River Rottnan in winter

Johan Watz, Olle Calles, Niclas Carlsson, Teemu Collin, Ari Huusko, Jörgen Johnsson, Anders Nilsson, Johnny Norrgård and Daniel Nyqvist recently published the paper “Wood addition in the hatchery and river environments affects post-release performance of overwintering brown trout” in the journal Freshwater Biology.

In the abstract, the authors write:

“1. Habitat structural complexity affects the behaviour and physiology of individuals, and responses to the  environment can be immediate or influence performance later in life through delayed effects.

2. Here, we investigated how structural enrichment, both pre-release in the hatchery rearing environment and post-release in the wild, influenced winter growth and site fidelity of brown trout stocked into side channels of a regulated river.

3. Experiencing structural enrichment in the rearing environment during 3 months in autumn had no pre-release effect on growth, but a delayed positive effect after release during the subsequent winter. Moreover, trout recaptured in wood-treated sections of the side channels had grown more than trout recaptured in control sections. Wood enrichment in the side channels also increased overwinter site fidelity.

Johan Watz at the field site.

4. These results show that adding structure during a relatively short period may alter growth trajectories, and adding wood to side channels is a cost-effective method to enhance winter habitat carrying capacity for  juvenile salmonids in regulated rivers.”

Access the paper here.

Teemu Collin tracking trout at the field site.

 

Dead wood in a side channel of the river.

 

River Rottnan.

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.

Anissa Bengattat (middle), together with Rachel Prokopius (left), exchange student from Northern Kentucky University, and Elio Bottagisio (right), master student from France, doing fieldwork in the stream Rannån.

In April 2018, Anissa Bengattat from France visited Karlstad University and did an internship with NRRV. Here she writes about her weeks in Sweden.

Hej där!

I’m Anissa Bengattat, a French student in HND ‘Management and Protection of Nature’ in a town located in France, named Vic-en-Bigorre. As a practical training, I have been doing my three-weeks internship at Karlstad University with the Ecology and Conservation Biology program.           

During these weeks, I have learned vastly about different aspects of  freshwater ecology.  My main mission has been to collect, sort, identify and archive macro-invertebrates, collected in the field, in the freshwater stream Rannån. With the help of Richard Durtsche, guest-professor from the USA, and his student Rachel Prokopius, I managed to follow a project from the start to the end.

I have tested digital imaging of the identified invertebrates, and I have seen the calorimetry process, used in order to make links with the fishes‘ energetics consumption.

 I have also been in the stream aquarium laboratory to participate in some interesting experiments. First, I have learned about the whole fishes respirometry system, made up by R. Durtsche, where we studied oxygen consumption for brown trout. Then, I’ve learned about Karl Filipsson’s experiments about climate change effects on predation on brown trout. Their behaviour, linked to the temperature and the presence or not of burbot, and how to identify it scientifically by extracting trouts‘ RNA.

 Finally, I have attended master classes for these three last weeks, which consolidated my idea to do a bachelor after my HND, and then a master, if possible, abroad.

This internship wasn’t only about studies to me, it was also about meeting new people in another country with a different way of living, and a different way of teaching. It was about making concrete links in my mind between how much I still have to learn, and how to develop into an accomplished scientist.

Thanks to John Piccolo who set up my internship, thanks to the international office of Karlstad university which helped, and thanks to Elio Bottagisio, the French master student who told me about this program. And finally, thanks to all the people who taught me things during this internship,  Richard Durtsche, Rachel Prokopius, Olle Calles, and Karl Filipsson. I hope to come back.

Marcell Szabo-Meszaros, Christy Ushanth Navaratnam, Jochen Aberle, Knut Alfredsen (Norwegian University of Science and Technology), Ana T. Silva, Torbjørn Forseth (Norwegian Institute for Nature Research), Olle Calles (Karlstad University) and Hans-Petter Fjeldstad (SINTEF Energy Research) recently published the scientific paper “Experimental hydraulics on fish-friendly trash-racks: an ecological approach” in the journal Ecological Engineering. The study is part of the project SafePass, where methods for safe and efficient migration for salmonids and European eel past hydropower structures are evaluated. SafePass aims to facilitate fish migration in regulated rivers, using perspectives of both the fish and the hydropower industry. Read more about SafePass here.

In the abstract of the paper, the authors write: ”The obstruction of fish migratory routes by hydroelectric facilities is worldwide one of the major threats to freshwater fishes. During downstream migration, fish may be injured or killed on the trash-racks or in the hydropower turbines. Fish-friendly trash-racks that combine both ecological and technical requirements are a solution to mitigate fish mortality at a low operational cost. This study presents results from an experimental investigation of head-losses and the hydrodynamic performance of six angled trash-rack types with 15 mm bar spacing, varying bar-setup (vertical-streamwise, vertical-angled and horizontal bars) and bar profiles (rectangular and drop shape) under steady flow conditions. The trash-racks were positioned at 30° to the wall of the flume and combined with a bypass at their downstream end. The impact of the different trash-rack types on the upstream flow field was characterized using Image based Volumetric 3-component Velocimetry (V3V) and at the bypass-entrance using an Acoustic Doppler Velocimeter (ADV). The results show that trash-racks with vertical streamwise and horizontal oriented bars with drop-shape profiles have similar head-losses (13% difference), while trash-racks with vertical-angled bars provide 3–8 times larger head-losses compared to the remaining configurations. The velocity measurements showed that the highest flow velocities occurred for configurations with vertical-angled bars (0.67ms−1 and 0.81ms−1 on average, respectively).Turbulence related parameters (e.g. Reynolds shear stresses and Turbulent kinetic energy) were also investigated to evaluate the performance of the alternative trash-racks from both, engineering and ecological perspectives.”

Access the paper here, or e-mail any of the authors.

The Volumetric 3-component Velocimetry (V3V) system used in the study.

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.

 

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.

I en rapport, och vid ett seminarium på måndag i Arlanda, presenterar Karlstads universitet nu resultaten från ett femårigt forskningsprojekt som undersökt möjligheter till att öka överlevnaden hos nedströmsvandrande laxfisk i Klarälven. I ett pressmeddelande i anslutning till seminariet skriver universitetet tillsammans med Fortum:

Sedan 1930-talet har lekvandrande lax och öring årligen infångats vid första vandringshindret i älven och åkt lastbil förbi den utbyggda delen för att släppas av och möjliggöra naturlig lek på platser ovanför det åttonde kraftverket, Edsforsen. Parallellt sker kompensationsutsättningar av odlad laxfisk nedströms det första vandringshindret för att möjliggöra ett fiske efter lax och öring i Vänern. Den vilda laxfisken skyddas samtidigt genom fredningsbestämmelser.

Karlstad universitet och Fortum har bedrivit forskningssamarbete om lax och öring i Klarälven under många år. Den kumulativa dödligheten hos ung lax under nedströmsvandring och kraftverkspassager har visat sig vara hög. Bland de resultat som redovisas från det senaste projektet påvisades en ännu högre dödlighet för utlekt fisk, där endast enstaka märkta utlekta laxar framgångsrikt passerade alla dammar. Projektet – som riktat in sig på att ge underlag för att förbättra just överlevnaden för laxungar och utlekt lax på vägen från lek – visar också att spill vid kraftverken har stor betydelse för den utlekta laxens passagemöjligheter. Liknande resultat inhämtades, som en del av projektet, för ung lax i Winooski River i USA.

– Kraftverken utgör de facto vandringshinder för fisken, både uppströms och nedströms. I detta forskningsprojekt har vi fokuserat på att få kunskap om laxens vandringsbeteende för att kunna förbättra möjligheterna för fiskens nedströmsvandring. Något som tidigare varit eftersatt, inte bara i Klarälven utan på många platser i världen, säger projektledaren Larry Greenberg på Karlstads universitet.

Projektet föreslår att en ökad överlevnad bland nedströmsvandrande laxfisk skulle kunna åstadkommas genom att fisken leds av från Edsforsens turbinintag och samlas upp för transport förbi kraftverken och sätts ut nedströms Forshaga kraftverk. Eftersom det finns ytterst få exempel på avledare vid kraftverk av Edsforsens storlek och geografiska placering, är samtliga studerade åtgärdsalternativ att betrakta som experimentella och kommer att kräva utvärderingar och modifieringar under en försöksperiod som bör spänna över flera år. Av de sex olika åtgärdsförslag som studerats förordas två lösningar med s k. beta-avledare. Alternativet beräknas kosta ca. 130 milj kr som engångskostnad samt ca. 8,5 milj kr i årliga löpande kostnader.

– Det är viktigt att hitta rätt lösning för rätt vattendrag. Ett exempel på detta är just Klarälven – ett vattendrag med åtta vattenkraftverk från första vandringshinder upp till laxens kvarvarande lek- och uppväxtområden – där vi under senare tid sett en positiv trend för den unika populationen av Klarälvslax. Projektets resultat har nu gett oss viktig kunskap om hur laxstammen i Klarälven ytterligare kan stärkas, säger Marco Blixt som är fiskeansvarig på Fortum.

Av de cirka 8,3 miljoner kr som satsades i projektet mellan år 2012 och 2016 kommer 1,1 miljoner kr från Karlstads universitet, 2 miljoner kr från det EU-finansierade interregprojektet ”Vänerlaxens fria gång” samt ca 5,2 miljoner kr från Fortum: hälften från interna forskningsanslag och hälften från Fortums miljöfond, som finansieras genom försäljningen av Bra miljömärkt el.”

Rapporten finns tillgänglig online här: Förbättrad nedströmspassage för vild laxfisk i Klarälven

 

 

Herting

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.

Forskare inom NRRV vid Karlstads Universitet ska under de kommande tre åren undersöka ekologiska effekter av utrivningen av en kraftverksdamm, samt hur fisk påverkas av så kallade “fiskvänliga” turbiner. Forskningen kommer att ske i Mörrumsån (dammutrivning) och i Emån (fiskvänlig turbin). De involverade forskarna är (än så länge) Lutz Eckstein, Anders Nilsson, Olle Calles och Martin Österling och gruppen förväntas undesöka allt från växtsamhällen till fiskars beteende. Projektet finansieras av KK-stiftelsen och är ett samarbete mellan Karlstads Universitet, Uniper, Sveaskog och Power house. Läs mer om projektet på fiskejournalen.se eller på kau.se.

Är du en disputerad biolog som tycker att det här låter intressant? Projektet har utlyst en postdoc tjänst. Läs mer här.