Brown trout (Salmo trutta) eggs with eyed embryos

On Tuesday 8 December Kalle Filipsson, RivEM PhD student, will present his work on how elevated temperatures and predator presence during egg incubation affect development and behaviour of brown trout. The seminar starts at 13:15 and will be streamed live on Zoom. Contact Kalle ( if you are interested in attending the seminar, and he will send you a link.

Johan Watz, David Aldvén, Antonis Apostolos Brouziotis, Niclas Carlsson, Eirini Karathanou, Kristine Lund‐Bjørnås, Gustav Lundqvist, Martin Österling, John J. Piccolo and Olle Calles recently published the paper “Social behaviour of European grayling before and after flow peaks in restored and unrestored habitats” in the journal River Research and Applications.

In the abstract of the paper the authors write:

“Cost‐effective implementation of fish‐friendly hydropower flow operation and habitat restoration measures require an understanding of their effects on fitness‐related behaviours of stream fish. Here, we investigated how changes in flow and bottom structure influence the social behaviour of European grayling, using large experimental flumes (700 L s−1), with and without added boulders (i.e., restored and unrestored habitat). Grayling increased their distance to nearest neighbour at the start of flow ramping up and after a flow peak compared to stable base flow. At the start of ramping up the flow, grayling made less position changes (movements >1 m) than at stable base flow and after a flow peak. In the unrestored habitat, the proportion of time grayling spent actively swimming was lower before a flow peak than it was both at the start of ramping up the flow and after the peak, an effect not found in the restored habitat. In addition, we compared two static flows, and habitat restoration mediated their effect on distance to nearest neighbour. Grayling in the restored habitat were positioned closer to each other in the low (~10 cm s−1) than in the intermediate static flow (~40 cm s−1), whereas in the unrestored habitat, grayling showed the opposite pattern. Moreover, grayling reduced their number of position changes in the intermediate static flow, which was reflected by a reduction in active swimming. Stomach analysis after the trials revealed that foraging success was higher in variable than in the stable flow treatment. These results show that flow magnitude, flow changes and instream structure play important roles in the behaviour of stream fishes.”

The paper is available open access on the journal website.

Johan Watz (left), together with Eirini Renata Karathanou and Antonis Apostolos Brouziotis.

On Tuesday 26 May Roman Motyka, NRRV PhD student, will give a seminar entitled “The role of behavior and habitat use in conservation biology of the European eel (Anguilla anguilla). During this seminar, Roman will present his plans for his PhD project.

The seminar starts at 13:15 and will be held online and streamed via the video communication system Zoom. Everyone who wants to attend the seminar are welcome to do so. We will not distribute the zoom link to the seminar publicly online. If you want to attend the seminar, contact Roman ( or Olle Calles (, and they will send you a zoom link so that you can participate.

Roman Motyka (right) and Tobias Knieps (left) with some eels in a net.

As a member of the European consortium RIBES (River flow regulation, fish Behaviour and Status), the River Ecology and Management research group at Karlstad University invites applicants to three PhD positions on fish migration and passage in regulated rivers. In addition to the three PhD positions in Karlstad, RIBES also announces 12 more PhD positions in Belgium, Estonia, Germany, Italy and the UK as part of the same network.

Read more about the PhD positions and how to apply here!

Last application date is 31 May 2020.

To be eligible for one of the PhD positions in Karlstad, candidates cannot have resided in Sweden for 12 months or longer in the 3 years immediately before the recruitment date.

For more information about RIBES, check out our website!

River Klarälven in Värmland, Sweden

On Friday 13 March, Kalle Filipsson, NRRV PhD-student, will defend his (my) licentiate thesis. The thesis has the title ”From behaviour to genes: anti-predator responses of brown trout (Salmo trutta) under winter conditions”. The defense will be held in room 1B309 (Sjöströmsalen) at Karlstad University, and starts at 10:00. Stefán Óli Steingrímsson, Professor at Hólar University, Iceland, is the opponent. The defense is open for everyone who wishes to attend.

Kalle’s licentiate thesis, nailed to one of the “theses trees” at the Biology Department at Karlstad University.
Three juvenile brown trout (Salmo trutta), doing trout stuff in a stream flume at Karlstad University.

On Tuesday 25 February, Kalle Filipsson, RivEM PhD student, will give a seminar entitled ”From behaviour to genes: anti-predator responses of brown trout under winter conditions”. The seminar starts at 13.15 in room 5F416, everyone who wants to is welcome to attend the seminar.

This seminar is a practice seminar in preparation for Kalle’s (my) licentiate defense, which will be held Friday 13 March at 10:00. More information about the licentiate seminar will be provided closer to the defense.

Juvenile brown trout (Salmo trutta). Photo: Karl Filipsson
A burbot (Lota lota) in a stream flume at Karlstad University. Photo: Karl Filipsson

Arctic charr habitat in northern Iceland.

On Tuesday 5 November, Stefán Óli Steingrímsson, Professor at Hólar University College, Iceland, will visit Karlstad University and give a seminar titled “Salmonid behaviour in space & time: Some lessons from Iceland”. The seminar starts at 13:15 in room 5F416 at Karlstad University. Everyone who wants to are welcome to attend the seminar.

Hjaltadalur valley on northern Iceland, seen from Hólar.

On Tuesday 5 March (tomorrow) Anna Hagelin, PhD student at Karlstad University, will give a pre-dissertation talk titled “Conservation of landlocked Atlantic salmon in a regulated river: behaviour of migratory spawners and juveniles”. The seminar starts at 13:15 in room 5F416. Everyone is welcome to attend the seminar.

Anna will defend her doctoral thesis on 12 April at 10:00 in room 1B309 at Karlstad University. More information will come closer to the dissertation.