Although most fieldwork is carried out in warmer seasons, members of the NRRV research group also go out in winter to collect information and samples for their research. Here, Richard Durtsche, visiting professor from Northern Kentucky University, writes about a field excursion that took place last week:

Andrew Harbicht, Post-Doc at Karlstad University (front) and Richard Durtsche, visiting professor from Northern Kentucky University, (back) at the field site.

“As part of a study on the energetics in natural food sources available to Salmonid fishes (trout, salmon, grayling, etc.), we have been sampling the macroinvertebrates in streams that connect to the Klarälven (Clear River) this past fall and now this winter. These investigations will focus on an increase in the accuracy of macroinvertebrate body size measurements taken with digital imaging and an increase in the accuracy of dry mass measures using an ultramicrobalance, newly acquired by Kau Biology. Energetic (caloric) content will also be determined for the different macroinvertebrate taxa. The three target macroinvertebrates groups for this study include mayflies (Ephemeroptera), caddisflies (Trichoptera), and stoneflies (Plecoptera). These are major prey items for all life history stages of Salmonid fishes, and are often used as indicators of stream health in aquatic environmental assessment due to their sensitivity to pollutants and anthropogenic impacts. Results of this study will be useful in developing energetic models of fish foraging for management of fish population and river/stream conditions.

The team that braved the cold winter conditions and moderate snow levels on January 29th included: Richard Durtsche (NRRV visiting professor from Northern Kentucky University), Rachel Bowes (NRRV Post-Doc), Andrew Harbicht (NRRV Post-Doc), and Rachel Prokopius (exchange student from Northern Kentucky University). The stream that we were investigating was located just south of Ransäter. The water was flowing rapidly, and we initially decided to check out the stream conditions on the downhill (east) side of highway 62 to look for sampling sites. There was knee deep (or more) snow to ford before coming to forest cover where moving was easier despite many treefalls. As the streamflow was fast and the water level high, there were no safe locations to sample. So we headed west of highway 62, just off the access road. There we found good sampling habitat just downstream of a large pool that ran under a bridge on that road.

Rachel Prokopius, exchange student from Northern Kentucky University, and Richard Durtsche, measuring the stream width and flow rates.

One of the first things we did at waterside, was to collect physicochemical measures of the water conditions. These included: temperature, pH, conductivity, and dissolved oxygen. We also measured the flow volume of water by measuring the width of the stream, and then taking the depth and flow rates every 50 cm across the stream. Water temps of 1.4°C and the tingle of cold penetrating our waders told us that today was not a good day to fall in the water. After we crossed the fast-flowing stream, we found several relatively shallow areas where we could sample invertebrates. We made a series of kick seine samples from different parts of the stream shallows to dislodge and collect invertebrates from the stones and substrate. 

It was definitely a group effort to kick stones and stream bottom, brush rocks to knock off invertebrates to be carried with stream flow into the seine, and then wash the samples into a collecting bucket. While we thought we might have limited luck, we in fact did extremely well with collecting a range of macroinvertebrates and large quantities of many of those taxa. There will be a good share of macroinvertebrate sorting and measuring upon return to the laboratory.”

Rachel Prokopius, Rachel Bowes, Post-Doc at Karlstad University, and Andrew Harbicht sampling invertebrates using a kick seine.


The team at work in the stream.


Richard Durtsche at the field site.


Close-up photo of a stonefly (Plecoptera) larva.


For the first Tuesday seminar of the year, Kristine Lund Bjørnås, PhD-student at Karlstad University, will talk about evidence synthesis in environmental science. The seminar will be held Tuesday 23 January at 13:15 in room 5F416 at Karlstad University. Everyone is welcome to attend the seminar.

In preparation for the seminar, Kristine writes:

”In these times of alternative facts and post truth, the role and authority of scientists in society is challenged. It is therefore important that we as scientists continue to improve our methods and communication – and one way of doing that is to increase interaction with the end-users of scientific findings. In environmental- and natural resource management, many important policy and practice decisions are not being taken based on the best available scientific evidence, even when that is an explicit management objective. For instance, in a questionnaire among conservation practitioners in England, the majority (77%) reported that they used “commonsense”, “personal experience” or “speaking to other managers” as their primary source of information prior to management actions (Sutherland et al. 2004). This might be because there is no clear understanding of what the best available scientific evidence (i.e. “what works”) is. As a response to this need for more evidence-based environmental management, systematic reviews have found their way also into environmental science.

Brown trout (Salmo trutta), the model species of Kristine’s dissertation project, in an aquarium at Karlstad University.

In this seminar I will go through the principles of systematic reviewing literature, the strengths and weaknesses of the method, and I will talk about my current review project.”


Sutherland, W.J.; Pullin, A.; Dolman, P.M. & Knight, T.M. 2004. The need for evidence-based conservation. TRENDS Ecol Evol. 19.6.

See also:

Mistra Council for Evidence-based Environmental management

Collaboration for Environmental Evidence

Dennis Lafage relatively recently started a postdoc within the NRRV-research group at Karlstad University. Here he briefly presents his background and what he plans to do during his postdoc:

My name is Denis Lafage. I recently started a post-doc in the NRRV group to work on aquatic/terrestrial exchanges. I started research after working 10 years in Nature Reserves and Conservation Agencies where I was specialized in terrestrial fauna monitoring and conservation (mainly birds, invertebrates, and bats), statistics, GIS and database management.

I completed my doctorate in 2014 from the Muséum National d’Histoire Naturelle de Paris (France). My PhD thesis was dealing with the impact of management practices and natural perturbations (mainly flooding) on arthropods (spiders and carabid beetles) and plants in meadows. It also included a study using remote sensing technics to map vegetation associations using satellite imagery.

I consider myself as a community ecologist with a particular focus on arthropods. In the NRRV group, I will particularly work on a meta-analysis on the landscape drivers of aquatic/terrestrial fluxes. I will mainly focus on studies using stable isotopes for diet partitioning. As I have a particular interest in what we could call ‘perturbation ecology’ I will also work on food webs after spring floods. I have also the chance to be the co-advisor of a PhD based in Norway aiming at forecasting the impact of climate change on fishing spiders repartition in Scandinavia. Finally, I will also be involved in various projects where my skills in terrestrial arthropod ecology are required.”

Read more about Denis Lafage on his blog

Denis Lafage, sampling spiders in Sweden.

Denis Lafage, in back, and a collegue, sampling vegetation in Nantes, France.

In Denis Lafage precious work, he has been counting birds (Flamingo) in Caramargue, France.

And capturing and counting bats in roosts (France).

The book, ”Brown Trout: Biology, Ecology and Management”, edit by Javier Lobón-Cerviá and Nuria Sanz was recently published. The book is described as ”a comprehensive guide to the most current research, history, genetics and ecology of the brown trout including challenging environmental problems”. John Piccolo and Johan Watz, both researchers at Karlstad University, have written the chapter Foraging Behaviour of Brown Trout: A Model Species For Linking Individual Ecology to Population Dynamics? They summarize their chapter as follows:

”Within the discipline of stream fish ecology, population-, community-, and even ecosystem-level patterns and processes have assumed an increasingly larger role in recent decades. It might be argued, however, that research on the behaviour of individual organisms ought still to play a major role in ecology; it is upon the individual, after all, that natural selection acts. Thus, one might reasonably expect that observing an individual fish’s behaviour should lead to robust conclusions about the fitness costs and benefits that animals must trade-off in order to achieve reproductive success. And ultimately, it is those individuals that achieve the greatest direct fitness that ought to, on average, drive the population-level processes that have attracted so much of stream fish ecologists’ attention in recent years. In linking behavioral- to population-level ecology, we are in luck when it comes to the brown trout – there is no stream fish species whose population ecology is better quantified, nor are there many species that have received more attention from behavioural ecologists. Thus we might consider the brown trout as a model species for developing the ecological understanding of how natural selection (e.g. individual, fitness-based decisions) acts to regulate stream fish populations. To forward this concept, a further development of a quantitative approach to foraging behaviour is warranted. In this chapter we review and synthesize the literature on brown trout foraging experiments with an eye towards identifying the knowledge gaps that remain to be filled in order for ecologists to quantify the fitness costs and benefits of foraging behaviour.”

The book is available (but expensive) here. For access to the specific book chapter, email John Piccolo or Johan Watz.

Andrew Harbicht recently started a postdoc within the NRRV-research group at Karlstad University. Here he briefly presents his background and what he plans to do during his postdoc:

”Hello, my name is Andrew Harbicht and I’m one of the new Post-Docs to have joined the NRRV. My research experience has primarily been focused on salmonids (rainbow trout, brook charr, and Atlantic salmon) and extends from fisheries modeling to population genetics and radio telemetry. I moved to Karlstad from Montreal, Canada, where I conducted my Ph.D. at Concordia University, working together with the US Fish and Wildlife Service on Atlantic salmon restoration in Lake Champlain. During that time we investigated the impacts of hatchery rearing and release techniques on the lifetime survival and dispersal rates of landlocked salmon and investigated the impact of a thiamine deficiency on the migratory capabilities of returning spawners.

My work with this group will focus on the implications of migratory barriers for longitudinal connectivity among Atlantic salmon populations in the Baltic Sea. With the ever-increasing efficiency of new hydroelectric turbines and the costs associated with maintaining outdated installations, more and more energy producers are opting to remove older facilities to focus their efforts on newer structures. The removal of such aging dams and other barriers to migration within rivers is undoubtedly a positive step for river connectivity, though exactly what changes will occur as a result of such actions is simply unknown in many situations. In fact, over the short term, the removal of barriers can cause as many changes as initial installation. In other situations, maintaining instream infrastructure may be the best option available to energy producer. In which case, including structures that permit fish passage is important, but which type of structure is best suited to the job isn’t always clear. Where several options exist, managers need access to accurate information to assist in their decision-making process.

With my project, I’ll be looking at the impact of removing a partial barrier to migration on the movement patterns of Atlantic salmon, as well as the river ecosystem itself in the Mörrumsån river in southern Sweden. Our holistic approach will monitor all levels of the ecosystem, from the mechanisms that shape river terrain (sedimentation) to the smallest bacteria (decomposition) and the largest predators (fish), as well as all things in between (food-webs). I will also be investigating the genetic consequences of changes in movement patterns that result from the removal of a hydroelectric plant. In another river, the river Emån, we’ll be assessing the performance of a new type of fish lift, and Archimedes screw, which permits upstream and downstream passage, all the while producing its own energy. If found to be effective, such devices could greatly improve connectivity in fragmented river landscapes.”

Andrew Harbicht (left) and William Ardren (right) releasing tagged fish in the Boquet River, a  tributary to Lake Champlain.

Andrew Harbicht tracking radio tagged Atlantic salmon.

The River Daugava flows through Russia, Belarus and Latvia and empties in to Gulf of Riga in the Baltic sea. Historically the river hosted an important Atlantic salmon population. Since the construction of large dams in the mid-20th century, the salmon has lost access to their historical spawning grounds and only a hatchery supported, sea ranched population remains. Salmon, has, however persisted as a cultural, and locally economically, important fish, and now the idea of restoring wild salmon to the River Daugava system is gaining followers.

A trap and transport solution – based on hatchery fish (that is, salmon released in the river as smolts, now returning to spawn) and/or release of eggs and fry – have been discussed as an initial solution. Here, returning spawners would be trapped, transported upstream dams blocking their migration, and released to continue their spawning migration. To study the potential of trapping and transporting returning hatchery fish Karlstad University, the Institute for Environmental Solutions and Latvenergo, are currently studying the spawning migration of trap and transported salmon spawners in the River Daugava. The spawners, caught by the commercial fishery, have been equipped the radiotransmitters and transported upstream of two dams and released in the River Ogre, a tributary to River Daugava. Now, their movements in the river are being tracked using a stationary automatic receiver and manual tracking. Fish are still moving in the river, but preliminary results show some fish gathering at potential spawning grounds, whereas others have fallen behind the downstream dam.

The Latvian tv show ”Makšķerē ar Olti” made a short documentary, mainly in Latvian but with informative images, about the study. It is available online here.

In a pilot-study, Oscar Askling studied salmon spawning and fallback behavior in the River Daugava 2014. Results of this study is available in the Master thesis: A telemetry study for reintroducing wild Atlantic salmon (Salmo salar L.) in the Daugava and Ogre Rivers, Latvia”.

Tagging an Atlantic salmon with an external radiotransmitter. (Photo: Marta Dievina)

Releasing a tagged salmon in the River Ogre, a tributary to River Daugava. (Photo: From the documentary by Nomad.)

Tracking radiotagged salmon in River Ogre, a tributary to River Daugava.

The tagging crew. From left, Daniel Nyqvist, Linda Buholce, Matiss Zagars, Marta Dievina, Marta Utane and Armands Roze repressenting Institute for Environmental Solutions, Latvenergo and Karlstad University.

Kristine Lund Bjørnås recently started a licentiate position within the NRRV-research group at Karlstad University. Here she briefly presents her background and what she plans to do during her licentiate:

”Hello! My name is Kristine Lund Bjørnås and I recently started a licentiate degree (which is ½ a PhD) within the NRRV group at Karlstad University. Like Klarälven I started in Norway before I slowly found my way to Karlstad. I grew up in a town called Melhus in Mid-Norway, with one of the country’s best salmon rivers – Gaula – as a neighbour. My interest in anadromous salmonid conservation arose naturally. I have since lived and studied in Trondheim, Ås, Reykjavík, Steinkjer, and Lund before moving to Värmland.

Before Kristine Lund Bjørnås started her licentiate position she volunteered at a bird ringing station in Southern Norway. Here they have caught and ringed a young male sparrowhawk.

In my licentiate project, I am studying the spatial ecology of brown trout in local streams. My goal is to pinpoint the most cost-effective and informative method to predict living conditions for juveniles under different flow regimes and after river restoration measures. Thinking back to my hometown river system, the main focus is on the adults of the anadromous trout populations and on their conditions for spawning. The conditions for juveniles is often overlooked, but for efficient conservation of these threatened populations, we need to consider both. Which brings me back to my project. I will test if it is possible to predict the distribution, density, and growth of juveniles using habitat and fitness-based models of increasing complexity. The simplest models use physical habitat and hydrology to estimate usable area of a stream section; the most complex models – so-called drift-foraging or net energy intake models – also incorporate food (drifting insects) and foraging theory. By adding spatial and temporal variations in drift concentration given a flow, the models can be made more realistic – although a model will always be a simplification of the entire complexity of the natural world. I am sure to make mistakes, but to avoid repeating previous ones, I am doing a review of studies attempting to model drift- foraging in streams. I will start my main fieldwork in the late spring of 2018. There will be opportunities to join in on that, so stay tuned!

Autumn field survey in Örebro county. Kristine Lund Bjørnås sampling with visiting professor Kurt Fausch in the background. Photo: Carola Gutfreund.

I did my Master in Conservation Biology at Lund University. I am very interested in the broad societal and ethical discussions that arise in conservation biology. I wrote my thesis on spatial variations and potential drivers of population trends of birds breeding along the Swedish coast – in general, “warm-adapted” bird species (measured in species temperature index STI) have increased while “cold-adapted” species have declined over the last 27 years.”

Welcome to NRRV: Richard Durtsche

Posted by Daniel Nyqvist | Nyheter

Richard Durtsche recently joined the NRRV-research group as a visiting professor from Northern Kentucky University, USA. Here he presents his background and some of his planned work at Karlstad University:

Richard Durtsche, visiting professor at Karlstad University.

My name is Richard Durtsche, and I am a visiting professor joining the Kau River Ecology and Management Research Group from Northern Kentucky University (NKU) where I am a Professor of Biological Sciences, the Director of the NKU Research and Education Field Station, and Curator of Vertebrate Collections. I am a physiological ecologist and herpetologist with research interests in the feeding ecology, nutrition, and physiology of amphibians, reptiles, and fish along with related impacts of invasive species; niche occupancy; and bioassessment of aquatic ecosystems. I am currently on a one-year sabbatical, and my goals include professional development and exploring new research focused on modeling of fish drift-feeding and the ecophysiology of stream fishes related to my previous work on the foraging ecology and metabolism in reptiles and amphibians. This program will also strengthen the collaboration of our recently established exchange program that now exists between NKU and Kau.

My research goals are to investigate new methodologies in foraging ecology and ecological modeling as a collaborator in studies of the eco-physiology of drift feeding and energetics in Salmonid fish (trout, salmon, etc.), and potential changes in their metabolism related to thermal changes (potential effects of climate change) during development. The first part of these investigations will focus on the increased accuracy in measurements of the mass for three different macroinvertebrate (mayfly, caddisfly, and stonefly) prey types of these fish determined from digital images. These image measurements will then be combined with caloric content measures of these prey to provide an energetic basis of these food sources. The results will then be used to 1) improve theoretical models of the energetics and drift feeding by these fish for the group’s on-going studies on stream fish ecology and management, and 2) provide a basis for using digital images, potentially from a smart device, for enhanced methods and more rapid measures to understanding how different foods can influence fish distributions, their growth and abundance. The second part of this investigation will focus on the effects elevated environmental temperature (i.e., climate change) has on the metabolism of developing fish. By evaluating fish raised at different temperatures from the same cohort of eggs, we will be able to determine the plasticity (epigenetic capacity) of these northern climate fish to altered thermal environments. Measuring metabolic capacities is one of the best ways to determine the fitness of these fish and if they have the capacity to deal with climate change.”

Tomorrow, 24 October, Richard Durtsche will give a seminar titled ”Amphibians, Wetland Aquatic Ecosystems, and the Impact of Invasive Plants”. The seminar will be given at 13:15 in room 5F416 at Karlstad University.

Kraftag ål är ett samarbete mellan Vattenkraftföretagen och Havs- och vattenmyndigheten, och utgörs av åtgärder men även forsknings- och utvecklingsinsatser för att öka ålens framgång i utbyggda vattendrag. Kraftag åls slutseminarium arrangeras den 21 November i Stockholm, och organisatörerna bjuder in till att ”ta del av ny kunskap från utvecklingsprojekt och hör om frivilliga åtgärder som gjorts för ålen i vattendrag och vid kusten”. Seminariets presentationer behandlar bland annat fysiska avledare för nedströmsvandrande fisk, för ålen skonsam kraftverksdrift, möjligheter att övervaka ålvandringen, transporter av blankål och utsättning av ålyngel. Läs seminariets hela program, och anmäl dig, här:

Tomorrow, 26 September, Rachel Bowes, postdoctoral researcher at Karlstad University, will give a seminar on ”Temporally analyzing river food webs”. The seminar will be given at 13:15 in room 5F416 at Karlstad University. Everyone is welcome to attend the seminar.