Naturresurs rinnande vatten

1

AUG 2017

Senior lecturer position: Landscape ecology

Posted by Daniel Nyqvist | Karlstads universitet

River Klarälven, Värmland, Sweden.

A position as ”Senior lecturer in biology with specialisation in landscape ecology” is open for applicants at Karlstad University. The position is full time and permanent employment. It ”…involves teaching ecology at the undergraduate level, teaching specialisation courses in conservation biology, evolutionary biology or behavioural ecology, as well as relevant courses at the Master level – primarily in conservation biology. The successful applicant may also be required to teach courses in the teacher education programme or other courses in the biology programme. The position also involves complementing the research already conducted in the biology group, as well as supervising future doctoral students. We expect the successful applicant to develop new externally funded research projects together with researchers in the River Ecology and Management research group. Cooperation with the education research group SMEER is also possible…”

Last day of application is 2017-09-30. Read more about the position, and apply, on kau.se.

21

JUN 2017

Graduate student position in stream fish ecology and habitat use

Posted by Daniel Nyqvist | Nyheter

A graduate student position (licentiate) in the field stream fish ecology and habitat use, is now open for applicants at Karlstad University. The position is a full time position for 2 years within the River Ecology and Management (NRRV) group at the Department of Environmental and Life Sciences. Read more about the position on kau.se.

15

JUN 2017

Paper: Evaluating temperature- and host-dependent reproduction ina freshwater mussel

Posted by Daniel Nyqvist | Projekt Målarmusslan

Adult thick shelled river mussel (Unio crassus) from the River Tommarpsån, Sweden.

Lea Schneider, Anders Nilsson, and Martin Österling from Karlstad University, recently published the scientific article ”Evaluating temperature- and host-dependent reproduction in the parasitic freshwater mussel Unio crassus” in the journal Hydrobiologia. In the article they present a study on the thick shelled river mussel (Unio crassus) and its release of glochidia (mussel larvae) in different temperature regimes.

In the abstract they write: ”Adaptation to temperature regimes and host presence may enhance fitness in parasites. In an experimental study, we evaluated the timing of glochidia release by Unio crassus subjected to three spring water temperature regimes in the presence and absence of the host fish Cottus gobio. The timing of glochidia release was delayed at (i) constantly low temperatures (<10°C), in contrast to earlier and pronounced releases at (ii) natural temperature increases that level off at intermediate temperatures (10–15°C), and (iii) higher-than-normal temperatures (10–20°C). Mussels from treatment (i) that had not released glochidia during the experiment did so soon after being moved to the temperature in (ii), indicating a temperature threshold for glochidia release. Neither host fish presence nor the combined effect of temperature and host fish presence significantly affected the timing of glochidia release. The treatment with natural spring water temperatures indicated possible fitness benefits for U. crassus through combined effects of high intensities of glochidia releases and high survival of released glochidia. The furthered understanding of climate change effects on mussel and host phenology in seasonal environments, potentially inducing temporal mismatches of glochidia release to host availability, is key to mussel conservation.”

Acces the paper here: Evaluating temperature- and host-dependent reproduction in the parasitic freshwater mussel Unio crassus

The research was part of the LIFE project UCforLIFE. Read more about the thick shelled river mussel and related conservation work at the projects homepage: www.ucforlife.se

14

JUN 2017

Welcome to NRRV: Karl Filipsson

Posted by Daniel Nyqvist | Vinterekologi

Karl Filipsson, PhD-student at Karlstad University.

Karl Filipsson has recently joined the NRRV-research group. Here he writes about his previous work and what he intends to do as a PhD-student at Karlstad University:

My name is Karl Filipsson and I recently started my PhD in the River Ecology and Management Research Group (NRRV) at Karlstad University, where I am going to study the winter ecology of stream fishes in relation to climate change. I have a master’s degree in biology from the University of Gothenburg, with focus on aquatic and evolutionary ecology. Although I have a broad interest in fish ecology and behavior, I have developed a special interest for fish inhabiting streams. In my master project I studied the effect of parasitic freshwater pearl mussel (Margaritifera margaritifera) larvae on brown trout (Salmo trutta). The project mainly examined behavioral responses in the host fish, but growth and cardiorespiratory parameters were measured as well.

In my PhD I will use an experimental approach to look at the consequences of warmer winters on predator-prey interactions and early life-history performance in stream fishes. I will use brown trout and burbot (Lota lota) as model species. River ecosystems and associated fish populations have a significant role in providing important ecosystem services. Therefore, it is of great importance to acquire knowledge on the winter ecology of stream fishes under climate change. Hopefully, results from this project will not only elucidate how stream fishes are adapted to winter conditions and respond to environmental change, but will also provide information for stakeholders and decision makers on how to manage fish populations and stream ecosystems in a future influenced by global climate change.

In addition to research, I have a great interest in scientific outreach. I have previously been working at the science center Universeum in Gothenburg and as scuba diving guide, and I am very keen on taking on the challenge to communicate research to the broader public and to be teaching in higher education.”

Some of Karls previous work on the interaction between juvenile brown trout and frehswater pearl mussel larvae is published in the scientific articles Encystment of parasitic freshwater pearl mussel (Margaritifera margaritifera) larvae coincides with increased metabolic rate and haematocrit in juvenile brown trout (Salmo trutta) and Heavy loads of parasitic freshwater pearl mussel (Margaritifera margaritifera L.) larvae impair foraging, activity and dominance performance in juvenile brown trout (Salmo trutta L.).

12

JUN 2017

Paper: Flooding tolerance of floodplain meadow species depend on age

Posted by Daniel Nyqvist | Karlstads universitet

A floodplain meadow.

The scientific article ”Flooding tolerance of four floodplain meadow species depends on age” by Gattringer, Donath, Eckstein, Ludewig, Otte and Harvolk-Schöning was recently published in the journal PLoS-One. Lutz Eckstein, one of the coauthors, is a professor within the River Ecology and Management research group at Karlstad University, whereas the other authors represent Justus-Liebig-University Giessen and Kiel University.

In then the abstract the authors write: ”Numerous restoration campaigns focused on re-establishing species-rich floodplain meadows of Central Europe, whose species composition is essentially controlled by regular flooding. Climate change predictions expect strong alterations on the discharge regime of Europe’s large rivers with little-known consequences on floodplain meadow plants.

In this study, we aim to determine the effects of flooding on seedlings of different ages of four typical flood meadow species. To this end, we flooded seedlings of two familial pairs of flood meadow species of wetter and dryer microhabitats for 2 weeks each, starting 2, 4, 6, and 8 weeks after seedling germination, respectively.

We show that a 2-week-flooding treatment had a negative effect on performance of seedlings younger than 6 weeks. Summer floods with high floodwater temperatures may have especially detrimental effects on seedlings, which is corroborated by previous findings. As expected, the plants from wet floodplain meadow microhabitats coped better with the flooding treatment than those from dryer microhabitats.

In conclusion, our results suggest that restoration measures may perform more successfully if seedlings of restored species are older than the critical age of about 6 weeks before a spring flooding begins. Seasonal flow patterns may influence vegetation dynamics of floodplain meadows and should, therefore, be taken into account when timing future restoration campaigns.”

Access the paper online here: Flooding tolerance of four floodplain meadow species depends on age.

2

JUN 2017

Temperaturens betydelse under embryoutveckling hos vandrande fiskarter

Posted by Daniel Nyqvist | Vinterekologi

Karlstad Universitet skriver om NRRV:s forskning om temperaturens betydelse under embryoutveckling hos vandrande fiskarters livscykel. I artiklen, med titeln Nordiskt samarbete ger forskningspengar skriver de:

”Temperaturens betydelse under embryoutveckling hos vandrande fiskarters livscykel ska undersökas av forskare från Norge, Danmark och Sverige. Från Karlstads universitet är Larry Greenberg, professor i biologi på NRRV, Naturresurs rinnande vatten, ansvarig för studierna kring olika aspekter av fiskens beteende.

Det är den ökade temperaturen orsakad av global uppvärmning, särskilt under vinterhalvåret, som i våra nordiska vatten kan ha stor påverkan på fiskens livscykel. Detta kan vara särskilt viktigt för fiskar som lägger övervintrande ägg, som laxartade fiskar gör.

– En tidigare studie har visat att med samma mängd mat växer fisken som ung snabbare om deras ägg hade utsatts för en höjning på vattnet med 5 grader jämfört med de normala vinterförhållandena, säger Larry Greenberg. Detta kan leda till att fisken vandrar ut i en yngre ålder, vilket kommer att testas inom detta projekt.

Det här kan också ändra fiskens personlighet och det forskarna bland annat ska studera är om fiskarna blir blygare och mindre aggressiva vid en temperaturhöjning av vattnet under äggstadiet. Dessutom kommer forskarna att undersöka om en miljöförändring, som höjda temperaturer på vintern leder till så kallade epigenetiska förändringar, det vill säga förändringar i hur mycket eller hur lite olika gener uttrycks.

Det Norska forskningsrådet ger drygt sex miljoner kronor till det nordiska samarbetsprojektet som börjar 2017 och avslutas 2020.”

Läs mer om Larry Greenberg’s forskning om vintertemperaturens effekt på fiskars utveckling, fysiologi och beteende i blogg-artikeln: Early environmental effects on behavior and growth: Atlantic salmon in an altered climate.

1

JUN 2017

Early environmental effects on behavior and growth: Atlantic salmon in an altered climate

Posted by Daniel Nyqvist | Vinterekologi

Larry Greenberg, professor within the River Ecology and Management research group at Karlstad University, is currently studying how increased winter temperatures may affect Atlantic salmon development and subsequent behavior and physiology. Here he describes his research, and shares two videos (one in autumn temperature and one in summer temperature) used to measure (count) ventilation rates on Atantic salmon parr:

”Embryonic temperature conditions are expected to affect an organism’s behavior, as behavior is linked to traits such as metabolic rate and growth. Examining the effects of embryonic temperature is particularly relevant in today’s society as unprecedented rates of climate change are predicted to occur during this century, with a larger temperature increase expected in winter than in summer. Hence, climate change will most likely have large effects on ectotherms (cold-blooded animals) that overwinter their eggs, as is the case for salmonid fishes. The aim of this project is to study the effects of water temperature during the egg stage on the behavior, growth and metabolic rate of juvenile Atlantic salmon.

When it concerns metabolic rates, I hypothesized that elevated temperature during the egg stage will result in reduced standard metabolic rates for juvenile brown trout. Instead of measuring metabolic rates, I have measured breathing rates (ventilation rate), which has been shown to be correlated with metabolic rates. This was done in darkness when breathing rates are lowest, using an infrared-sensitive camera. The two film clips below show two different fish, both of which were raised at cold ambient water temperatures as eggs. One fish was filmed in 7 ^oC water and the other at 18 ^oC water.”

31

MAJ 2017

Paper: Stress responses of juvenile brown trout under winter conditions in a laboratory stream

Posted by Daniel Nyqvist | Vinterekologi

A juvenile brown trout in the experimental flume.

Johan Watz, postdoc at Karlstad University, recently published the scientific article ”Stress responses of juvenile brown trout under winter conditions in a laboratory stream” in the journal Hydrobiologia. In the abstract he writes: ”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.”.

Access the paper here: Stress responses of juvenile brown trout under winter conditions in a laboratory stream.

19

MAJ 2017

Seminar: Restoration of species-rich grassland – opportunities and obstacles

Posted by Daniel Nyqvist | Events

On Tuesday, 23 April, Tobias Donath from the Kiel University, will give a seminar on ”Restoration of species-rich grassland – opportunities and obstacles”. The seminar will be given at 14:30 in room 5F416 at Karlstad University.

Everyone is welcome to attend the seminar.

18

MAJ 2017

Jobb: Fältassistent inom dammutrivningsforskning

Posted by Daniel Nyqvist | Dam removal

Forskargruppen Naturresurs rinnande vatten vid Karlstads Universitet söker en eller två projektassistenter för arbete inom två forskningsprojekt på effekterna av dammutrivning. Det första projektet finansieras av KK-stiftelsen och bedrivs i Mörrumsån i samarbete med Sveaskog, Uniper vattenkraft och Power house, medan det andra projektet finansieras direkt av Karlstads universitet och bedrivs i Nianån, Gnarpsån och Enångersån (Hälsingland) i samarbete med Hudiksvalls kommun.

Projektassistenten/assitenternas arbetsuppgifter består i att i samverkan med övriga projektdeltagare genomföra fältaktiviteter som t.ex. telemetristudier på vandrande fisk, elfiske, provtagning av bottenfauna, inventering av växtsamhällen och bidra till att sammanställa insamlad data.

Läs mer om tjänsterna, och ansök, på Karlstads Universitets rekryteringshemsida. Sista ansökningsdag är den 24 maj, och anställningarna är tidsbegränsade. Mer information om projekten finns i bloggartiklarna Dammutrivning och fiskvänliga turbiner (Mörrumsån) och Dammutrivning i Gnarpsån och Nianån.