Burbot, Lota lota

On Tuesday 3 April 2018, Karl Filipsson, PhD student at Karlstad University, will give a talk titled “The effects of temperature and light conditions during winter on antipredator responses of juvenile brown trout against burbot”. The seminar will start at 13:15 in room 5F416 at Karlstad University. Everyone is welcome to attend the seminar.

A thick-shelled river mussel, Unio crassus

Between 2012 and 2016, researchers at Karlstad University have worked together with several county boards in southern Sweden in the EU-funded life project “Unio crassus for life” (målarmusslans återkomst). The thick-shelled river mussel (Unio crassus) is one of the most threatened bivalve species in Europe. In Sweden, the distribution of the species has decreased with 50% over the last 100 years.

In twelve streams in southern Sweden, a total of 300 km has been restored as part of the project to improve the habitat for the mussel. The project has also examined what fish species that are suitable hosts for the obligate parasitic larvae of the thick-shelled river mussel. Species like minnow (Phoxinus phoxinus), bleak (Alburnus alburnus) and bullhead (Cottus gobio) seem to be important hosts for the mussel. In addition, juvenile mussels have been reared in captivity with the aim to successfully reintroduce them into the wild.

The project has been very successful, and has now been nominated as one of the best EU life projects. The ceremony where the best project will be awarded is held in Brussels 23 May. Martin Österling, associate professor at Karlstad University, will attend the ceremony. We wish Martin and all other people that have worked on the Unio crassus for life project the best of luck, and we keep our fingers crossed that Unio crassus for life will be awarded the best EU life project.

Read more about the project at the Unio crassus for life official web page, or on the Skåne and Södermanland county board web pages.

The project has also gotten publicity in media, and you can read more about the project on svt or Smålands-tidningen.

Watch a short film about the project here.

Nedre Dalälven.

Projekt LIV – laxfisk i nedre Dalälven, som doktorand Anna Hagelin vid Karlstads universitet har varit projektledare för, uppmärksammades nyligen av svt nyheter i och med publiceringen av projektets slutrapport. Målet med projektet har varit att undersöka nedre Dalälvens potential att återfå livskraftiga och självreproducerande bestånd av havsvandrande lax och öring. Projektet är ett samarbete mellan länsstyrelserna i Gävleborg och Uppsala samt kraftverksägarna Fortum och Vattenfall, och finansierades till störst del genom Fortums och Vattenfalls miljöfond samt naturskyddsföreningens miljömärkning Bra Miljöval.

Restaurering av lekplatser för lax och öring i nedre Dalälven.

Det finns många vandringshinder för lax och öring i nedre Dalälven. Trots detta kan det finnas goda förutsättningar att få tillbaka självreproducerande bestånd av båda arterna. För att fiskens lekvandring ska fungera krävs det stora investeringar i form av alternativa vandringsvägar (så kallade omlöp) förbi vandringshinder som till exempel kraftverk. För tillfället kommer fisken till Älvkarleby, men länsstyrelsen Gävleborg vill göra det möjligt för fisken att själva vandra upp till sina lekområden.

Läs nyhetsartikeln på svt här, eller mer om LIV-projektet på länsstyrelsen Gävleborgs hemsida.

River Klarälven, Värmland, Sweden

A position as “Associate senior lecturer in biology with research focus on stream habitat modelling and environmental flows” at Karlstad University is now open for application. The position is a fixed-term full-time employment for four years.

”For the first three years the position will be approximately 80% research and 20% teaching. Teaching will include courses in the undergraduate and master programs in Biology. The main duty of the position is to conduct research on the effects of habitat degradation, restoration, and streamflow on stream fish populations with a focus on regulated rivers. The successful candidate will be expected to evaluate the effects of habitat and stream flow on fish distribution, growth and abundance employing advanced ecological modelling. The candidate will be the main researcher in the new project: “Advanced ecological modelling for prioritizing environmental flows and habitat restoration in regulated rivers”. The project is a collaboration between Karlstad University and key actors in river restoration including world-leading modeling consultants DHI Sweden AB, and hydropower companies Vattenfall AB Fortum AB, and Sydkraft AB.”

Read more and apply for the position here. Last application date is 2018-03-31.

The experimental flume ”Kungsrännan” under construction in Älvkarleby.

Hydropower dams block migration routes and disrupt longitudinal connectivity in rivers, thereby posing a threat to migratory fish species. Various fish passage solutions have been implemented to improve connectivity with varying success. For downstream migrating fish, low sloping turbine intake racks are used to guide fish to bypasses. Current knowledge, however, is based on hydropower plants with intake capacities <72 cm. There is also a trade-off between electricity generation and fish guidance (smaller bar spacing – better for fish, larger bar spacing – better for hydropower). Currently, gap widths/bar spacings of 10-20 mm are recommended but behavioral guidance effects open up the possibility of larger bar spacings.

During spring, Karlstad University in collaboration with Vattenfall and NINA, will experimentally study the behavior and passage performance of downstream migrating salmon smolts approaching a variety of low sloping intake racks. The experiments will be conducted in a new large experimental flume – Kungsrännan – at the Vattenfall hydraulic laboratory in Älvkarleby, Sweden. We will study the passage behavior and performance of smolts for alpha racks – inclined from the bottom up – and beta racks – angled from one side of the channel to the other – with different gap-widths (15-30 mm).

For this, we are looking for one interested and ambitious assistant to join us in Älvkarleby. The assistant will be salaried and is needed from mid-April to mid-June. Housing in the area can be provided. Are you interested in joining us? Contact Olle Calles for more information.

The principle behind downstream fish passage solutions using low sloping intake racks. The fish is swept and guided along a beta rack to a bypass at the rack’s downstream end.

A spawning male sockeye salmon (Oncorhynchus nerka)

During the 50th anniversary meeting of the Fisheries Society of the British Isles at the University of Exeter in July 2017, the participants held a workshop to develop a publication titled “Valuing and understanding fish populations in the Anthropocene: key questions to address”, for the special issue of the Journal of Fish Biology.

John Piccolo from Karlstad University contributed to this paper, focusing on a current research theme on conservation ethics. The paper is now published. Access the paper here, or contact any of the authors. John has also promised a coming NRRV post highlighting some recent work in this area.

In the abstract of the paper, the authors write:

“Research on the values of fish populations and fisheries has primarily focused on bio-economic aspects; a more nuanced and multidimensional perspective is mostly neglected. Although a range of social aspects is increasingly being considered in fisheries research, there is still no clear understanding as to how to include these additional values within management policies nor is there a cogent appreciation of the major knowledge gaps that should be tackled by future research.
This paper results from a workshop held during the 50th anniversary symposium of the Fisheries Society of the British Isles at the University of Exeter, UK, in July 2017. Here, we aim to highlight the current knowledge gaps on the values of fish populations and fisheries thus directing future research. To this end, we present eight questions that are deeply relevant to understanding the values of fish populations and fisheries. These can be applied to all habitats and fisheries, including freshwater, estuarine and marine.”

Job: Project assistant

Posted by Karl Filipsson | Jobs

A thick-shelled river mussel (Unio crassus).

NRRV is looking for a part-time project assistant to work with the endangered thick-shelled river mussel (Unio crassus). The project concerns rearing of juvenile mussels in the mussel lab in Veberöd, Skåne, and reintroduction of mussels in streams in southern Sweden. Read more and apply for the position here (Swedish). The last day to apply is 2 March 2018.

Although most fieldwork is carried out in warmer seasons, members of the NRRV research group also go out in winter to collect information and samples for their research. Here, Richard Durtsche, visiting professor from Northern Kentucky University, writes about a field excursion that took place last week:

Andrew Harbicht, Post-Doc at Karlstad University (front) and Richard Durtsche, visiting professor from Northern Kentucky University, (back) at the field site.

“As part of a study on the energetics in natural food sources available to Salmonid fishes (trout, salmon, grayling, etc.), we have been sampling the macroinvertebrates in streams that connect to the Klarälven (Clear River) this past fall and now this winter. These investigations will focus on an increase in the accuracy of macroinvertebrate body size measurements taken with digital imaging and an increase in the accuracy of dry mass measures using an ultramicrobalance, newly acquired by Kau Biology. Energetic (caloric) content will also be determined for the different macroinvertebrate taxa. The three target macroinvertebrates groups for this study include mayflies (Ephemeroptera), caddisflies (Trichoptera), and stoneflies (Plecoptera). These are major prey items for all life history stages of Salmonid fishes, and are often used as indicators of stream health in aquatic environmental assessment due to their sensitivity to pollutants and anthropogenic impacts. Results of this study will be useful in developing energetic models of fish foraging for management of fish population and river/stream conditions.

The team that braved the cold winter conditions and moderate snow levels on January 29th included: Richard Durtsche (NRRV visiting professor from Northern Kentucky University), Rachel Bowes (NRRV Post-Doc), Andrew Harbicht (NRRV Post-Doc), and Rachel Prokopius (exchange student from Northern Kentucky University). The stream that we were investigating was located just south of Ransäter. The water was flowing rapidly, and we initially decided to check out the stream conditions on the downhill (east) side of highway 62 to look for sampling sites. There was knee deep (or more) snow to ford before coming to forest cover where moving was easier despite many treefalls. As the streamflow was fast and the water level high, there were no safe locations to sample. So we headed west of highway 62, just off the access road. There we found good sampling habitat just downstream of a large pool that ran under a bridge on that road.

Rachel Prokopius, exchange student from Northern Kentucky University, and Richard Durtsche, measuring the stream width and flow rates.

One of the first things we did at waterside, was to collect physicochemical measures of the water conditions. These included: temperature, pH, conductivity, and dissolved oxygen. We also measured the flow volume of water by measuring the width of the stream, and then taking the depth and flow rates every 50 cm across the stream. Water temps of 1.4°C and the tingle of cold penetrating our waders told us that today was not a good day to fall in the water. After we crossed the fast-flowing stream, we found several relatively shallow areas where we could sample invertebrates. We made a series of kick seine samples from different parts of the stream shallows to dislodge and collect invertebrates from the stones and substrate. 

It was definitely a group effort to kick stones and stream bottom, brush rocks to knock off invertebrates to be carried with stream flow into the seine, and then wash the samples into a collecting bucket. While we thought we might have limited luck, we in fact did extremely well with collecting a range of macroinvertebrates and large quantities of many of those taxa. There will be a good share of macroinvertebrate sorting and measuring upon return to the laboratory.”

Rachel Prokopius, Rachel Bowes, Post-Doc at Karlstad University, and Andrew Harbicht sampling invertebrates using a kick seine.

 

The team at work in the stream.

 

Richard Durtsche at the field site.

 

Close-up photo of a stonefly (Plecoptera) larva.

 

Book: Biology and Ecology of Pike

Posted by Karl Filipsson | Book

The book Biology and Ecology of Pike, edited by Christian Skov (Technical University of Denmark) and Anders Nilsson (Karlstad and Lund Universities) was recently published by CRC Press. The two editors have also authored several chapters in the book. The book is described to “emphasize the progress of pike research during the past two decades, highlight human dimension aspects in recreational fisheries, and to address environmental circumstances on pike populations including the pike individuals.” Read more about the book here.