcomes were found in this project, blending drama and making in a makerspace learning environment. Future studies could investigate how other skills and knowledge in different STEM subjects can be developed in similar projects.

  • 619.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Chang Rundgren, Shu-Nu
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper.
    Investigating preschool and primary school teachers´ self-efficacy and needs in teaching science: A pilot study2014Ingår i: CEPS Journal, ISSN 1855-9719, Vol. 4, nr 1, s. 51-67Artikel i tidskrift (Refereegranskat)
  • 620.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Enochsson, Ann-Britt
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Institutionen för pedagogiska studier (from 2013).
    The potential of using a combination of storytelling and drama, when teaching young children science2019Ingår i: European Early Childhood Education Research Journal, ISSN 1350-293X, E-ISSN 1752-1807, Vol. 27, nr 6, s. 821-836Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Based on a sociocultural perspective, this study explores the outcome of using a model that combines storytelling and drama to teach young children science. The research question is: How is children’s learning affected when using a combination of storytelling and drama to explain a complex scientific concept?. Two preschools and one primary school were visited. Altogether 25 children aged 4–8 years participated. Each group listened to a story about The Rhinovirus Rita. No pictures were shown during storytelling. After the story was told, a play was performed with the children, telling the same story they just had listened to, and the children also made drawings. At a second visit to the schools, each child was interviewed individually and their drawings were used to stimulate recall. The results show that many of the children had learnt the names of immune system cells and how they work when someone has a cold. Moreover, they had also learnt that viruses cause colds. There were also a small number of children who did not show any learning development related to this specific content. Still, we argue that the combination of storytelling and drama is an instructional strategy that has positive potential when it comes to teaching children science.

  • 621.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Gericke, Niklas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Barnens universitet - Intresseskapande STEM-aktivitet?2016Konferensbidrag (Refereegranskat)
  • 622.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Gericke, Niklas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Factors from informal learning contributing to the children’s interest in STEM – experiences from the out-of-schoolactivity called Children’s University2019Ingår i: Research in Science & Technological Education, ISSN 0263-5143, E-ISSN 1470-1138, s. 1-21, artikel-id doi.org/10.1080/02635143.2019.1667321Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Previous studies have investigated effects of out-ofschoolSTEM activities aimed at stimulating children’s interest inscience with positive results. However, research has not discussedthe reasons why such activities are successful.

    Purpose: In this study, we address this gap by investigating whichfactors children themselves identified as interesting when they visitedevents at an out-of-school activity named The Children’s University.

    Sample: Children aged 8–12 participated in the study. Altogether,there were 353 children involved in the data collection.

    Design and methods: A mixed method design was used, includinga questionnaire and semi-structured interviews inwhich children’s selfreportedexperiences were collected. Likert scale questions in thequestionnairewere analysed based on descriptive statistics. The openendedquestions and data from the interviews were categorized bycontent analysis and analytically interpreted through ‘the Ecologicalframework for understanding learning across places and pursuits’.

    Results: The children were positive about their visit, and these utterancescould mainly be related to the development of the individuals’interest and knowledge according to the Ecological framework. Weidentified two new factors influencing student’s interest in STEM inout-of-school activities: appreciating the spectacular and learning;verifying two factors of importance previously suggested in the literature:appreciating the content and the learning environment.

    Conclusions: The study highlights the specific factors the childrenactually appreciated from their visits to out-of-school activities,which could be of interest for stakeholders arranging differentkinds of STEM events promoting informal learning. The contentin the activities is important as well as spectacular features. Tohave the opportunity to learn something new in an environmentthat is conducive to learning is also of importance for children.

  • 623.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Gericke, Niklas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Factors from informal learning contributing to the children's interest in STEM: experiences from the out-of-school activity called Children's University2019Ingår i: Research in Science & Technological Education, ISSN 0263-5143, E-ISSN 1470-1138, s. 1-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Previous studies have investigated effects of out-of-school STEM activities aimed at stimulating children's interest in science with positive results. However, research has not discussed the reasons why such activities are successful. Purpose: In this study, we address this gap by investigating which factors children themselves identified as interesting when they visited events at an out-of-school activity named The Children's University. Sample: Children aged 8-12 participated in the study. Altogether, there were 353 children involved in the data collection. Design and methods: A mixed method design was used, including a questionnaire and semi-structured interviews in which children's self-reported experiences were collected. Likert scale questions in the questionnaire were analysed based on descriptive statistics. The open-ended questions and data from the interviews were categorized by content analysis and analytically interpreted through 'the Ecological framework for understanding learning across places and pursuits'. Results: The children were positive about their visit, and these utterances could mainly be related to the development of the individuals' interest and knowledge according to the Ecological framework. We identified two new factors influencing student's interest in STEM in out-of-school activities: appreciating the spectacular and learning; verifying two factors of importance previously suggested in the literature: appreciating the content and the learning environment. Conclusions: The study highlights the specific factors the children actually appreciated from their visits to out-of-school activities, which could be of interest for stakeholders arranging different kinds of STEM events promoting informal learning. The content in the activities is important as well as spectacular features. To have the opportunity to learn something new in an environment that is conducive to learning is also of importance for children.

  • 624.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Jeannie, Flognman
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörsvetenskap och fysik (from 2013).
    Kilbrink, Nina
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Institutionen för pedagogiska studier (from 2013).
    Building with focus on stability and construction: Using a story as inspiration when teaching technology and design in preschool2019Ingår i: Education 3-13, ISSN 0300-4279, E-ISSN 1475-7575Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study children's learning of the concept, stability, during some building activities were investigated. It was also examined how a story can create meaning, having the children build for some animals in the story. Two preschool teachers and 10 children participated. Data consisted of video-recordings from activities with the children and was analysed through thematic coding. The findings showed that the children enjoyed to build and showed an understanding of how to build stable constructions, however without using the word stable. There were connections to the story and new stories were also made by the children during building activities.

  • 625.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Mc Ewen, Birgitta
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för hälsovetenskaper (from 2013).
    Students' reflections on participation in a science and technology school competition2018Ingår i: Electronic Proceedings of the ESERA 2017 Conference: Research, Practice and Collaboration in Science Education / [ed] Odilla Finlayson, Eilish McLoughlin, Sibel Erduran, Peter Childs, Dublin, Ireland, 2018, Vol. Part 2, s. 273-282Konferensbidrag (Refereegranskat)
    Abstract [en]

    Different kinds of efforts have been made in many countries to stimulate students' interest in science and technology, for example through school competitions. Few studies, however,have investigated the effect of school competitions in science and technology. This study centres onhow students participatingin the science and technology school competition The Technology Eightexperienced the outcomesof taking part inthe competition. Semi-structured interviews were conducted with seventeen 15-year-old students. Transcripts of the interviews were analysed based on contentand resulted in four categories: Social effects, Attitude to competitions, Stimulated interest in science and technology and Gained knowledge. The students enjoyed participating in the competition and found that it had a positive effect on the social situationin the classroom. Competitions were also appreciated and seen to encourage students to work harder. However, the competition didnot have much effect in changing interest in science and technology. Finally, the students found it difficult to express how the competition had contributed to gainingmore content knowledge in the subjects, but they emphasised the practical aspects of learning.

  • 626.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Mc Ewen, Birgitta
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för hälsovetenskaper (from 2013).
    Teachers’ and principals’ reflections on student participation in a school science and technology competition2018Ingår i: Research in Science & Technological Education, ISSN 0263-5143, E-ISSN 1470-1138, Vol. 36, nr 4, s. 391-412Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The European Union asks for renewed pedagogies in schools according to teaching strategies and necessary competences for the twenty-first century, instead of the often-used transmissive pedagogies. The national Swedish competition in science and technology for grade eight, The Technology Eight, provides an opportunity for teachers to work with instructional strategies in line with suggested pedagogies.

    Purpose: To investigate teachers’ and principals’ reflections on the competition in schools.

  • 627.
    Walan, Susanne
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Nilsson, Pernilla
    Halmstad University.
    Mc Ewen, Birgitta
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för hälsovetenskaper (from 2013).
    Why Inquiry?: Primary Teachers' Objectives in Choosing Inquiry- and Context-Based Instructional Strategies to Stimulate Students' Science Learning2017Ingår i: Research in science education, ISSN 0157-244X, E-ISSN 1573-1898, Vol. 47, nr 5, s. 1055-1074Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Studies have shown that there is a need for pedagogical content knowledge among science teachers. This study investigates two primary teachers and their objectives in choosing inquiry- and context-based instructional strategies as well as the relation between the choice of instructional strategies and the teachers' knowledge about of students' understanding and intended learning outcomes. Content representations created by the teachers and students' experiences of the enacted teaching served as foundations for the teachers' reflections during interviews. Data from the interviews were analyzed in terms of the intended, enacted, and experienced purposes of the teaching and, finally, as the relation between intended, enacted, and experienced purposes. Students' experiences of the teaching were captured through a questionnaire, which was analyzed inductively, using content analysis. The results show that the teachers' intended teaching objectives were that students would learn about water. During the enacted teaching, it seemed as if the inquiry process was in focus and this was also how many of the students experienced the objectives of the activities. There was a gap between the intended and experienced objectives. Hardly any relation was found between the teachers' choice of instructional strategies and their knowledge about students' understanding, with the exception that the teacher who also added drama wanted to support her students' understanding of the states of water.

  • 628.
    Washington, Haydn
    et al.
    Kensington Campus, Australia.
    Chapron, Guillaume
    Swedish University of Agricultural Sciences, Sweden.
    Kopnina, Helen
    International Business Management Studies, the Netherlands.
    Curry, Patrick
    The Ecological Citizen, United Kingdom.
    Gray, Joe
    University of London, United Kingdom.
    Piccolo, John
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Foregrounding ecojustice in conservation2018Ingår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 228, s. 367-374Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Justice for nature remains a confused term. In recent decades justice has predominantly been limited to humanity, with a strong focus on social justice, and its spin-off – environmental justice for people. We first examine the formal rationale for ecocentrism and ecological ethics, as this underpins attitudes towards justice for nature, and show how justice for nature has been affected by concerns about dualisms and by strong anthropocentric bias. We next consider the traditional meaning of social justice, alongside the recent move by some scholars to push justice for nature into social justice, effectively weakening any move to place ecojustice centre-stage. This, we argue, is both unethical and doomed to failure as a strategy to protect life on Earth. The dominant meaning of ‘environmental justice’ – in essence, justice for humans in regard to environmental issues – is also explored. We next discuss what ecological justice (ecojustice) is, and how academia has ignored it for many decades. The charge of ecojustice being ‘antihuman’ is refuted. We argue that distributive justice can also apply to nature, including an ethic of bio-proportionality, and also consider how to reconcile social justice and ecojustice, arguing that ecojustice must now be foregrounded to ensure effective conservation. After suggesting a ‘Framework for implementing ecojustice’ for conservation practitioners, we conclude by urging academia to foreground ecojustice. © 2018

  • 629.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper. Hokkaido University, Japan.
    Brown trout in ice-covered streams: effects of surface ice on anti-predator behavior and habitat use2018Konferensbidrag (Refereegranskat)
  • 630.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Brown trout responses to ice cover2013Konferensbidrag (Övrigt vetenskapligt)
  • 631.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Degerman, Erik
    Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agricultural Sciences, Orebro, Sweden.
    Tamario, Carl
    Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agricultural Sciences, € Orebro, Sweden.
    Calles, Olle
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Climbing the ladder: an evaluation of three different anguillid eel climbing substrata and placement of upstream passage solutions at migration barriers2019Ingår i: Animal Conservation, ISSN 1367-9430, E-ISSN 1469-1795, Vol. 22, nr 5, s. 452-462Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Conservation programmes for endangered, long-lived and migratory species often have to target multiple life stages. The bottlenecks associated with the survival of juvenile anguillid eels migrating into inland waters, the survival and growth of the freshwater life stage, as well as the recruitment and survival of silver eels, migrating back to the ocean to spawn, must be resolved. In this study, we focus on the efficiency of passage solutions for upstream migrating juveniles. Such solutions can consist of inclined ramps lined with wetted climbing substrata. We evaluated different commonly used substrata in a controlled experiment, recorded eel behaviour at the entrance of the ramp with infrared videography and validated the experimental results at a hydropower dam, where we also investigated the effects of ramp placement on performance. In the experiment on eel substratum selection, 40 % of the eels passed in lanes with studded substratum, whereas only 21 and 5 % passed using open weave and bristle substrata, respectively. Video analysis revealed that the studded substratum attracted more approaches and initiated climbs than the other substrata, but once a climb had been initiated, passage success rates did not differ between substrata. Eels using the studded substratum climbed 26 % faster than those using the bristle substratum and almost four times as fast as those climbing in the open weave. The superior performance of the studded substratum was supported by data from the field validation. Moreover, ramps positioned by the bank with low water velocities caught the most eels, but proximity to the dam had no effect on performance. To strengthen the European eel population, more juveniles need to reach their freshwater feeding grounds. A critical step to achieve this increase is to equip upstream passage solutions with suitable substrata and to optimize ramp placement at migration obstacles.

  • 632.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Overwintering behaviour of stocked brown trout: effects of the rearing environment and river habitat complexity2017Ingår i: 50th Anniversary Symposium of the Fisheries Society of the British Isles, Exeter, UK, 3-7 July, 2017, 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    In channelized and structurally simple temperature streams and rivers, adverse winter conditions may challenge the ability of riverine fishes to adapt in terms of their behaviour and physiology. Access to shelter is a key habitat factor that may influence overwinter survival chances and, consequently, population dynamics. In many river restoration projects, structural elements are added to the river to increase the complexity of the physical environment. When this habitat enhancement is combined with a stocking programme, the stocked fish mayadopt different behavioural strategies to cope with the winter season depending both onthe rearing environment in the hatchery and the level of habitat complexity in the river. In this study, young-of-the-year brown trout were reared in either barren or structurally enhanced tanks, and the effects of the rearing environment on resting ventilation rate (proxy for resting metabolic rate) and score in an open field test (proxy for activity) were assessed. In side channels of a Swedish regulatedriver, trout were then released at untreated control sites or at sites that were structurally enhanced by adding whole trees to the water. Throughout winter, trout were tracked on a weekly basis, and their movements as influenced by the river habitat complexity and the previous hatchery environment were analysed. The rearing environment affected resting metabolicrates and activity, which resulted in different behavioural overwintering strategies, and adding trees to the side channels increased apparent survival. These results have implications for managing river restoration projects and further studies of stream fish winter ecology.

  • 633.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Salmonid behaviour under winter conditions2015Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Vinterförhållanden kan spela en avgörande roll för förekomsten av fisk i våra vattendrag. Laxfiskar, som till exempel lax, öring och harr, är vinteraktiva och måste därför anpassa sin fysiologi och sitt beteende till en miljö som karakteriseras av låga och föränderliga vattenflöden, liten tillgång på föda, kallt vatten, is och mörker. Trots att dessa anpassningar är avgörande för chansen att överleva vintern, vet man relativt lite om laxfiskars vinterbeteende, speciellt i vattendrag som täcks av is. I denna avhandling presenterar jag resultat från fält- och laboratoriestudier av laxfiskars beteende under vinterförhållanden och resultaten visar att närvaron av yttäckande is ökar tillväxt och födointag, minskar stress samt påverkar var fiskar uppehåller sig och hur fiskarna interagerar med varandra. Jag har också undersökt hur laxfiskars beteende i rinnande vatten påverkas av ljusintensitet och vattentemperatur i samband med födointag. Resultaten visar att den minskade dagaktiviteten som laxfiskar uppvisar på vintern medför en kostnad i form av försämrad förmåga att fånga byten.

  • 634.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Stress responses of juvenile brown trout under winter conditions in a laboratory stream2017Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 802, nr 1, s. 131-140Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Winter can be a challenging period for fish in northern temperate rivers and streams, particularly in those that are channelized, structurally simple or regulated by, for instance, hydropower. In these systems, dynamic sub-surface ice formation commonly occurs and stable periods with ice cover may be short. Under these adverse conditions, access to shelters has been shown to be an important factor that influences overwinter survival, and exclusion from shelters by anchor ice may cause stress. Here, stress responses of juvenile brown trout under simulated winter conditions in an artificial stream were studied. Trout were subjected to three treatments in which the trout (1) were excluded from an instream wood shelter, simulating the effects of anchor ice, (2) had access to the shelter or (3) had surface ice cover in addition to the shelter. There was a positive correlation between ventilation frequency and plasma cortisol concentration. Trout without access to shelter had 30% higher ventilation frequency than trout with instream shelter and surface ice, but no differences in cortisol concentration or stress colour were found between the treatments. River regulation that reduces surface ice and increases anchor ice formation may lead to increased stress and consequently reduce overwinter survival rates.

  • 635.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Structural complexity in the hatchery rearing environment affects activity, resting metabolic rate and post‐release behaviour in brown trout Salmo trutta2019Ingår i: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 95, nr 2, s. 638-641Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effects of structural enrichment in the hatchery rearing environment of brown trout Salmo trutta was linked to post‐release performance. Enrichment resulted in reduced swimming activity scored in an open field test and reduced movement in a natural river after release. Also, enrichment increased resting metabolic rates, which correlated positively with overwinter growth.

  • 636.
    Watz, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Winter behaviour of stream salmonids: effects of temperature, light, and ice cover2013Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In boreal streams, stream salmonids typically face low water temperatures and variable ice conditions during winter, and thus stream salmonids are expected to use different behavioural strategies to cope with these environmental conditions. The studies presented in this thesis explore how temperature, light intensity, and surface ice affect salmonid behaviour, with focus on drift-feeding and ventilation rates. The first paper reports results from a laboratory study designed to measure prey capture probabilities and reaction distances of drift-feeding Atlantic salmon, brown trout, and European grayling at light intensities simulating daylight and moonlight at seven temperatures ranging from 2 to 11°C. There was a positive relationship between water temperature and prey capture probability for all three species at both light levels, but the temperature-dependence did not scale according to the Metabolic Theory of Ecology. Reaction distance was also positively related to temperature for the three species, which may explain the temperature effects on prey capture probability. The results from this study should be of interest for those working with energetic-based drift-foraging models. In the second paper, the effects of ice cover on the diel behaviour and ventilation rate of brown trout were studied in a laboratory stream. Ice cover is believed to afford protection against endothermic predators, and thus the need for vigilance should be reduced under ice cover. This hypothesis was tested by observing ventilation rates at night, dawn, and during the day in the presence and absence of real, light-permeable surface ice. Further, trout were offered drifting prey during the day to test if ice cover increased daytime foraging activity. Ice cover reduced ventilation rates at dawn and during the day, but not at night. Moreover, trout made more daytime foraging attempts in the presence of ice cover than in its absence. These results suggest that ice cover affects the behaviour of brown trout and presumably has a positive effect on winter survival. Global warming, by reducing the extent or duration of surface ice, may therefore have negative consequences for many lotic fish populations in boreal streams.

  • 637.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Bergman, Eva
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Calles, Olle
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Enefalk, Åsa
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Gustafsson, Stina
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Hagelin, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Nilsson, P. Anders
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Norrgård, Johnny
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Fortum generation.
    Nyqvist, Daniel
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Österling, Martin
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Piccolo, John J.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Schneider, Lea Dominique
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Greenberg, Larry
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Jonsson, Bror
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Norsk institutt for naturforskning, Oslo.
    Ice cover alters the behavior and stress level of brown trout Salmo trutta2015Ingår i: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 26, nr 3, s. 820-827Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Surface ice in rivers and lakes buffers the thermal environment and provides overhead cover, protecting aquatic animals from terrestrial predators. We tested if surface ice influenced the behavior (swimming activity, aggressive encounters, and number of food items eaten) and stress level (coloration of eyes and body) of stream-living brown trout Salmo trutta at temperatures of 3–4 °C in indoor experimental flumes. We hypothesized that an individual’s resting metabolic rate (RMR, as measured by resting ventilation rate) would affect winter behavior. Therefore, groups of 4 trout, consisting of individuals with high, low, or mixed (2 individuals each) RMR, were exposed to experimental conditions with or without ice cover. Ice cover reduced stress responses, as evaluated by body coloration. Also, trout in low RMR groups had a paler body color than those in both mixed and high RMR groups. Trout increased their swimming activity under ice cover, with the highest activity found in high RMR groups. Ice cover increased the number of aggressive encounters but did not influence the number of drifting food items taken by each group. In mixed RMR groups, however, single individuals were better able to monopolize food than in the other groups. As the presence of surface ice increases the activity level and reduces stress in stream-living trout, ice cover should influence their energy budgets and production. The results should be viewed in light of ongoing global warming that reduces the duration of ice cover, especially at high latitudes and altitudes.

  • 638.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Bergman, Eva
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Piccolo, John
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Effects of ice cover on the diel behaviour and ventilation rate of juvenile brown trout2013Ingår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 58, nr 11, s. 2325-2332Artikel i tidskrift (Refereegranskat)
    Abstract [en]
    1. Winter ice conditions in boreal streams are highly variable, and behavioural responses by fish to river ice may affect overwinter survival rates. One type of ice, surface ice, stabilises water temperatures, reduces instream light levels and may provide overhead cover.
    2. Because surface ice is believed to afford protection against endothermic predators, we predicted that metabolic costs associated with vigilance would be lower under surface ice than in areas lacking surface ice. This potentially favourable effect of ice cover was tested by observing ventilation rates of juvenile brown trout (Salmo trutta) in a laboratory stream at dawn, during the day and at night in the presence and absence of real, light-permeable surface ice. Further, we offered trout drifting prey during daylight to test whether ice cover increased daytime foraging activity.
    3. Ice cover reduced ventilation rates during the day, but not at night or dawn. Moreover, fish made more daytime foraging attempts in the presence of ice cover than in its absence.
    4. We suggest that the most plausible explanation for these results is that fish experience a reduced perceived predation risk under surface ice.
  • 639.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Bergman, Eva
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Piccolo, John
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Ice cover affects the growth of a stream-dwelling fish2016Ingår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 181, nr 1, s. 299-311Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Protection provided by shelter is important for survival and affects the time and energy budgets of animals. It has been suggested that in fresh waters at high latitudes and altitudes, surface ice during winter functions as overhead cover for fish, reducing the predation risk from terrestrial piscivores. We simulated ice cover by suspending plastic sheeting over five 30-m-long stream sections in a boreal forest stream and examined its effects on the growth and habitat use of brown trout (Salmo trutta) during winter. Trout that spent the winter under the artificial ice cover grew more than those in the control (uncovered) sections. Moreover, tracking of trout tagged with passive integrated transponders showed that in the absence of the artificial ice cover, habitat use during the day was restricted to the stream edges, often under undercut banks, whereas under the simulated ice cover condition, trout used the entire width of the stream. These results indicate that the presence of surface ice cover may improve the energetic status and broaden habitat use of stream fish during winter. It is therefore likely that reductions in the duration and extent of ice cover due to climate change will alter time and energy budgets, with potentially negative effects on fish production.

  • 640.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Bergman, Eva
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Piccolo, John
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Prey capture rates of two species of salmonids (Salmo trutta and Thymallus thymallus) in an artificial stream: effects of temperature on their functional response2014Ingår i: Marine and Freshwater Behaviour & Physiology, ISSN 1023-6244, E-ISSN 1029-0362, Vol. 47, nr 2, s. 93-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The foraging success of predators depends on how their consumption of prey is affected by prey density under different environmental settings. Here, we measured prey capture rates of drift-feeding juvenile brown trout and European grayling at different prey densities in an artificial stream channel at 5 and 11 °C. Capture rates were lower at 5 than at 11 °C, and the difference was most pronounced at high prey densities. At high prey densities, we also observed that European grayling had higher capture rates than brown trout. Type III functional response curves, i.e. sigmoidal relationships between capture rates and prey densities, fitted the data better than type I (linear) and II (hyperbolic) curves for all four combinations of temperatures and species. These results may explain the dominance of grayling in stream habitats with low water velocities and results such as these may be of use when developing foraging-based food web models of lotic ecosystems that include drift-feeding salmonids.

  • 641.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Bergman, Eva
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Piccolo, John J.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Winter Behavior of Brown Trout: The Presence of Ice Cover Influences Activity, Stress and Growth2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    Predation on fish by mammals and birds may be high during winter in boreal streams, and juvenile salmonids respond by reducing their daytime activity to minimize exposure. Surface ice may offer protection from terrestrial predators, and salmonids under ice cover should spend less time on anti-predator behaviors and increase their activity. Using brown trout as a test species, these predictions were tested in laboratory and field experiments.

    In an artificial laboratory stream, the presence of ice cover reduced stress and increased swimming activity, foraging and aggression. The effect of ice cover on activity was greatest for trout with high resting metabolic rates, suggesting that individual intraspecific differences in metabolism may influence the strategies used to cope with different winter conditions. In a boreal forest stream, we simulated ice by suspending plastic sheeting over five 30-m-long stretches, and trout that spent winter under this simulated ice cover grew better than trout in control stretches. These results may explain why salmonid production is high in rivers with long periods of stable ice cover and should be viewed in light of ongoing global warming.

  • 642.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan.
    Calles, Olle
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Carlsson, Niclas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Teemu, Collin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Huusko, Ari
    Natural Resources Institute Finland (Luke), Kainuu Fisheries Research Station, Paltamo, Finland.
    Jörgen, Johnsson
    Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
    Nilsson, Per Anders
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Lund University.
    Norrgård, Johnny
    Gammelkroppa Lax, Filipstad.
    Nyqvist, Daniel
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Institute of Marine Research in Norway, Bergen, Norway.
    Wood addition in the hatchery and river environments affectspost-releaseperformance of overwintering brown trout2018Ingår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 64, nr 1, s. 71-80Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Habitat structural complexity affects the behaviour and physiology of individuals,and responses to the environment can be immediate or influence performancelater in life through delayed effects.

    2. Here, we investigated how structural enrichment, both pre-release in the hatcheryrearing environment and post-release in the wild, influenced winter growthand site fidelity of brown trout stocked into side channels of a regulated river.

    3. Experiencing structural enrichment in the rearing environment during 3 months inautumn had no pre-release effect on growth, but a delayed positive effect afterrelease during the subsequent winter. Moreover, trout recaptured in wood-treatedsections of the side channels had grown more than trout recaptured in controlsections. Wood enrichment in the side channels also increased overwinter sitefidelity.

    4. These results show that adding structure during a relatively short period may altergrowth trajectories, and adding wood to side channels is a cost-effective methodto enhance winter habitat carrying capacity for juvenile salmonids in regulatedrivers.

  • 643.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Elghagen, Jonas
    Elghagen Fiskevård.
    Nilsson, Per Anders
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Department of Biology - Aquatic Ecology, Lund University.
    Calles, Olle
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Evaluation of a novel mobile floating trap for collecting migrating juvenile eels, Anguilla anguilla, in rivers2017Ingår i: Fisheries Management and Ecology, ISSN 0969-997X, E-ISSN 1365-2400, Vol. 24, nr 6, s. 512-514Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To improve the situation for the threatened European eel in regulated rivers, better methods need to be developed that more efficiently collect and transport juvenile eels past dams. In this study, a novel mobile, floating eel trap is described, and the results from an evaluation of the trap in two Swedish regulated rivers are presented. The mobile trap was designed to reduce the length of the climbing distance while maximizing the width of the entrance. The mobile trap caught more juvenile eels than a stationary eel ladder, serving as control. Furthermore, the mobility of the floating trap enables adaptive placement and thus offers managers the possibility to search for the spatial optimum for trapping efficiency.

  • 644.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Nilsson, Per Anders
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Lund University.
    Degerman, Erik
    Swedish University of Agricultural Sciences.
    Tamario, Carl
    Swedish University of Agricultural Sciences.
    Calles, Olle
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Enhancing upstream passage solutions for juvenile eels: Effects of climbing substrate and ramp placement2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Juvenile anguillid eels migrating into inland waters often face migration barriers. Upstream passage solutions normally consist of inclined ramps lined with a wetted climbing substrate. In this study, we compared the performance of three commonly used substrate types in a controlled experiment, using European eel as the test species. We also analyzed climbing behavior with videography and validated the experimental results under natural conditions at a hydropower plant. In addition, we investigated the effects of ramp placement. Studded substrate attracted more approaches and climbs and passed more eels at a higher climbing velocity than open weave and bristle substrates, results that were confirmed by the field validation. Moreover, ramps placed in the tailrace caught more eels in low than in high water velocities. To conserve anguillid eels, both safe routes for downstream-migrating adult silver eels and improved recruitment at the freshwater feeding life stage must be achieved. Optimizing ramp position and equipping upstream passage solutions with functioning climbing substrate are key factors to enhance the performance of eel ramps.

  • 645.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan.
    Otsuki, Y.
    Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
    Nagatsuka, K.
    Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
    Hasegawa, K.
    Hokkaido National Fisheries Research Institute, Japan Fisheries Research and Education Agency, Sapporo, Japan.
    Koizumi, I.
    Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan.
    Temperature-dependent competition between juvenile salmonids in small streams2019Ingår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, s. 1534-1541Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biotic interactions affect species distributions, and environmental factors that influence these interactions can play a key role when range shifts in response to environmental change are modelled. In a field experiment using enclosures, we studied the effects of the thermal habitat on intra- versus inter-specific competition of juvenile Dolly Varden Salvelinus malma and white-spotted charr Salvelinus leucomaenis, as measured by differences in specific growth rates during summer in allopatric and sympatric treatments. Previous laboratory experiments have shown mixed results regarding the importance of temperature-dependent competitive abilities as a main driver for spatial segregation in stream fishes, and no study so far has confirmed its existence in natural streams. Under natural conditions in areas where the two species occur in sympatry, Dolly Varden dominate spring-fed tributaries (cold, stable thermal regime), whereas both species often coexist in non-spring-fed tributaries (warm, unstable thermal regime). Enclosures (charr density = 6 per m2) were placed in non-spring-fed (10–14°C) and spring-fed (7–8°C) tributaries. In enclosures placed in non-spring-fed tributaries, Dolly Varden grew 0.81% per day in allopatry and had negative growth (−0.33% per day) in sympatry, whereas growth rates were similar in allopatry and sympatry in spring-fed tributaries (0.68 and 0.58% per day). White-spotted charr grew better in sympatry than in allopatry in both thermal habitats. In non-spring-fed tributaries, they grew 0.17 and 0.79% per day and in spring-fed tributaries 0.46 and 0.75% per day in allopatry and sympatry, respectively. The negative effect of inter-specific competition from white-spotted charr on Dolly Varden thus depended on the thermal habitat. However, there was no strong evidence of a temperature-dependent effect of intra- and inter-specific competition on white-spotted charr growth. Multiple factors may shape species distribution patterns, and we show that temperature may mediate competitive outcomes and thus coexistence in stream fish. These effects of temperature will be important to incorporate into mechanistic and dynamic species distribution models.

  • 646.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Piccolo, John J.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Greenberg, Larry
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Bergman, Eva
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Avdelningen för biologi.
    Temperature-dependent prey capture efficiency and foraging modes of brown trout Salmo trutta2012Ingår i: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 81, nr 1, s. 345-350Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Prey capture success and foraging mode were studied in brown trout Salmo trutta at temperatures ranging from 5·7 to 14·0° C. At low temperatures, there was a positive correlation between prey capture success and the proportion of time that the fish spent holding feeding stations. This correlation was not found at temperatures >10° C.

  • 647.
    Wengström, Niklas
    et al.
    Göteborgs universitet. Swedish Anglers Assoc, Gothenburg, Sweden.
    Wahlqvist, Fredrik
    Göteborgs universitet.
    Näslund, Joacim
    Göteborgs universitet.
    Aldvén, David
    Göteborgs universitet.
    Závorka, Libor
    Göteborgs universitet. Univ Toulouse 3, CNRS, UMR EDB Toulouse 5174, Midi Pyrenees, France..
    Österling, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Höjesjö, Johan
    Göteborgs universitet.
    Do individual activity patterns of brown trout (Salmo trutta) alter the exposure to parasitic freshwater pearl mussel (Margaritifera margaritifera) larvae?2016Ingår i: Ethology, ISSN 0179-1613, E-ISSN 1439-0310, Vol. 122, nr 9, s. 769-778Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The hypothesis that inter-individual differences in the activity of brown trout alter the exposure to parasitic freshwater pearl mussel glochidia was tested in a Swedish stream. Wild yearling brown trout (N=103) were caught, individually tagged for identification, and scored for open-field activity during standardized laboratory tests in June. Fifty gravid freshwater pearl mussels were relocated to the stream, where after the trout were released back into the stream. The fish were recaptured in October (N=35), checked for glochidia encystment (infested individuals: n=6), and re-scored for open-field activity traits. Swimming velocity during the test was higher in fish infected with glochidia, suggesting that high activity could increase their exposure to glochidia. Potentially, as metabolism and ventilation rate typically increase with activity, elevated activity may lead to an increased likelihood of glochidia passing over the gills. This novel finding suggests that glochidia infestation is non-random and that the behavior of the host fish can influence the likelihood of glochidia infestation.

  • 648.
    Wik, Malin
    et al.
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Handelshögskolan (from 2013).
    Nyberg, Lars
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Centrum för klimat och säkerhet (from 2013). Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Karlstad Univ, Ctr Climate & Safety, SE-65188 Karlstad, Sweden.;Karlstad Univ, CNDS, SE-65188 Karlstad, Sweden..
    Magnusson, Monika
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Handelshögskolan (from 2013). Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Behov av datorbaserade metoder och verktyg för krisövning: Intervjustudie i Inre Skandinavien2017Rapport (Refereegranskat)
    Abstract [sv]

    Inom ramen för projektet CriseIT (www.criseit.org) har en intervjustudie genomförts med norska och svenska krisberedskapsaktörer. 19 respondenter från totalt 16 aktörer intervjuades om deras syn på behovet av krisövning, vad som fungerar bra och dåligt med de övningsmetoder som vanligtvis används, och vilken nytta de kunde se med datorbaserade övningsverktyg. Svaren visar på ett stort behov av att öva mer, gärna i form av mindre och kortare övningar. Det finns en rörelse bort från scenariobaserade övningar till övningar där olika förmågor står i centrum. Flertalet aktörer anser att de planerar och genomför övningar med gott resultat men att det saknas en systematik i hur utvärderingar leds vidare i ett förbättringsarbete. Det finns intresse men också tveksamhet inför att involvera allmänheten i krisövning, men ett sätt att hantera bland annat säkerhetsaspekter vore att gå via frivilligorganisationer som kan bistå med organisering och viss utbildning.

    Respondenterna visar stort intresse för datorbaserade övningsverktyg som ett medel för att öka krismedvetenheten och kunskapen som stödjer den egna rollen. De kan också se potentiella problem, t ex att vissa personer har svårt att ta till sig ny teknik och att det kan finnas risk att resurser till andra övningsformer minskas. Bland de fördelar som nämndes var möjlighet att öva oftare, med fler aktörer, och att öva på olika platser vid olika tidpunkter. Man ser också förbättrade möjligheter att öva utdragna kriser. Den målgrupp som lyfts fram som särskild intressant fördatorbaserade övningsverktyg är krisledningsorganisationen, dvs. den strategiskan ivån. Flera nämner också behovet av bättre planeringsstöd för säkerhets-/beredskapssamordnarna.

    En slutsats vi dragit är att det är viktigt att digitala krisövningsverktyg är webbaserade och bygger på standarder. Detta för att möjliggöra att verktygen kan användas distribuerat, i samarbete mellan olika organisationer och inte kräver lokala installationer i de olika hårt styrda IT-miljöerna. Det bör också vara verktyg som fungerar på såväl smartphone som surfplatta och PC. I stort bör de system som används under verkliga kriser användas även under övning.

  • 649.
    Winser, Helena
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Host - parasite interactions:: the relationship between encystment load of the freshwater pearl mussel (Margaritifera margaritifera) and genetic diversity of its host (Salmo trutta)2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The freshwater pearl mussel (FPM, Margaritifera margaritifera) is an endangered bivalve mollusc with an obligatory larval parasitic phase on brown trout (Salmo trutta). The FPM has declined throughout its entire range due to causes such as habitat degradation, eutrophication, acidification, changed hydrology and lack of host fish. This study aimed to investigate if heterozygosity, allelic richness, number of alleles, inbreeding and differentiation of brown trout (Salmo trutta) are related to the encystment load of glochidia larvae of the FPM. The results showed that the observed heterozygosity was negatively related to encystment load. This may be a result of the fact that high heterozygosity is generally associated with a strong immune system that wards off parasities. High heterozygosity may also be an advantage for the host, because it results in a larger potential for selection against the parasite in the host-parasite arms race. There was also a positive relationship between the inbreeding coefficient and glochidia encystment. This makes sense since high inbreeding is negatively related to heterozygosity. High inbreeding of trout should thus reduce the ability of inbred trout populations to ward off parasites. The results may have implications for conservation management. Introductions of foreign trout strains that alter the genetic interactions between the host fish and the parasitic mussel should be managed. Small and fragmented trout mussel populations, with typically high inbreeding coefficients, may have a relatively high probability to reproduce and survive and it may therefore be worthwhile to protect these trout populations. However, inbred trout populations should be managed with care, since inbreeding increases the risk of extinction of the trout. If a trout population is extinct, their sympatric mussel population may thus face extinction as well. 

  • 650.
    Zetterlund, Sofie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Potential för återintroduktion av lax (Salmo salar L.) i Bollnäsströmmarna: en sårbarhetsanalys2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Förvaltning av lax är en komplicerad uppgift som kräver stor förståelse för både laxen och de antropogena effekter som påverkar den. Vattenkraftverk har stor påverkan på laxen genom oregelbundna flöden, reducerad vattenföring och barriärer i vandringsvägar. Laxen är beroende av att vandra för att optimera tillväxt, överlevnad och reproduktion. Östersjöns laxbestånd minskade kraftigt mellan 1950- och 1980-talet till följd av dammutbyggnad och överfiske. Redan i början av 1900-talet började det lokala laxbeståndet i älven Ljusnan att sjunka av samma orsaker. Idag finns ingen lax kvar i Ljusnan. För att möjliggöra en återintroduktion av lax krävs möjlighet för vandring och tillgång på reproduktionshabitat. Bollnäsströmmarna bedöms med sina 6,6 km historiskt ha stått för 25 % av hela Ljusnans laxproduktion. Syftet med denna studie var att simulera en återintroduktion av lax i Bollnäsströmmarna och att genom sårbarhetsanalys undersöka om utplantering av romkorn kan resultera i en överlevande laxpopulation. Simuleringarna utfördes med dagens förutsättningar med undantag av att de passagefria kraftverken ersattes med passagelösningar av bästa möjliga teknik. Utöver detta undersöktes effekter av ökad passagedödlighet förbi kraftverken, habitatåterställande åtgärder och utökade supplementära utsättningar av romkorn. Sammanlagt nio sårbarhetsanalyser utfördes i simuleringsprogrammet Vortex. Resultatet av studien visar att utplantering av romkorn kan producera en laxpopulation som överlever under en hundraårsperiod. Efter en initial populationsökning under tio år sjunker dock tillväxten konstant resterande nittio år vilket med största sannolikhet hade resulterat i en utdöd population över en större tidsrymd. Den potentiella laxpopulationen var mycket känslig för ökad passagedödlighet med en hög utdöenderisk efter endast en liten ökning. Både habitatåterställande åtgärder och supplementära utsättningar av rom gav positiva effekter på populationsstorleken men inget scenario lyckades producera ett stabilt och livskraftigt bestånd vilket tyder på att fler åtgärder krävs för ett lyckat återintroduktionsprojekt.  

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