Hydrobiologia

, Volume 565, Issue 1, pp 39–58

Trophic Relationships in the Rhine Food Web during Invasion and after Establishment of the Ponto-Caspian Invader Dikerogammarus villosus

  • M. C. van Riel
  • G. van der Velde
  • S. Rajagopal
  • S. Marguillier
  • F. Dehairs
  • A. bij de Vaate
Article

DOI: 10.1007/s10750-005-1904-8

Cite this article as:
van Riel, M.C., Velde, G.v., Rajagopal, S. et al. Hydrobiologia (2006) 565: 39. doi:10.1007/s10750-005-1904-8

Abstract

The Rhine ecosystem is highly influenced by anthropogenic stresses from pollution, intensive shipping and increased connectivity with other large European rivers. Canalization of the Rhine resulted in a reduction of heterogeneity to two main biotopes: sandy streambeds and riverbanks consisting of groyne stones. Both biotopes are heavily subjected to biological invasions, affecting the rivers food web structure. The Ponto-Caspian amphipods, Chelicorophium curvispinum and Dikerogammarus villosus, have exerted the highest impact on this food web. The filterfeeding C. curvispinum dominated the Rhine food web on the stones in 1998, swamping the stone substrata with mud. However, in 2001 it decreased in numbers, most likely due to top-down regulation caused by increased parasitic and predatory pressure of other more recently invaded Ponto-Caspian species. D. villosus showed a fast population increase after its invasion and particularly influenced the macroinvertebrate community on the stones by predaceous omnivory. This species seemed to have maintained its predatory level after its population established. Effects of these mass invaders on the macroinvertebrate community of sandy streambeds in the Rhine are unclear. Here, low densities of macroinvertebrates were observed with the Asiatic clam, Corbicula fluminea, as most abundant species. Stable isotope values of food webs from the stones and sand in 2001 were similar. Aquatic macrophytes are nearly absent and the food web is fuelled by phytoplankton and particulate organic matter, originating from riparian vegetation as indicated by similar δ13C values. Omnivores, filter-, deposit-, and detritus-feeders are the primary and secondary macroinvertebrate consumers and function as keystone species in transferring energy to higher trophic levels. Invaders comprise 90% of the macroinvertebrate numbers, and can be considered ecosystem engineers determining the functional diversity and food web structure of the Rhine by either bottom-up or top-down regulation.

Keywords

macroinvertebratesinvadersecotopesfood webtrophic relationsstable isotopesRhine

Copyright information

© Springer 2006

Authors and Affiliations

  • M. C. van Riel
    • 1
    • 4
  • G. van der Velde
    • 1
    • 4
  • S. Rajagopal
    • 1
    • 4
  • S. Marguillier
    • 2
  • F. Dehairs
    • 2
  • A. bij de Vaate
    • 3
    • 4
  1. 1.Department of Animal Ecology and Ecophysiology, Section Aquatic Animal Ecology, Institute for Wetland and Water ResearchRadboud University NijmegenNijmegenThe Netherlands
  2. 2.Department of Analytical ChemistryVrije Universiteit BrusselBrusselsBelgium
  3. 3.Ministry of Transport, Public Works and Water Management, Institute for Inland Water Management and Waste Water TreatmentLelystadThe Netherlands
  4. 4.Member of Netherlands Centre for River StudiesDelftThe Netherlands