NRRV i media

Posted by Daniel Nyqvist | Nyheter

Under sommarmånaderna har NRRV-forskares arbete eller expertis uppmärksammats i olika media. Hallandsposten skrev om passagestudier med ålyngelstudier i Laholm och intervjuade Jonas Elghagen, Lutz Eckstein intervjuades angående den invasiva lupinen i Värmlands Folkblad,och en av Anders Nilssons senaste artiklar – om hur mört-braxen-hybrider är känsligare för predation än braxen och mört –  uppmärksammades av The Economist.

The principle behind downstream fish passage solutions using low sloping intake racks. The fish is swept and guided a long a beta rack to a bypass at the racks downstream end.

Hydropower dams block migration routes and disrupt longitudinal connectivity in rivers, thereby posing a threat to migratory fish species. Various fish passage solutions have been implemented to improve connectivity with varying success. For downstream migrating fish, low sloping turbine intake racks are used to guide fish to bypasses. Current knowledge, however, is based on hydropower plants with intake capacities <72 cms. There is also a trade-off between electricity generation and fish guidance (smaller bar spacing – better for fish, larger bar spacing – better for hydropower). Currently, gap widths/bar spacings of 10-20 mm are recommended but behavioral guidance effects open up the possibility of larger bar spacings.

During the autumn, Karlstad University in collaboration with Vattenfall and NINA will, experimentally study the behavior and passage performance of downstream migrating eels approaching a variety of low sloping intake racks. The experiments will be conducted in a new large experimental flume – Kungsrännan – at Vattenfalls laboratory in Älvkarleby. We will study the passage behavior and performance of eels for alpha racks – inclined from the bottom up – and beta racks – angled from one side of the channel to the other – with different gap-widths (10-30 mm).

For this, we are looking for one or two interested and ambitious laboratory assistants to join us in Älvkarleby. The assistants will be salaried and needed from September to November. Housing in the area can be provided. Are you interested in joining us? Contact Olle Calles or Daniel Nyqvist for more information.

On 28-29 August, 2017, a workshop on ”Research and Teaching for Sustainability and Stewardship will be organized at Karlstad University. The workshop’s goals are to ”introduce sustainability and stewardship topics to faculty and students at Kau and to develop research and teaching collaborations for future projects.”  The first day will be spent on presentations about international perspectives of sustainability and stewardship. On the second day Karlstad University’s Education for Sustainable Development and Service Research Center research groups will present some of their related research. See detailed schedule below:

Monday 28 August

13.15: Ricardo Rozzi, University of North Texas, USA & Universidad de Magallanes, Chile: Earth Stewardship and biocultural ethics”

13.45: Shan Gao, Soochow University, China: ”Environmental Ethics: A perspective from China”

14.15: Maria Teresa LaValle, UNTREF/SADAF, Argentina: ”A perspective from Argentina”

14.45: John Piccolo, KAU: ”A moral compass for planetary boundaries”

15.15: Coffee break

15.45 – 17.00 Discussions 

Tuesday 29 August

10.00: Niklas Gericke, KAU: ”The effect of education for sustainable development in the Swedish school system”

10.30: Teresa Berglund/Daniel Olsson, KAU: ”Case studies in Education for Sustainable Development”

11:00: Bo Enquist & Samuel Petros Sebhatu, KAU: “Stewardship and Hyper norms for Systemic Governance in Global Society”

11.30: Discussions

12.00: Lunch

13.15-15.00: Discussions

All talks will be given in Room 5F322, at Karlstad University. Everyone is welcome to attend the workshop. Register to if you wish to attend.

Rachel Bowes has recently joined the NRRV-research group. Here she writes about her previous work and what she intends to do as a postdoc at Karlstad University:


Rachel Bowes (right) with Brendan Martin, sampling algae.

”Hello! I’m Rachel Bowes and I am so excited to be joining NRRV! I just wanted to take a moment and tell you a little about me and my previous research. I have always had a deep appreciation and fascination for the natural world, and this has developed over the years into an insatiable desire to learn everything I possibly can about it. Not only do I want to discover, but I want to share these findings with everyone, and protect the Earth that I care about so much.

I completed my doctorate in May 2016 from the Department of Ecology and Evolutionary Biology at the University of Kansas (KU). My dissertation was entitled: Temporal Analysis of River Food Webs. Rivers and their tributaries are the arteries of the planet, pumping freshwater to wetlands and lakes and out to sea. Understanding energy flow up trophic levels, nutrient cycling pathways, and relative importance of terrestrial and aquatic carbon sources supporting aquatic consumers in large river food webs is essential in planning for wildlife conservation, environmental protection, and floodplain management. The principal goal of my dissertation was to understand better the factors controlling the complexity of river food webs through time.


Rachel Bowes (right) with Holly Lafferty, seining for fish in the Kansas River.

At a shorter time scale, I first looked at how season and food availability affect fish in rivers. I employed bulk tissue stable isotope analysis to determine trophic position of fish in the field, over different seasons, and fish in the lab, under different amounts of nutrient stress.

In the remaining chapters of my dissertation, I utilized a new technique, applying nitrogen and carbon stable isotope analysis of amino acids to samples to determine trophic position and carbon food sources over time.  First, I demonstrated the utility these new methods in a controlled feeding experiment in the laboratory, determining fish trophic positions. I showed that the new methods seemed to offer more accuracy and precision in trophic position estimates when compared to more traditional methods of bulk tissue isotope analysis. With these new analytical methods, I proposed multidimensional metrics for use with compound specific analyses of food webs, as well as other multidimensional community measures (e.g., fatty acids, ordinal traits). Then, I evaluated long-term historical changes in trophic position and food sources of fish museum specimens using amino acid stable isotope analyses of both the Mississippi and Ohio rivers.


Rachel Bowes (right) in the laboratory at University of Kansas.

Rivers are among the most extensively altered ecosystems on earth. Over 60% of the world’s large river basins are now affected by dams for irrigation, urban development, navigation, and energy production. Many countries are recognizing the negative implications of these impoundments and are now actively removing dams. For my post-doc research here at Karlstad, I will be using my expertise in stable isotopes to look at river connectivity and the implications of dam removal on river ecosystems. There are several potential facets that we will be looking at, including fish movement, population genetics, and transfer of nutrients from marine to freshwater to terrestrial ecosystems. Stay tuned for more developments coming soon!

If you want to follow my current research and its progress, learn more about specific projects I have been involved in previously, or read about my diverse teaching experiences, please visit my website: You can also follow me on Twitter @EcologyRachel.”

2012-08-15 14.06.19

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

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


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:


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.).



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.

fiskkauKarlstad 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.