John Piccolo recommends the short film ”Lahontan Cutthroat Trout: A prehistoric legend returns”. The film briefly discusses the restoration of cutthroat trout to Pyramid Lake and the Truckee River in Nevada, USA. This strain of cutthroat trout was assumed extinct until remnants of the population were found in streams in neighboring Pilot Peaks. This started great efforts to re-introduce the socially and culturally important fish population to the lake. Watch the film here:

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According to tradition, Lea Schneider (center) last week nailed her thesis to the wall, at the entrance to Karlstad University. On the photo are also Martin Österling (supervisor) and Reine Lundin (dean).

On February 24, Lea Schneider, will defend her PhD-thesis ”Conservation ecology of the thick-shelled river mussel Unio crassus – the importance of parasite-host interactions”. In the abstract Lea Schneider writes: ”Unionoid mussels are globally threatened and their conservation requires species-specific knowledge on their ecology and parasite-host interaction. Unio crassus is one of Europe’s most threatened unionoid species and has a temporary obligate parasitic life stage (glochidia) on fish. A lack of suitable hosts is probably a major limitation for mussel recruitment, but host species composition, suitability and availability in time and space have yet to be fully explored. This thesis examines different aspects of the host fish species, including their composition, suitability and ecological importance, in relation to U. crassus, using both field and laboratory studies. The effects of mussel and host density on mussel reproductive potential were considered, as were aspects of evolutionary adaptations between mussels and fish and how climate change may affect their interaction.

The results show that U. crassus is a host generalist, parasitizing a variety of fish species. Host suitability and density, which varied among fish species and rivers, affected the level of glochidia encapsulation, hence mussel reproductive potential, more so than the density of mussels taking part in reproduction. Ecologically important hosts included both highly suitable primary hosts, and less suitable hosts that were highly abundant. Whether or not U. crassus has specific adaptations to its hosts to enhance juvenile transformation remains unclear. No distinct pattern of local adaptation was found, nor was there an effect of host fish presence on the timing of glochidia release by adult mussels. Instead, temperature played a major role, with results suggesting that changes in spring water temperature regimes can cause temporal and spatial mismatches in the mussel-host interaction. This thesis indicates that investigations of local mussel-host interactions help in identifying mechanisms important for unionoid conservation management and prioritization.”

The defense will take place on February 24 at 10:15 in room 1B309 (Sjöströmsalen) at Karlstad University. The frame of the thesis is available online here.

For the defense, Caryn Vaughn (University of Oklahoma, USA) is the opponent, and Leonard Sandin (Swedish University of Agriculture), Niklas Janz (Stockholm University, Sweden), and Annie Jonsson (University of Skövde, Sweden) constitute the grading committee (betygskommitté).

In the afternoon (from 13:30 onwards) the day before the defense (Feb 23), seminars related to the thesis will be given in Room 5F416 at Karlstad University. Here Caryn Vaughn will present on ”Consumer aggregations act as hotspots of ecosystem function and services in rivers”, Niklas Janz on “What is host range?”, and Leonard Sandin on “Evaluation of ecological restoration in Swedish streams – some results from the EKOLIV project”. 

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

Johan Watz, postdoc vid Karlstads Universitet, forskar om öringens vinterekologi. Just nu pågår fältarbete i Rottnan, Värmland. Johan berättar: ”Vinterförhållanden i rinnande vatten kan påverka hur mycket fisk som kan leva i älven och hur många smolt som produceras. I ett projekt tillsammans med Fortum och Bergvik Skog undersöker vi hur öringungar klarar vintern i sidofåror till Rottnan. Platser som har berikats med struktur, i form av träd som fällts i vattnet, jämförs med platser utan trädberikning. Ettåriga PIT-märkta öringar spåras genom isen, och med stationära loggerstationer. Öringarnas förflyttningar, överlevnad och tillväxt studeras. Projektet kommer fortgå fram till islossningen.”

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Johan Watz, mitt i Rottnan. ”Fältarbete i -20C kan vara så här roligt.”

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Lisse de Groot, Erasmuspraktikant från Nederländerna, vid en damm av bottenis.

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En loggerstation (vid den svarta plastpåsen) detekterar fiskar som simmar förbi.

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Teemu Collin och Niclas Carlsson (studenter vid Karlstads Universitet) pejlar öring.

Verkar detta intressant? Just nu söker Karlstads Universitet en doktorand i just fiskars vinterekologi: PhD position in Global climate change and winter ecology

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.

Dokumentären ”Tana älv – mellan tre länder” (”Tanaelv – den beste elva” på norska) ligger just nu uppe på SVT-play. FIlmen handlar om laxen i älven och människorna runt den. Forskare, förvaltare, husbehovsfiskare och repressentanter för turistfisket kommer till tals. Älven – och dess biflöden – är hem för en mängd lokalt anpassade laxpopulationer och fisketrycket måste minskas för att skydda hotade laxpopulationer. Detta skapar både lokala och internationella konflikter.

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Se filmen på SVT-Play eller på NRK:s hemsida.

A postdoc position in the ecology of river restoration is open for applications at Karlstad University: ”The main duty of the position is to conduct research on the effects of dam removal and the installation of fish-friendly turbines on river connectivity and ecology. Intact river connectivity is essential for many organisms in running water, and especially so for organisms that move between different habitats to complete their life cycle, such as many migratory fish species. Many rivers are modified by dams such as hydroelectric power plants. Dams disconnect river stretches and habitats, thereby reducing dispersal and migration possibilities for fish, benthos, and plants, with negative effects on individuals, populations, and communities. The post-doctoral candidate will be expected to evaluate the effects of complete dam removal and installation of fish-friendly turbines as measures to improve connectivity in rivers.”. The deadline for applying is February 28. Read the full announcement here:

Post-doctoral Research Fellow in Ecology of River Restoration: Dam Removal and fish-friendly Turbine

As advertised previously, NRRV at Karlstad University, also has two additional openings for full-time post-doctoral research fellows and one opening for a PhD-student (deadline February 10). Read full announcements for these positions here:

Post-doctoral Research Fellow in Aquatic-Terrestrial Linkages

Post-doctoral Research Fellow in Ecology of River Connectivity.

PhD position in Global climate change and winter ecology

A PhD-position in the field of global climate change, as it relates to the ecology of stream fishes in winter, is now open for applicants at Karlstad University. The position is a full time position for 4 years within the River Ecology and Management (NRRV) group at the Department of Environmental and Life Sciences. Read more about the position on kau.se.

As advertised previously, NRRV also has two openings for full-time post-doctoral research fellows. One position is in the field of stream-riparian ecology with focus on the reciprocal interactions and linkages between aquatic and terrestrial habitats. The other position is on river connectivity with focus on rehabilitation, management and development strategies. Read full post-doc position announcements here: Post-doctoral Research Fellow in Aquatic-Terrestrial Linkages and Post-doctoral Research Fellow in Ecology of River Connectivity.

John Piccolo, researcher at Karlstad University has written a short story for the Freshwater Working Group of the Society of Conservation Biology about his work in Klarälven. Read the story at the group’s facebook page or here below:

This is a story about some of the toughest field work I’ve carried out in over 20 years of research on salmon populations in either North America or Sweden, and describes the first documentation of a wild Atlantic salmon smolt run on the River Klarälven in central Sweden.

Klarälven is the longest river in Scandinavia, and is home to one of the world’s last remaining large-bodied landlocked Atlantic salmon (pictured) populations. The landlocked salmon migrate from Vänern, the largest lake in the EU, to spawn and rear in Klarälven (learn more about Klarälven here). After living for 2-4 years in the river, the salmon smolt migrate downstream to feed and grow in the lake. Although there has been anecdotal information about the smolt migration for many years, nobody had ever succeeded in trapping them to estimate production. Due to historical fishing pressure, and hydropower development, the Klarälven salmon are believed to be highly-threatened. However, salmon populations could also be recovering in Klarälven, because fishing pressures have reduced, and populations have gone from a low of less than 100 spawning adults to a record return of over 1000 in 2016. With this history in mind, we set out to better our understanding of salmon smolt populations in Klarälven and to guide more successful management and restoration.

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A River Klarälven smolt (photo: Teemu Collin).

As many aquatic scientists know, trapping fishes or even invertebrates in rivers can be difficult – they all tend to migrate during rising or falling flows when water levels in the river are high. Keeping a net in the water can be difficult or impossible under such conditions. Months of organic debris that has been deposited along the river banks is suddenly washed into the stream, and nets need to be cleaned often, sometimes hourly 24-hours round. An additional variable in the mix is that in large rivers, organic debris can be large (picture large tree branches or even entire trees!)! High water levels, rapid flows, and large debris are challenging obstacles, and if these obstacles bring our sampling gear down, it can be quite dangerous to get the gear up and running again. I did my first smolt trapping back in 1996 on the Salmon River in Idaho, USA. I remember watching a mature conifer tree some 30 meters long being sucked into an eddy like a drinking straw, and being ejected clear out of the river on its’ way downstream. The power of a flooding river is truly awe-inspiring.

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The crew working on the trap (photo: Teemu Collin).

It took us four sampling seasons, filled with trial and error, to achieve partial sampling success for our project. The first year we tried floating smolt traps like those often used for Pacific salmon. Although these can be adequate when there are large numbers of smolt migrating, we did not catch sufficient numbers of smolt to make mark-recapture estimates. During years two and three, we imported stationary traps, a Finnish design, that are anchored to the river bottom with 3-4-meter-long thick iron poles. It takes two days of hard labor for a work crew to drive these into the substrate by hand, balancing on the deck while holding the boat in position in the strong river flow (see photos). Inspired by the work to setup these Finnish traps, the title for this story comes from the classic song about mine workers – the iron bars didn’t weigh 16 tons, but just setting up the net was A LOT of work. Once the net was installed, the hard work began. Cleaning and emptying the net every day, and waiting for the spring flood to bring the salmon smolt. Although I was involved in this work, it is really our field crew that deserves most of the credit – it was a 24-hour a day, 7-day a week job, cleaning every day and staying vigilant for possible emergencies. During years two and three we came close to success – we had begun to catch larger numbers of smolt just at the time when flows became unmanageable and the net had to be removed. These years involved a lot of trial and error in operating and maintaining the net, cleaning, sewing mesh, clearing debris. The worst of it was cutting the net out during high flows, just when it seemed the smolt were beginning to run.

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The Finnish trap (photo: Teemu Collin).

Each year we’d improved our technique and catch; the second year we caught over 300 smolt, and made our first rough estimates of production. However, we had yet to document a substantial wild smolt run. We managed to scrape together enough funding for one more try, and set to work for our final attempt. With two years’ experience, we installed the net in record time and had a good cleaning and maintenance routine. The field crew was on the job every day and smolt numbers began to climb as did the prognosis for the spring flood. They managed to continue to fish the net right into the beginning of the flood, and finally, on the last five days that they could fish before the flood, they hit the jackpot! SMOLTS! The field crew caught over 1000 smolt during their last five days – 425 the day before they had to remove the net. This one-week catch exceeded the total number of smolt we’d caught the previous two years combined. Our mark-recapture estimates suggest that over 15,000 wild salmon smolt migrated that year, documenting substantial production of wild landlocked Atlantic salmon, probably the largest remaining population in the world. Our hard work and persistence paid off – national and international awareness of the Klarälven salmon has continued to grow, and they are the focus of renewed efforts to maintain and restore wild salmon populations that have been impacted by centuries of anthropogenic impacts.”

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Ett låglutande galler (s.k. beta-galler). Då vattenhastigheten mot gallret alltid är mindre än svephastigheten längs med gallret sveps eller leds fisken mot gallrets slut. Vid gallrets slut finns flyktöppningen – tex. en eller flera ingångar till en bypass.

Låglutande galler används allt mer för att leda nedströmsvandrande fiskar till flyktöppningar och säkra pasagevägar förbi vattenkraftverk.Låglutande galler har tillexempel installerats för att passera nedströmsvandrande fisk i Ätran och Mörrumsån. Olle Calles, forskare vid Karlstads Universitet, leder en samling projekt som under det kommande året ska studera för- och nackdelar med låglutande galler med olika spaltvidd. Idén är att experimentellt testa hur låglutande galler med olika spaltvidd påverkar den avledande funktionen för laxsmolt och ål. Men även hydrauliska förhållanden (fallförluster) och drivgodsproblematik kommer att studeras under de olika spaltvidder. Hypotesen, vad gäller fisken, är att låglutande galler har både en fysisk och en beteendemässig avledande funktion. Detta innebär att även fisk som fysiskt kan passera gallret väljer att inte göra det utan att de i stället visar en preferens för flyktöppningarna. Genom att testa olika spaltvidder hoppas man kunna hitta en spaltvidd som är optimal för att kombinera fiskpassage och vattenkraftsproduktion.

Ålprojektet finansieras av Krafttag Ål medan lax experimenten finansieras av Energiforsks ”Miljöprogram vattenkraft”.

Läs mer om ålexperimentet här: Betydelsen av spaltvidd på låglutande galler med avseende på ålpassage.