Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Midge bones in lake sediments reveal fish history

12.05.2009
The mouth parts of the phantom midge are microscopic. But in the hands of scientists from the Department of Zoology at the University of Gothenburg these midge bones become a time machine that can document 200 years of acidification and fish elimination in Swedish lakes.

Acidification of land and water is one of the greatest environmental problems of modern time. Many European lakes still show obvious signs of acidification, and have lead to extensive fish elimination and severely reduced biological diversity.

arlier research has shown a clear connection between fish elimination and larvae of the phantom midge, where a reduction in the fish population can lead to an explosion of phantom midge larvae in acidified lakes.

This invasion of midges forms the basis of a unique research project at the University of Gothenburg. Researchers can now reconstruct the development of fish population in acidified lakes and learn how the population has changed in past centuries by investigating mouth parts of phantom midges that have been preserved in lake sediments.

"What we do can, in fact, be viewed as a journey through time, in which we reconstruct the history of a lake from the early 19th century onwards. We analyse the occurrence of the phantom midge mouth parts and determine which species are present in the sediments. This allow us to determine whether the number of fish has increased or decreased through history, whether fish have been eliminated completely and disappeared from the lake, and we can also give a rough description of when different fish species have been eliminated during periods of severe acidification", says Fredrik Palm, doctoral student and researcher in the Department of Zoology at the University of Gothenburg.

This method of investigation makes it possible to study the effects of acidification in lakes in which samples have not previously been taken, and where historical information about the fish population is not available.

"Such studies, in turn, make it possible to decide how the biological restoration of an acid lake should be carried out, since it reveals the structure of a fish population that should be the restoration target, in order for the lake to be considered fully restored", says Fredrik Palm.

The historical perspective of the method also makes it possible to survey natural variations in lake ecosystems. In this way, scientists can estimate human impact on lake ecosystems and relate this to climate change, eutrophication and acidification. Fredrik Palm is carrying out his studies in Västra Götaland and Bohuslän, with a special focus on the Gårdsjön area in Ucklum. This region has been an important centre of Swedish acidification research for decades.

Contact:
Fredrik Palm, Department of Zoology, University of Gothenburg
Tel: 46 (0)31 786 3668
Mobile: 46 (0)703 756668
fredrik.palm@zool.gu.se
BY: Krister Svahn
46 (0)31 786 49 12
krister.svahn@scinece.gu.se

Helena Aaberg | idw
Further information:
http://www.gu.se/
http://www.science.gu.se/english/News/News_detail?contentId=878399

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>