Comparison of the components of the planktonic food web in three large rivers (Rhine, Moselle and Saar)

The dynamics of phyto-, bacterio-, proto- and metazooplankton were investigated for a period of 22 months fortnightly from March 1999 until December 2000 in the rivers Moselle, Saar and Rhine. Plankton abundances reached the lowest values in the Rhine and the highest in the Saar. Protozoa and not th...

Full description

Saved in:
Bibliographic Details
Published in:River research and applications 2009-12, Vol.25 (10), p.1232-1250
Main Authors: Bergfeld, Tanja, Scherwass, Anja, Ackermann, Barbara, Arndt, Hartmut, Schöl, Andreas
Format: Article
Language:English
Subjects:
Animal and plant ecology
Animal, plant and microbial ecology
Bacteria
Biological and medical sciences
Biomass
ciliates
crustaceans
Foods
Fresh water ecosystems
Freshwater
Fundamental and applied biological sciences. Psychology
heterotrophic nanoflagellates
Invertebrates
large river
Less representative or incertae sedis groups: acanthocephala, chaetognatha, gnathostomulida, lophophoria, merostomata, mesozoa, myxozoa, nematorhyncha, pararthropoda, placozoa, priapuloidea, prochordata, pycnogonida, rotifera
Metazoa
microbial food web
Microorganisms
Nutrients
phytoplankton
Plankton
Protozoa
Rivers
rotifers
Synecology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The dynamics of phyto-, bacterio-, proto- and metazooplankton were investigated for a period of 22 months fortnightly from March 1999 until December 2000 in the rivers Moselle, Saar and Rhine. Plankton abundances reached the lowest values in the Rhine and the highest in the Saar. Protozoa and not the much more studied metazoa clearly dominate the zooplankton not only by number but also by biomass by about 90%. We show that the plankton biomass in each of the rivers is the result of the interplay of the grazing by benthic predators and of the human induced factors such as river morphology, water residence time and nutrient load. Furthermore, we compare our study with the planktonic food web of three other large European rivers. The comparison between all studies revealed a general rise of the absolute mean biomass of all heterotrophic planktonic food web components (bacteria, protozoa, metazoa) parallel to an increase of the algal biomass of the river. For the rivers Rhine, Moselle and Saar, the average biomass of all investigated plankton groups was very low compared to the values obtained in the rivers Meuse, Loire and Elbe. The relative importance of organisms of the microbial food web increased with a decrease of the algal biomass or organic carbon content, respectively, in each of the rivers. We postulate that with a sinking nutrient level in the Rhine, the microbial food web components will become even more important within the plankton than they already are. Copyright © 2008 John Wiley & Sons, Ltd.
ISSN:1535-1459
1535-1467
1535-1467
DOI:10.1002/rra.1217