On tuesday 27 October (tomorrow) Patrik Andreasson (Adjunct Professor, Luleå University of Technology; Specialist, Vattenfall AB) will give a seminar titled “Fish diagnostics by image recognition using machine learning (AI)”.

The seminar starts at 13:15 and will be held via zoom. Everyone who wants to are welcome to attend the seminar. Contact Olle Calles (olle.calles@kau.se) to receive a zoom link to the seminar.

Image recognition using AI, as a tool for fish identification, was mentioned on the Swedish news earlier this year. Follow this link to svt.se to watch a short video and to read more about the project (in Swedish).

Louis recently started his PhD at Karlstad University. Here, he writes about his previous work and what he intends to do as a PhD student at Karlstad University:

Hei! My name is Louis Addo. I recently joined the RivEM research group as a new PhD student. My background and skills cut across agricultural engineering (from University of Ghana, Legon-Ghana), hydropower development (from Norwegian University of Science and Technology), water engineering and fish habitat modeling (from University of Oulu). My experience with fish habitat modeling was with Finland’s Centre for Economic Development, Transport and the Environment (Ely-Center) in Oulu. With Ely-Center as a master’s thesis worker and later a 1 month contract as an environmental designer, I researched on the effects of short-term regulation on habitat conditions of brown trout, Salmo trutta in the lowermost part of the Kalajoki River (a river located in the Northern Ostrobothnia region of Finland) and possibilities for mitigation. This project was an eye-opener to the use 2D hydrodynamic modelling and fish habitat modelling as a river management tool to protect the river ecosystems of trout under hydropeaking conditions.

As a new PhD student with the RivEM research group, my contribution will mainly be directed towards ecological and individual-based modelling of river ecosystems. This will directly involve modelling of Atlantic salmon and brown trout habitat in the lower part of the Gullspång River (a tributary to the lake Vänern in Sweden) under hydropeaking conditions. It is my future desire that the outcome of this research will contribute to solving real-world conservation problems related to river ecosystems. My supervisors will be John Piccolo (professor), Johan Watz (docent), and Steve Railsback (adjunct professor). As hobbies, my passion for flying and general aviation drives me to fly drones although not a pro yet 🙂 I love to watch and play soccer as well.

Our former PhD student Anna Hagelin and several other researchers, amongst them Larry Greenberg, Olle Calles and Eva Bergman, recently published a new paper in the Canadian Journal of Fisheries and Aquatic Sciences.

They examined fishway passage of landlocked Atlantic salmon in River Klarälven, Sweden and brown trout in River Gudbrandslågen, Norway, and the influence of prior experience on passage success in 2012 and 2013. Fishway trap efficiency varied from 18 to 88% and was influenced by river discharge. Most salmon (81%) entered the fishway trap on days without spill, and salmon moved from the turbine area to the spill zone when there was spill, with small individuals showing a stronger reaction than large fish. Analysis of fish with and without prior trap experience showed that a higher percentage of the “naïve” fish (70% of salmon and 43% of the trout) entered the fishway traps than the “experienced” ones (25% of the salmon and 15 % of the trout). Delays for fish that entered the trap ranged from 3-70 days for salmon and 2-47 days for trout.

The paper is not publicly accessible, but can be requested via ResearchGate.

Veli recently started her PhD at Karlstad University. Here, she writes about her previous work and what she intends to do as a PhD student at Karlstad University:

Hello, hello! My name is Veli and I am one of the many new PhD students joining the RivEM band. My project is part of the MSCA-RIBES (River flow regulation, fish behaviour and status) and will aim to develop new guidance devices for downstream migrating fish. I will be hosted officially by Norconsult, but I will be actually based at Karlstad University. My main supervisor is Larry Greenberg, and I will be also under the co-supervision of Ann Erlandsson and John Piccolo at Karlstad, while Axel Emanuelsson is the Norconsult supervisor.

 I was born in Bulgaria during communism when the typical pastime was to wait at very long lines in front of the shops from early in the morning to try and buy some milk (one of my earliest memories). My parents are windsurfers and while my sister followed in their footsteps and became a professional windsurfer, I was always more interested in what was going on beneath the surface and would often get away from the coast, abandon the surfboard and dive to spot some fish and check how deep it was. Since the love for the sea was deeply drilled into my heart, when the time came to start thinking about a career path, the idea of becoming marine biologist felt the most natural.

Veli at age 8, heading into the sea with oversized windsurf equipment.

I started my bachelor degree in marine biology at Queen’s University, Belfast and in my final year I chose a project on fish aggressive behaviour, since I have been interested in the topic since I was a child. Me and my dad were always figuring out ways to minimise the aggression between our tropical aquarium’s fish, using see-through partitions when passions escalated and when introducing newcomers. The bachelor project examined if fish use a preferred lateral position when displaying to an opponent. After analysing hundreds of videos of convict cichlids duels, it became clear that they appeared to escalate only after ‘head to tail’ position and never from ‘head to head’, which had serious implications for previous fish aggression studies done with mirrors.

I was keen to investigate the mirror situation further and so I obtained a grant from the Fisheries Society of the British Isles (FSBI) and set up an experiment comparing one focal fish’s displays when presented with a real opponent and with a mirror. The experiment was further continued by a bachelor student and the results were eventually published in Animal Behaviour.

After the bachelor degree I wanted to gain some field experience and so I left for Istanbul to help a PhD student with gathering behavioural data on cetaceans to study how they are affected by marine traffic in the Bosphorus strait. The internship made me even more interested in animal behaviour so I decided to go back to university and start a masters in animal behaviour and welfare.

During my masters I became more interested in exploring different visual behaviour questions and so I chose a research project investigating if bats can see polarized light. The experiment was carried out in a Y- maze but also had fieldwork component, taking place at Max Plank’s Siemers Bat Research Station in Bulgaria. Even though my laboratory experiments were not conclusive due to the limited time period for research on the animals, the field experiments carried out by my colleagues at the research station seemed to conclude that the bats do indeed see polarization and use it to navigate, making them the first mammal to do so (making the findings Nature material).

After the masters degree I comleted an ERASMUS + placement program in Spain studying the effects of whale watching vessels on cetacean behaviour in the Gibraltar strait, where I helped with the collection and analyses of data and photo ID material.

Shortly after the end of the placement I left for the Hondurian cloud forest of Cusuco National Park as part of ongoing conservation expedition Operation Wallacea, where I worked as camp manager and I was more on the logistical side, however I got to dip my toe in all the different ongoing  terrestrial surveys, such as collecting Chytrid fungus samples from the endemic amphibians, bird and bat surveys in the park, etc. I went back to Cusuco for another expedition again a couple of years later in 2016.

After 9 years abroad, in 2015 after learning that a young family member is ill, I decided to go back to Bulgaria, so that I can be close to my family. In couple of weeks I organised a campaign to raise funds for the treatment and decided to do a solo cycle from Lisbon to my home city Sofia as a crowdfunding challenge. I made it home after 65 days, raised enough funds towards my cousin’s treatment and today she is in remission.

Collage from the 5000 km cycle challenge that raised over 6000 euro.

Once back to my home country I tried to be as involved as possible by being active citizen and organising and participating in science related and environmental protests. After becoming clear that no one else was going to do it, I organised The March for Science in Sofia, the only Bulgarian protest associated with the international demonstrations.

March for Science, Sofia, 2017

In 2018 I was part of the team of the Wind2Win challenge, where my sister and her partner did a historic crossing of the 300 km Bulgarian coast with windsurfs in 3 days to raise awareness of the plastic pollution problem in the Black Sea. I was part of the science team on the safety vessel and we were taking water ecological samples with a sonde and making cetacean and floating debris observations during the crossing. A documentary was made about the challenge, in order to help raise awareness among the public (teaser) with an upcoming online premiere. Under the initiative more than 6 clean ups have been carried out lifting around 3 tonnes of plastic from various beaches.

In my free time you can catch me in nature with my family, or trying out something new.

I am currently working at an eel experiment at the Älvkarleby flume and when free I go to Germany, where my family lives, but I look forward to moving to Karlstad and getting to know everyone soon.

Florian Stein, Director of Scientific Operations for the Sustainable Eel Group

On Tuesday 13 October (tomorrow), Florian Stein will give the seminar “The illegal trade in European eels from Europe to Asia”. Florian works as Director of Scientific Operations for the European organization Sustainable Eel Group (SEG). His main focus is on the illegal trade in European eels from Europe to Asia. During his seminar, Florian will talk about the global trade with European eel and law enforcement in relation to this trade.

The seminar starts at 13.15 and will be streamed live over Zoom. Contact Olle Calles (olle.calles@kau.se) to receive the zoom link to this seminar.

Read more about the Sustainable eel group here:

European eels, Anguilla anguilla

Sam Shry recently started his PhD at Karlstad University. Here he writes about his previous work and what he intends to do as a PhD student at Karlstad University:

Hej! My name is Sam Shry and I am another new PhD student just starting in the RivEM research group. Like Sebastian, I will also be working under the EU project LIFE Connects, but my primary research focus will be Atlantic Salmon and their migratory response to river restoration and re-connectivity. My main supervisor is Olle Calles, with assistant supervisors Martin Österling, Gustav Hellström (SLU), and Anders Nilsson (Lund University).

I am originally from Arkansas in the US, but have lived in Sweden for the last four years. I became interested in fisheries when I was working on my bachelor’s degree at the University of Arkansas at Little Rock. Inspiring teachers and amazing internship experiences motivated me to pursue a career in fisheries. After graduation, I worked for the U.S. Fish and Wildlife Service as a field technician, working primarily with salmonid management and monitoring in the mid-Columbia River.

Typical day working as a field technician in the winter time. Had to snowshoe out to the PIT tag antenna station on a tributary of the Columbia River to download data and change the battery on the receiver, but first I had to shovel out the receiver box.

During my time as an undergraduate, I also met a wonderful Swedish woman who eventually became my wife. I decided to move to Sweden to live with her and, at the same time, started my master’s degree in Fish and Wildlife Management at the Swedish University of Agricultural Sciences (SLU) in Umeå. I had an amazing experience in the master’s program and had the opportunity to work on many great projects. My master’s thesis investigated the effect of condition on smoltification and migration in anadromous Brown Trout.

After finishing my masters, I started working for the County Administrative Board of Gävleborg as a project leader in fish migration and restoration. I worked with implementing river restoration measures, fish reintroduction efforts, and conducted fish migration studies throughout Gävleborg.

Reintroduction of Atlantic Salmon and anadromous Brown Trout to upstream reaches of Dalälven. We planted egg boxes into artificial redds during the winter months to reintroduce these species to extirpated areas where hopefully they will be able to return and spawn in the future.

As a PhD student at Karlstad University, my research will focus on migration of Atlantic Salmon at three critical life stages (smolt, spawner, and post-spawner/kelt). Within the LIFE Connects project, thirteen dams are to be removed, ten fish passage solutions are to be built, and over 530 km of river habitat in seven river systems will be positively impacted. We want to evaluate the impact of these measures on Atlantic Salmon populations in these rivers and their response to restoration and re-connectivity. We will evaluate their migratory response over these three critical life stages using acoustic telemetry as our primary tool. With the use of high-resolution telemetry, we hope to gain greater insight into the timing, duration, hindrances, and mortality of these vital, large-scale migrations.

Tagging an adult Atlantic Salmon with a hydro-acoustic tag. We then release the fish and track its movements throughout the river. Collecting valuable data for the management of this important species.

In my free time you can usually catch me by or in the water. In general, I enjoy being out in nature and usually try to fill my weekends with outdoor adventures. If you have any questions feel free to contact me by email or come by my office.

Look forward to meeting you!

Next week on Tuesday 29 September kl. 13.15 RivEM professor John Piccolo will hold a seminar entitled “Nature’s contribution to people and peoples’ moral obligations to nature”. He says: “In the seminar, I will discuss the concept of “ecocentrism”, the worldview that attributes “inherent” or “intrinsic” value to nonhuman (as well as human) life. The seminar is part of a project I have been working on for some time, with colleagues from several countries, to highlight the importance of ecocentrism for biodiversity conservation and sustainability, as in this recent article in the leading biodiversity journal Conservation Biology.” You’re very welcome to join John’s Zoom room (https://kau-se.zoom.us/my/jpconbio) on Tuesday 29 September, 13:15 Stockholm time!

In the seminar next week John will focus on the new concept of “Nature’s contributions to people” (NCP) that is currently being popularized by the International Panel of Biodiversity and Ecosystem Services (IPBES). The concept of NCP is built upon a deeper understanding of the well-known Ecosystem Services paradigm. NCP attempts to capture many of the intangible values of nature that are difficult to measure, especially economically. Thus, NCP encompasses a broader range of worldviews than do previous, largely economic valuations of ecosystem services. Although the IPBES explicitly recognizes intrinsic nature value, they have done a poor job accounting for intrinsic value in their recent publications and reports. He will argue that the IPBES and biodiversity conservation in general requires a much deeper assessment of the philosophical concept of intrinsic natural value. Recognition of intrinsic value is, in fact, the foundation upon which both human rights and nature’s rights are built. Thus, intrinsic value is of primary importance in conservation of biodiversity and the broader concept of sustainability.

You can read more of their recent publications on ecocentrism at the following links:






You can even read a statement of commitment to ecocentrism, and join a list of notable signatories at the following link: https://www.ecologicalcitizen.net/statement-of-ecocentrism.php?submit=Sign+the+Ecocentrism+Statement

Karl Filipsson, Eva Bergman, Larry Greenberg, Martin Österling, Johan Watz and Ann Erlandsson recently published the paper “Temperature and predator-mediated regulation of plasma cortisol and brain gene expression in juvenile brown trout (Salmo trutta)” in the journal Frontiers in Zoology.

In this study, we tested how temperature and the presence of a cold-water adapted predatory fish (burbot, Lota lota) affected primary stress responses (i.e. cortisol and mRNA levels of stress-related genes) in juvenile brown trout (Salmo trutta). We found that trout had elevated cortisol levels in the presence of burbot, and that stress-related gene expressions varied a lot with temperature. In addition, we found that the predator-induced effects on mRNA levels were temperature dependent for some of the genes. This, together with the directly temperature-mediated effects that we observed in our study, suggest that warming winters can have major impact on primary stress responses in overwintering salmonids, for instance in encounters with predators.

In the abstract of the paper, we wrote that:

“Temperature affects many aspects of performance in poikilotherms, including how prey respond when encountering predators. Studies of anti-predator responses in fish mainly have focused on behaviour, whereas physiological responses regulated through the hypothalamic-pituitary-interrenal axis have received little attention. We examined plasma cortisol and mRNA levels of stress-related genes in juvenile brown trout (Salmo trutta) at 3 and 8 °C in the presence and absence of a piscivorous fish (burbot, Lota lota).

One of the experimental aquaria used for the study.

A redundancy analysis revealed that both water temperature and the presence of the predator explained a significant amount of the observed variation in cortisol and mRNA levels (11.4 and 2.8%, respectively). Trout had higher cortisol levels in the presence than in the absence of the predator. Analyses of individual gene expressions revealed that trout had significantly higher mRNA levels for 11 of the 16 examined genes at 3 than at 8 °C, and for one gene (retinol-binding protein 1), mRNA levels were higher in the presence than in the absence of the predator. Moreover, we found interaction effects between temperature and predator presence for two genes that code for serotonin and glucocorticoid receptors.

We extracted mRNA from the forebrain (telencephalon) of the trout. The picture shows a trout brain after dissection, where the telencephalon is the two upper lobes.

Our results suggest that piscivorous fish elicit primary stress responses in juvenile salmonids and that some of these responses may be temperature dependent. In addition, this study emphasizes the strong temperature dependence of primary stress responses in poikilotherms, with possible implications for a warming climate.”

You can read the paper for free on the journal website, as the paper is published open access through funding provided by Karlstad University.

Sebastian Rock recently started his PhD at Karlstad University. Here he writes about his previous work and what he intends to do as a PhD student at Karlstad University:

Well hi there! I’m Sebastian Rock, a new PhD student at NRRV research group at Karlstad University. Originally from the US Virgin Islands, I’ve lived across the US and later, all around Italy as well, as such, I’m hoping to bring a little extra warmth to this cold part of Sweden. Working as a part of the Life Connects project under the supervision of Martin Österling, Olle Calles, Johan Watz and Anders Nilsson (from Lund University), I’ll be working on conservation and reintroduction of highly threatened parasitic freshwater river mussels. I’ll predominantly be focused on the Freshwater Pear Mussel (Margaritifera margfaritifera) and the Thick Shelled Riven Mussel (Unio crassus) in the Skåne region in south Sweden. Where possible I hope to do scientific outreach and education to help raise both the general public interest in the less well-known aquatic fauna as well as the importance of ecologic conservation.

Sebastian with a massive 30+ kg of Laetiporus spp. (aka: Chicken Fungus, Sulfur Shelf) in Maastricht.

I started my academic life like many others as a bachelor student, myself at Maastricht University’s Maastricht Science Program in the Netherlands. Only founded in 2010, it was designed as an open end Liberal Arts and Science program, where students there are encouraged to develop their own interdisciplinary curriculum to better adapt to the modern vastly interconnected research environment. As the son of two Biologists, and as someone intensely interested in anything to do with animals, the apple didn’t fall far from the tree as I focused almost all my attention towards the biological sciences ranging from ecology to psychopharmacology. As part of the program, once a semester, students take part in a month long research project, designed with the intention of not only exposing students to a wide range of academic fields and topics, but also to provide substantial research experience to build future degrees with. Here, I got along with the zoology professor Dr John Sloggett and together organized a series of research projects on the behavioral toxicology of an invasive planarians flatworm species from North America, Girardia tigrina; these projects ultimately evolved in to my BSc thesis.

Petridish full of flatworms with BSc student Nicholas Versé in the background.

From Maastricht, I moved on to a Research Masters degree at Leiden University, also in the Netherlands, where I worked with Drs. Christian Tudorache and Marcel Schaaf at the Institute of Biology Leiden where I was able to apply my interdisciplinary background to the study of stress coping in larval zebrafish. Using Multidimensional reduction techniques, I worked on modeling coping style, the inter-individual differences in behavior (or the animal equivalent of personality) with a more straightforward and concrete measure of gestation time. Over the course of my Masters I continued to design smaller research projects for BSc students as well as working with a local international school to give short seminars and demonstrations of simple scientific projects with wide reaching implications to give them a better idea of, and hopefully inspire them to peruse an education in science.

As a researcher at KAU – NRRV I hope to apply my interdisciplinary education to the study of the effects the parasitic mussels have on their host fishes. In the case of the Pearl Mussel, salmonids, and in that of the Thick Shelled Mussel, predominantly minnows and bullheads. As much of my work will be relating to the reintroduction of these, mostly stationary, endangered parasites, they will need to be reintroduced through their more mobile host fish. As knowledge on the behavioral effects of the parasite on the fish is very limited, I hope to expand it be looking at competition behavior between infested and non-infested fish, as well as other changes in behavior, which may reduce overall fitness. After all, if we kill off all the hosts, that won’t help the parasite any more than doing nothing at all. I hope to include genomic, immunologic and abiotic factors in the conservation efforts with a little help from some multidimensional modeling to stitch it all together.

Away from the office, you can find me either outside, fishing and hunting for mushrooms, or inside building an eclectic collection of reptiles and amphibians in unique enclosures as I experiment with culinary sciences to the sound of a bizarre musical library. Feel free to stop by my office to talk about research, or any of those last three things. If you care to follow any of my sometimes semi-science related stuff you find me on Instagram @srock456.

Cheers and see you around!

Marleen Schwarze from the Leuphana University in Lüneburg, Germany, studied for a year at Karlstad University as an exchange student. Afterwards she did an internship with NRRV. Here she writes about her experiences this summer:

“Since my bachelor program Environmental and Sustainability Studies includes one year abroad, I spent the fall 2019 and spring semester 2020 at Karlstad University. During that time I got a first impression of the biology department. The interesting courses I had here awakened my interest in fresh water ecology. Also, Karlstad became a new home for me, so I was happy to be able to extend my stay and complete the study experience in Sweden with a practical internship for three months.

My main motivation was to get an insight into scientific procedures and to gain research experience. Therefore, I was glad to spend a lot of time both in the lab and in the field and also, that it was even possible to do this internship, despite the pandemic.

I worked in two research projects, which expanded my knowledge on plant and invertebrate taxonomic identification, riparian zones and research methods. One project examines the impacts of hydropeaking caused by hydropower plants on riparian zones and the benthic fauna. The fieldwork included sampling of plants, invertebrates, chlorophyll measurements, as well as abiotic such as water quality (N, P and DOC) and geological measurements. The other project looks at plant dispersal in regulated and restored rivers. We conducted vegetation surveys along a river that is regulated for hydropower purposes (Umeälven) and a river that has been restored from its channelized form (Vindelälven), and their tributaries. Further, we took soil samples to analyse soil nutrient contents (C, N and P).

Someone said that fieldwork is the best strategy for keeping social distance. After almost eleven weeks of being every day outside, I can say that it is totally true. This summer I got to know more plant species than people and I dedicated more time to macroinvertebrates than to friends. We conducted the fieldwork at different rivers in Värmland, Örebro, Dalarna, Västra Götaland and Västmanland County, as well as in Västerbotten County. Hence, this internship was not only an intense learning experience which enriched my studies, but also an opportunity to see a lot of beautiful places during summer in Sweden.

I am grateful to Lovisa Lind who coordinated my internship and all the other researchers at the KAU biology department, in particular Jacqueline Hoppenreijs, Johan Watz, Lutz Eckstein and John Piccolo. Additionally, I am glad about the great teamwork with my fieldwork collegues and fellow students Andreas Vernby, Mattias Hansson and Andreas Marklund. Further, my thanks go to the International Offices, both in Karlstad and at my home university in Lüneburg, for helping me with the administrative process and support to get Erasmus+ funding which made this internship possible for me.”