European eel, Anguilla anguilla

On Tuesday 18 June, Niclas Carlsson, lab/field technician and master student at Karlstad University, will give a seminar titled: “Low-sloping racks and the importance of bar spacing for eel passage”. The seminar starts at 13:15 in room 5F416 at Karlstad University. Everyone who wants to are welcome to attend the seminar.




Daniel Nyqvist, Jonas Elghagen, Marius Heiss and Olle Calles recently published the article “An angled rack with a bypass and a nature-like fishway pass Atlantic salmon smolts downstream at a hydropower dam” in the journal Marine and Freshwater Research.

In the abstract, the authors write:

Hydropower dams disrupt longitudinal connectivity and cause fragmentation of river systems, which has led to declines in migratory fish species. Atlantic salmon smolts rely on intact longitudinal connectivity to move downstream from rearing habitats in freshwater to feeding grounds at sea. Smolts often suffer increased mortality and delays when they encounter hydropower plants during their downstream migration. Currently, there are few examples of downstream passage solutions that allow safe and timely passage. We assessed the performance of two passage solutions at a hydropower dam, namely, an angled 15-mm rack with a bypass and a large nature-like fishway. The performance of these new fish passage solutions was evaluated by tracking radio-tagged Atlantic salmon smolts as they encountered the facilities. The radio-tagged smolts passed the dam 9.5 h after release (median) and exhibited a dam-passage efficiency of 84%, with passage rates increasing with body length. Fish passage occurred through both the rack bypass and the naturelike fishway. The passage efficiencies were 70–95% for the rack bypass and 47% for the nature-like fishway. The new fish passage facilities resulted in improved passage conditions at the site, confirming that angled racks with bypasses as best practise solutions for downstream passage, but also that large nature-like fishways may act as downstream passage routes for salmon.

Access the paper here, or contact any of the authors.

Amy Newsom on lake Alstern.

In August and September 2018, Amy Newsom from Germany visited Karlstad University and did an internship with NRRV. Here she writes about her months at Karlstad University.

“Having spent a year at Karlstad University as an exchange student in 2017 in the framework of my bachelor program “Environmental and Sustainability Studies” at the Leuphana University in Lüneburg, Germany, I had already been able to gain a first impression of the university’s biology department, which sparked my interest in freshwater ecology. Consequently, I was thrilled to have the opportunity to join the Naturresurs rinnande vatten Team for a six-week internship in August and September of 2018.

During the weeks I spent at Karlstad University, I was able to work with different researchers, getting to know a variety of projects and greatly extending my previous knowledge on freshwater and riparian ecology, in particular river connectivity. My main aim in this internship was to gain more practical research experience, so I was glad to be able to spend a lot of time both in the lab and in the field. For example, my work included processing raw data on the ventilation rates of young trout to assess differences in metabolism efficiency, counting the eggs of spiders gathered in the field and preparing samples for stable isotope analysis to assess the impact of hydro dams on food web interactions of fish. This was a particularly interesting experience as stable isotope analysis was a new scientific procedure to me, and I was keen to learn more about it. I was also excited to join in some of the field work conducted during my time at NRRV, collecting fish, invertebrates and plankton samples from the lake Alstern and electrofishing in the rivers Mörrumsån and Emån to assess the overall community composition at different sites. I was furthermore able to gain valuable insights into the design of research experiments while accompanying the setting up of an experimental flume in Älvkarleby and the preparation of eel traps in the river Alsterälven. In the time I spent in the office, I was also able to gather more experience in data analysis and scientific writing, both helpful preparations for my upcoming bachelor thesis.

Amy Newsom dissecting a crayfish.

Returning to Karlstad also gave me the opportunity to improve my Swedish, reconnect with old friends and make new contacts, as well as further explore the forests, rivers and lakes in the area that I have come to love so much. My thanks go out to John Piccolo, on whose invitation I was able join NRRV as an intern, the International Offices both in Karlstad and at my home university for helping me with the administrative process, and the German foundation Meifort Stiftung, whose generous support made this internship possible for me. I am also incredibly grateful to all the researchers at the KAU biology department who warmly welcomed me into their team, took the time to introduce me to their work and helped me gain new knowledge and experience, in particular Olle Calles, Rachel Bowes, Larry Greenberg, Denis Lafage, Karl Filipsson, Andrew Harbicht, Lovisa Lind and Niclas Carlsson.”

Amy Newsom and Andrew Harbicht (NRRV-postdoc) electrofishing in river Mörrumsån.

A cutthroat trout (Oncorhynchus clarkii).

On Monday October 8, Guillermo Giannico, Associate Professor at Oregon State University, will give a seminar titled:Fish Passage and Habitat Restoration: a Priority Setting Approach from Coastal Oregon, U.S.A”. The seminar will start at 13:30 in room 5F322 at Karlstad University. Everyone is welcome to attend the seminar.

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 Herting dam with the low sloping intake rack in the intake channel to the left and the large nature-like fishway to the right. (Photo from Fiskevårdstekniks film)

Recently, the paper “Upstream and downstream passage of migrating adult Atlantic salmon: Remedial measures improve passage performance at a hydropower dam” was published in the journal Ecological Engineering. The paper was authored by Daniel Nyqvist, Anders Nilsson, Ingemar Alenäs, Jonas Elghagen, Mats Hebrand, Simon Karlsson, Stefan Kläppe and Olle Calles. They summarize the paper: “Habitat connectivity is central for life-cycle progression for migrating organisms. Passage of hydropower dams is associated with mortality, delay, and migratory failure for migrating fish, and the need for remedial measures to facilitate passage is widely recognized. Lately, nature-like fishways have been promoted for upstream migrating fish, and low-sloping turbine intake racks for downstream migrating fish, but evaluations of these remedial measures are largely lacking. At Herting hydropower dam in southern Sweden, a technical fishway for upstream migrating salmonids, and a simple bypass entrance/trash gate for downstream migrating fish have been replaced by a large nature-like fishway for up and downstream migrating fish, and a low-sloping rack, guiding downstream migrating fish to the bypass entrance, has been installed. In this study, we evaluated these remedial measures for adult Atlantic salmon, spawners and kelts, in a before/after improved remedial measures radio telemetry study. Passage performance was improved for both up- and downstream migrating adult Atlantic salmon after remedial measures. Passage rate increased for fish migrating in both directions, and overall delay decreased while overall passage efficiency increased for upstream migrating fish. After the improved passage solutions almost all tagged fish passed the dam with very little delay. Before modifications, upstream passage performance through the technical fishway was higher at higher temperatures, at day compared to night, and for males compared to females. No such effects were observed for the after-measures nature-like fishway, indicating good passage performance for both sexes under a wide range of environmental conditions. Similarly, for downstream migrating kelts, discharge positively affected passage rate before but not after the fishway modifications. Altogether, our work demonstrates the possibility of coexistence between hydropower and Atlantic salmon in a regulated river.”

Access the paper here. For questions, e-mail the authors.

Fish Passage 2017 – International Conference on Engineering and Ecohydrology for Fish Passage will be held in Corvallis, Oregon, USA on June 19-21 2017. The confererence “…promises to be an important international forum for researchers and practitioners to exchange findings and experiences on fish passage issues.

Fish Passage 2017 will be of interest to researchers, educators, practitioners, funders, and regulators who have an interest in advancements in technical fishways, nature-like fishways, stream restoration and stabilization, dam removal, and the myriad of funding, safety, climate change, and other socio-economic related issues surrounding connectivity projects.

This is a three-day conference with concurrent sessions in engineering, biology, management and monitoring techniques. The conference will also feature plenary talks, professional networking opportunities, and a poster session. Independently offered short courses, workshops and tours will be available immediately before and/or after the conference.”

Plenary speakers will be say’ay’ – John Eli Sirois, Futoshi Nakamura, Tony Farrell, Paul T. Jacobson, and Kurt D. Fausch. Read more about the plenary speakers here. Also, pre-conference short courses and post-conference tours are available. Read more about the conference at




nyqvist2016cLast Friday, I, Daniel Nyqvist, successfully defended my PhD-thesis “Atlantic salmon in regulated rivers – Migration, dam passage, and fish behavior” at Karlstad University. Scott Hinch (University of British Columbia, Canada) was opponent and Eva Thorstad (NINA, Norway), Kim Aarestrup (DTU AQUA, Denmark) and Hans Lundqvist (Swedish University of Agriculture) constituted the grading committee (betygskommitté). The short abstract of the thesis reads:

“Hydropower dams block migration routes, thereby posing a threat to migratory fish species. Fishways and other fish passage solutions may aid fish to pass hydropower dams. A functional fish passage solution, however, must ensure safe and timely passage for a substantial portion of the migrating fish. In this thesis, I focus on downstream passage and evaluate the behavior and survival of migrating Atlantic salmon in relation to dams in systems with (1) no fish passage solutions (2) simple passage solutions (3) best available passage solutions. In addition, I studied the survival and behavior of post-spawners and hatchery-released smolts.

A large portion of the spawners survived spawning and initiated downstream migration. For hatchery-reared smolts, early release was associated with faster initiation of migration and higher survival compared to late release. Multiple dam passage resulted in high mortality, and high spill levels were linked to high survival and short delay for downstream migrating salmon. For smolts, dam passage, even with simple passage solutions, was associated with substantial delay and mortality. Rapid passage of a large portion of the migrating adult salmon was achieved using best available passage solutions.”

The frame of the thesis is available here. Already published papers included in the thesis are Post-Spawning Survival and Downstream Passage of Landlocked Atlantic Salmon (Salmo salar) in a Regulated River: Is There Potential for Repeat Spawning? (in River Research and Applications) and Migratory delay leads to reduced passage success of Atlantic salmon smolts at a hydroelectric dam (in Ecology of Freshwater Fish). For full access to the thesis, contact


Radiotagged migrating brown trout.

Next week, Daniel Nyqvist, PhD-student at Karlstad University, will defend his (my…) thesis “Atlantic salmon in regulated rivers: migration, dam passage, and fish behavior”. The defense will take place on Friday, December 9th, at 10:15 in room 9C 203 on Karlstad University. The abstract and the frame of the thesis are available online here.

Scott Hinch (University of British Columbia, Canada) is the opponent and Eva Thorstad (NINA, Norway), Kim Aarestrup (DTU AQUA, Denmark) and Hans Lundqvist (Swedish University of Agriculture) constitute the grading committee (betygskommitté). The visiting researchers will give seminars at Karlstad University on Thursday, December 8th. The seminars start at 14:15 in room 5F322:

Scott Hinch: Using telemetry in adaptive management experiments at fish passage facilities

Eva Thorstad: New results on downstream migration of eel and salmon past power stations in Germany

Hans Lundqvist: Wild Baltic stocks of Atlantic salmon in northern Sweden: Where are we and where are we going in Umeälven?

Kim Aarestrup has yet to disclose the title of his seminar.

Everyone is welcome to attend both the PhD-defense and the seminars.

Yagi antenna used to study the movement of radio-tagged Atlantic salmon at the Edsforsen hydropower dam in the River Klarälven.

On 12-13 December, Theodore Castro-Santos from Conte Anadromous Fish Research Center (USGS) will give a course titled “Advanced Telemetry Techniques – Data Management and Analysis for Fish Passage Studies” at Karlstad University, Sweden. The two-day course is described further:

“Fish passage is about movement, and fish passage effectiveness can only be understood by measuring rates at which fish move past barriers. Telemetry is often the best tool for measuring effectiveness. Many studies, however fail to make optimal use of available data, and over-simplistic analyses can often lead to inaccurate conclusions. In this course we will discuss the three principle types of telemetry data (PIT, radio, acoustic), reviewing their common characteristics and challenges associated with managing the very large datasets these technologies can produce.

On the first day we will review study design concepts, and students will learn about relational database structure, optimal database design, and extraction of basic passage metrics (proportion entering, proportion passing). 

On the second day, we will delve deeper into analysis methods, with an overview and rationale for applying time-to-event analysis to passage data. This approach allows researchers to explicitly account for environmental covariates that change over time, address the problems associated with fish that are exposed to multiple and changing conditions, and show how these factors can be incorporated into metrics of passage performance without incurring bias. We will conclude by analyzing an actual fish passage dataset, exploring the strengths and limitations of the approach.

The course will be in English. Attendees should have decent computer skills and should come prepared with a laptop loaded with Microsoft Access and R (packages: Survival, Dplyr, Coxme, Ggplot2). These will be our primary tools as we move through the course material. Attendees are also encouraged to bring their own data and/or descriptions of previous or planned studies. We can use these as part of a discussion and critique of study design concepts.”

Schedule for the course:

Monday 12 Dec kl 8:30 -12:00 i room 5F323

Monday  12 Dec kl 13:00 -16:00 i room 5F416

Tisday  13 Dec kl 8:30 – 12:30 i room 5F 416.

The course is free to attend but requires registration. Registrate by e-mail to Larry Greenberg (