Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Killing only a few animals won't do any harm -- or will it?

25.07.2007
Using advanced mathematical modeling, researchers from Sweden and The Netherlands show in an article in the August issue of the American Naturalist that this statement is sometimes true.

Sometimes though, killing even a few individuals can have dramatic consequences, causing populations to fluctuate wildly. “The important question is: who gets killed" The effects of killing individuals crucially depend on the size of the victims,” says Tobias van Kooten, assistant professor at Umeå University in Sweden.

The regulation of populations is usually determined by the properties of one specific size class of individuals. In some species, this “crucial stage” consists of small individuals that can monopolize the available food, denying it to all other individuals.Alternatively, especially in fish populations, large individuals can limit the abundance of smaller individuals through cannibalism. It is when such a crucial size class is the target of mortality that unexpected things may happen.

Van Kooten and co-workers predict for example that in harvested cannibalistic fish populations, individuals may reach “giant” sizes, more than double the size of those in unharvested population. Indeed, such “giant cannibals” seem to occur frequently in heavily fished lakes. “Our results are directly applicable to conservation and management, since almost all human-induced mortality is size-selective,” van Kooten states. “Fishermen select gear to catch large fish, while deer hunters prefer the tender meat of calves.”

Unexpected effects of mortality have been reported before, but this systematic study, to be published in The American Naturalist, unravels the mechanisms behind the effects. Such “deep” understanding makes it possible to predict effects of size-dependent mortality for a wide range of species.

Patricia Morse | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>