Dams and weirs have a stronger impact on the ecosystem of watercourses than was previously realized. Species diversity in the dammed area upstream of weirs shows a significant decline: the diversity of fish species is one-quarter lower on average, and species diversity among invertebrates is up to 50 percent lower. The interruption of a river course thus has greater effects on the biodiversity than the geological origin of the river itself. Scientists from the Technische Universitaet Muenchen have demonstrated this on the basis of a survey of five rivers in the catchment areas of the Elbe, Rhine/Main, and Danube. Their analysis records, for the first time, both abiotic factors, for example chemical composition, current, and river bed substrate, and biotic factors, such as the number, size, and diversity of all important animal and plant groups on the two sides of weirs. The TUM researchers will present their findings, which have already been published online in the Journal of Applied Ecology, at the annual conference of the German Limnological Society, which takes place from September 12 to 16, 2011.
Whether it is done for the generation of electricity, for flood protection, or collection of drinking water, the damming of a river represents a drastic intervention in its ecosystem. Weirs and dams alter the chemical and physical characteristics of the water and the riverbed. Their construction is accompanied by a clear decline in upstream species diversity, and this is exacerbated by successive damming. This phenomenon, which is known as "serial discontinuity," has now been measured for all important animal and plant groups by system biologists from the TUM for the first time; the information available up to now concerned only individual taxonomic groups or species. The scientists carried out a systematic survey of the aquatic organisms on both sides of the weirs in five rivers of different geological origins. Their survey revealed a significant
'/>"/>
| Contact: Undine Ziller ziller@zv.tum.de 49-816-171-5403 Technische Universitaet Muenchen Source:Eurekalert |
Related biology news :
1. Scientists concerned about pesticide education funding
2. Scientists utilise breath and sweat to detect trapped humans
3. USC scientists generate first detailed map of human neuroreceptor
4. USC scientists probe connection between sight and touch in the brain
5. Biomedical/health informatics scientists to present cutting-edge science, health IT
6. Scientists offer way to address age-old questions
7. USC scientists identify key protein linked to acute liver failure
8. Scientists make turfgrass safer for animals, deadly for insects
9. Scripps Research scientists pinpoint shape-shifting mechanism critical to protein signaling
10. New cellular surprise may help scientists better understand human mitochondrial diseases
11. Scripps Research scientists establish new class of anti-diabetic compound
| Copyright © 2003-2012 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |