Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Extreme winters impact fish negatively

14.02.2013
Ecologists from Umeå University and the Norwegian University of Science and Technology in Trondheim have studied fish communities and the living environments of fish and put together a compilation of the importance of winter conditions for fish in streams and rivers in cold regions. The findings are now being published in the journal BioScience.

It is well known that winter can be a stressful season for plants and animals in streams and rivers. It is reasonable to assume that it is the more extreme weather conditions that are the most taxing, but the ecological significance of this is poorly understood.


It is difficult to be a fish when the bottom of the river is covered with ice. Winter image from the river Orkla in Norway. Photo: Knut Alfredsen

The research team, headed by Professor Christer Nilsson at Umeå University, describes how extreme conditions – especially those associated with ice formation and ice break-up – vary over time and affect both the non-living environment and its fish. For example, waterways can fill up with ice and kill all fish that do not manage to flee to backwaters or deeper stretches of quiet water that is not filled with ice. Young fish are especially vulnerable.

The researchers also discuss how humans have impacted what happens in streams and rivers in the winter.

“Rivers that have been exploited for hydroelectric power can be especially hard for fish to live in, because the way hydropower is produced often means that the flow is radically changed again and again, which can lead to repeated ice break-ups and a great deal of bottom ice formation. When the ice cover at the surface disappears, cold air is fed downward in the water and forms ice crystals that cover the bottom, making it hard for fish to survive,” says Christer Nilsson.

The scientists draw a number of conclusions from the study. One is that more measurements are needed in order to be able to predict when extreme situations in waterways may arise and that information about both the lives of different fishes and how they are affected by extreme events should be included in such data gathering. Another is that models of how water moves and what fish populations look like should also take winter conditions into consideration.

Today most models are about the ice-free period. A third conclusion is that in order to be able to manage streams and rivers in a long-term sustainable manner, we need to pay attention to future changes in climate, for example, when we design restoration and conservation measures.

“The predictions made about what the winter climate will be like in the future say that there will be more back and forth between thaw and frost, entailing more unstable ice conditions, more rain, and flooding, and ultimately perhaps more challenges to the survival of fish in many waterways,” says Christer Nilsson.

Original publication:
The article will be published in the March issue of BioScience
Weber, C., C. Nilsson, L. Lind, K.T. Alfredsen & L.E. Polvi. 2013. Winter disturbances and riverine fish in temperate and cold regions. BioScience 63:199-210. doi:10:1525/bio.2013.63.3.8.
For more information, please contact:
Christer Nilsson, Department of Ecology and Environmental Science, Umeå University, Phone: +46 (0)90-786 60 03, E-mail: christer.nilsson@emg.umu.se

Ingrid Söderbergh | idw
Further information:
http://www.umu.se

Further reports about: BioScience fish population ice crystal ice formation

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>