Stina Gustafsson presenting her thesis.

Last Friday, Stina Gustafsson successfully defended her PhD-thesis Habitat compensation in nature-like fishways – effects on benthos and fish”. Paul Giller (Cork University, Ireland) was the opponent, and Frauke Ecke (SLU, Sweden), Brendan McKie (SLU, Sweden) and Jouni Taskinen (University of Juväskylä, Finland) constituted the grading committee.

Stina Gustafssons supervisors during her PhD were Martin Österling and Olle Calles.

The thesis is available online here. Contact Stina Gustafsson for questions and additional information.

 

On Friday, 15 December, from 13:00, Stina Gustafsson will defend her PhD-thesis ”Habitat compensation in nature-like fishways – effects on benthos and fish”. Paul Giller (Cork University, Ireland) will be the opponent, and Frauke Ecke (SLU, Sweden), Brendan McKie (SLU, Sweden) and Jouni Taskinen (University of Juväskylä, Finland) constitute the grading committee. The defense will take place in 1B306 (Fryxellsalen) at Karlstad University. Everyone is welcome to attend!

In the abstract to the thesis, Stina Gustafsson writes: ”The construction of nature-like fishways has become an increasingly common measure to restore longitudinal connectivity in streams and rivers affected by hydroelectric development. These fishways also have the potential to function as habitat compensation measures when running waters have been degraded or lost. The habitat potential has however often been overlooked, and therefore the aim of this thesis was to examine the potential of nature-like fishways for habitat compensation, with special focus on the effect of added habitat heterogeneity. 

This thesis examines the effects of habitat diversity on the macroinvertebrate family composition and functional organization in a nature-like, biocanal-type fishway. The biocanal contained four habitat types; riffle, pool, braided channel and floodplain. The effects of habitat diversity and large woody debris on brown trout habitat choice was also investigated in the biocanal. In addition, and prior to introduction of the threatened freshwater pearl mussel into the biocanal, the suitability of different brown trout strains as hosts for the mussel was examined. 

The results show that the habitat heterogeneity in the biocanal contributed to an increased macroinvertebrate family diversity. The functional organization of the macroinvertebrate community suggests that it was a heterotrophic system and more functionally similar to the main river than to the small streams that it was created to resemble. Brown trout habitat choice studies showed that high densities of large woody debris increase the probability of fish remaining at the site of release. Testing of different brown trout strains as host for the freshwater pearl mussel revealed that both wild and hatchery-reared brown trout strains were suitable hosts. In summary, the results indicate that it is possible to create a fish passage with added value through its high habitat function and that nature-like fishways can be designed to reach multiple species restoration goals.”

The thesis is available online here.

On Thursday, 14 December 14:00, Brendan McKie, one of the members of the grading committee, will give a presentation titled:  ”River restoration and biodiversity and ecosystem functioning in tributaries of the Vindel River: The importance of restoration intensity and time”. The seminar will be given in room 5F416, at Karlstad University. Everyone is welcome to attend also the seminar.

Johan Watz, Anders Nilsson and Olle Calles from Karlstads Universitet, and Jonas Elghagen from Elghagen FIskevård, recently published the scientific note ”Evaluation of a novel mobile floating trap for collecting migrating juvenile eels, Anguilla anguilla, in rivers” in the journal Fisheries Management and Ecology.

In the abstract, the authors write: ”To improve the situation for the threatened European eel in regulated rivers, better methods need to be developed that more efficiently collect and transport juvenile eels past dams. In this study, a novel mobile, floating eel trap is described, and the results from an evaluation of the trap in two Swedish regulated rivers are presented. The mobile trap was designed to reduce the length of the climbing distance while maximizing the width of the entrance. The mobile trap caught more juvenile eels than a stationary eel ladder, serving as control. Furthermore, the mobility of the floating trap enables adaptive placement and thus offers managers the possibility to search for the spatial optimum for trapping efficiency.” Access the paper here, or e-mail any of the authors

The mobile floating trap next to the stationary eel ladder used as control. Photo from the Watz et al. 2017.

The mobile floating trap without cover. Juvenile eels climb the short and wide ramps (black) and slide (on the small metallic shutes) towards the left (in the photo) were they are collected. Photo: from the papers supplementary material.

The trap in the tailrace of a hydropower plant in River Lagan.

A sample of juvenile eels caught in the study, here held in a 10 L bucket.

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 denislafage.wordpress.com.

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).

Film: Många bäckar små

Posted by Daniel Nyqvist | Dam removal

Sportfiskarna presenterar tillsammans med Freewater Pictures filmen ”Många bäckar små”, om det rinnande vattnets naturvärden och dammutrivningsprojekt i Hudiksvalls och Nordanstigs kommuner. Se filmen här:

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Jessica Dolk märker i filmen öring med radiosändare. Det är en del av NRRVs studier på vandrande fisks beteende i Nianån, efter dammutrivning. Läs mer om dessa studier här. Undersökningen av fiskvandring i Nianån är en del av en större studie på ekologiska effekter av dammutrivning i området. 

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.”

Fiskvandring i Nianån

Posted by Daniel Nyqvist | Dam removal

Som en del av en större studie på ekologiska effekter av dammutrivning studerar NRRV, tillsammans med Hudiksvalls kommun, fiskvandring i Nianån, Hälsingland. I somras revs en kraftverksdamm, belägen 70 m från åns mynning, ut och vi studerar nu vandrande fisk i vattendraget. Vi har under hösten fångat och märkt både öring och flodnejonöga, och hopppas att följa upp med studier av vårvandrande fisk – såsom abborre, mört och id – under våren. Tidigare tog det stopp redan efter 70 m, men hur beter sig fisken i den nya situationen?

Öring vandrar under hösten upp i Nianån för att leka. Lekvandrande öring har fångats med hjälp av olika ryssjor i åns mynning och märkts med radiosändare. Vi har sedan kunnat följa dess rörelser i ån med hjälp av både manuell pejlning och fasta loggerstationer. Senare ska via analysera öringsens lekvandring i ån, bland annat hur den utforskar området uppströms den nyss utrivna dammen.

Flodnejonögon vandrar upp i ån på hösten, övervintrar i vattendraget och leker under den kommande våren. Vi fångar nejonögonen med så kallade nättingfällor vid åns mynning och märker dem med PIT-tags (små märken utan batteri som aktiveras när de kommer i närheten av en antenn, de fungerar enligt samma princip som många passerkort). Vi släpper sedan ut dem nedströms fällorna och genom att återfånga en del av de märkta nejonögonen kan vi få en bild av mängden nejonögon i ån. Vi har dessutom fällor uppströms den utrivna dammen, och kommer på så sätt undersöka huruvida nejonögonen utforskar dess områden. Genom att under vintern pejla nejonögonen manuellt kan vi också undersöka var i ån de övervintrar.

Förutom att studera fiskens beteende är vi också intresserade av vidare ekologiska frågor såsom hur fisksamhället, vegetationen och födoväven förändras som ett resultat av dammutrivningen.

I går visade Mitt i Naturen på SVT ett inslag om dammutrivningen i Nianån. I inslaget visas bilder från dammutrivningen och Johan Andreasson, från Hudiksvalls kommun, intevjuas om utrivningens bakgrund och målsättning. Se reportaget här.

Jessica Dolk, Karlstads universitet, och Johan Andreasson, Hudiksvalls kommun, märker en öring. I bakgrunden syns en ryssjorna som fångar den lekvandrande öringen.

Den radiomärkta öringens rörelser i ån övervakas med fasta loggerstationer.

Flodnejonögon fångas i en s.k nättingfälla.

Jessica Dolk vittjar en nättingfälla.

Ett flodnejonöga väntar på att märkas.