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 Historical rainfall levels are significant in carbon emissions from soil
30.05.2017 | University of Texas at Austin

nachricht 3D printer inks from the woods
30.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New Method of Characterizing Graphene

Scientists have developed a new method of characterizing graphene’s properties without applying disruptive electrical contacts, allowing them to investigate both the resistance and quantum capacitance of graphene and other two-dimensional materials. Researchers from the Swiss Nanoscience Institute and the University of Basel’s Department of Physics reported their findings in the journal Physical Review Applied.

Graphene consists of a single layer of carbon atoms. It is transparent, harder than diamond and stronger than steel, yet flexible, and a significantly better...

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

3D printer inks from the woods

30.05.2017 | Life Sciences

How circadian clocks communicate with each other

30.05.2017 | Life Sciences

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible

30.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>