Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dead midges reveal living conditions of fish

05.04.2011
Microscopic remains of dead Phantom midge larvae (Chaoborus spp.) may explain a few hundred years of history of the living conditions of fish, acidification and fish death in Swedish lakes. Researchers at the University of Gothenburg, Sweden, have developed a method of using lake-bottom sediments to show when and how fish life disappeared from acidified lakes – invaluable knowledge for lake restorations in acidified regions.

“It is actually just like a journey through time. Fish hardly leave any remains of their own when they die, but if we instead study the presence of organisms that are affected by fish, we can find clear traces. By studying mandibles (mouth parts) from Chaoborus larvae in lake sediments, we can recreate the history of the lake back to the early 19th century,” says Fredrik Palm of the Department of Zoology at the University of Gothenburg.

Acidification of soil and water is one of the greatest environmental problems of modern times. A large proportion of Swedish lakes show clear signs of acidification, resulting in extensive fish death and severely reduced biodiversity.

Recent research has pointed to a clear correlation between fish death and the presence of Chaoborus larvae in lakes. Mandibles from Chaoborus larvae preserved in lake-bottom sediments can therefore be used to identify fish death and other fish changes in severely acidified lakes.

History in the rear-view mirror
The new method makes it possible to study the effects of acidification in lakes where no samples have previously been collected and where there are no historical data on fish community alterations. As it is also possible to determine the age of sediment samples, this method can additionaly reveal when different changes have occurred.
“By analysing Chaoborus mandibles that we recover in the bottom sediments we can tell how different fish communities have changed. Not only can we infer whether fish has disappeared, we can also see how different fish species have been affected. Roach, for example, are more sensitive to acidification than perch, and we have been able to show whether lakes historically have contained cyprinid fish or not. Remains of acid sensitive zooplankton can simultaneously be used to show trends of progressive acidification in lakes.

Providing a basis for restoration.

As the method reveals how the fish community in a lake has changed over the last few centuries, it can also be used to turn the clock back as a way of deciding how biological restoration of an acidified lake should proceed. The historical perspective of the method also makes it possible to analyse natural variations in lake ecosystems.

Palm and his colleagues have therefore carried out their studies in the counties of Västra Götaland and Bohuslän, Sweden, focusing in primarily on the Lake Gårdssjön area in Ucklum, which has been a centre of Swedish acidification research for many decades.

Journal: Journal of Paleolimnology 45: 101-113.
Authors: Palm, F., El-Daoushy, F., Svensson, J-E., 2011.
Titles: Fragmented subfossil Chaoborus mandibles reveal periods of cyprinid presence in lake histories.
Contact:
Fredrik Palm, Department of Zoology, University of Gothenburg
+46 31-786 3668
fredrik.palm@zool.gu.se

Helena Aaberg | idw
Further information:
http://hdl.handle.net/2077/24148

More articles from Life Sciences:

nachricht MicroRNA helps cancer evade immune system
19.09.2017 | Salk Institute

nachricht Ruby: Jacobs University scientists are collaborating in the development of a new type of chocolate
18.09.2017 | Jacobs University Bremen gGmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

New quantum phenomena in graphene superlattices

19.09.2017 | Physics and Astronomy

A simple additive to improve film quality

19.09.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>