Grazing on Bacteria and Algae by Metazoans in the Lake-river Ecosystem (River Spree, Germany)

  • Kim, Hyun-Woo (Sunchon National University, Department of Environmental Education) ;
  • Joo, Gea-Jae (Pusan National University, Department of Biology) ;
  • Walz, Norbert (Institute of Freshwater Ecology and Inland Fisheries)
  • Published : 2008.03.31


Direct effects of zooplankton grazing activities on the natural assemblage of bacterioplankton and algae were evaluated at monthly intervals, from June to October of 2000, in the middle part of the River Spree, Germany. We quantified bacterioplankton, algae, zooplankton abundance and measured carbon ingestion rates (CIRs) by zooplankton according to two zooplankton size classes: (i) micro zooplankton (MICZ), ranging in size from 30 to $150{\mu}m$ and including rotifers and nauplii, excluding protozoans and (ii) macrozooplankton (MACZ), larger than $150{\mu}m$ and including cladocerans and copepods. CIRs were measured using natural bacterial and algae communities in the zooplankton density manipulation experiments. Algae biomass (average${\pm}$SD: $377{\pm}306{\mu}gC\;L^{-1}$, n=5) was always higher than bacterial biomass ($36.7{\pm}9.9{\mu}gC\;L^{-1}$, n=5). Total zooplankton biomass varied from 19.8 to $137{\mu}gC\;L^{-1}$. Total mean biomass of zooplankton was $59.9{\pm}52.5{\mu}gC\;L^{-1}$ (average${\pm}$SD, n=5). Average MICZ biomass ($40.2{\pm}47.6{\mu}gC\;L^{-1}$ n=5) was nearly twofold higher than MACZ biomass ($19.6{\pm}20.6{\mu}gC\;L^{-1}$ n=5). Total zooplankton CIRs on algae (average${\pm}$SD: $56.6{\pm}26.4{\mu}gC\;L^{-1}\;day^{-1}$) were $\sim$fourfold higher than that on bacteria $(12.7{\pm}6.0{\mu}gC\;L^{-1}\;day^{-1})$. MICZ CIRs on bacteria $(7.0{\pm}2.8{\mu}gC\;L^{-1}\;day^{-1})$ and algae $(28.6{\pm}20.6{\mu}gC\;L^{-1}\;day^{-1})$ were slightly higher than MACZ CIRs. On average, MICZ accounted for 55.6 and 50.5% of total zooplankton grazing on bacteria and algae, respectively. Considering the MICZ and MACZ CIRs, the relative role of transferring carbon to higher trophic levels were nearly similar between both communities in the lake-river ecosystem.


  1. Kohler, J. 1994. Origin and succession of phytoplankton in a river-lake system (Spree, Germany). Hydrobiologia 289: 73-83
  2. Lair, N. 2006. A review of regulation mechanisms of metazoan plankton in riverine ecosystems: aquatic habitat versus biota. River Res. Applic. 22: 567-593
  3. Lehman, J.T. and C.D. Sandgren. 1985. Species-specific rates of growth and grazing loss among freshwater algae. Limnol. Oceanogr. 30: 34-46
  4. Porter, K.G. and Y.S. Feig. 1980. The use of DAPI for identifying and counting aquatic microflora. Limnol. Oceanogr. 25: 943-948
  5. Rocha, O. and A. Duncan. 1985. The relationship between cell carbon and cell volume in freshwater algal species used in zooplankton studies. J. Plankton Res. 7: 279-294
  6. Ruttner-Kolisko, A. 1977. Suggestions for biomass calculation of plankton rotifers. Arch. Hydrobiol. Beih. Ergebn. Limnol. 8: 71-76
  7. Servais, P., V. Grosselain, C. Joaquim-Justo, S. Becquevort, J. Thomé and J.P. Descy. 2000. Trophic relationships between planktonic microorganisms in the river Meuse (Belgium): a carbon budget. Arch. Hydrobiol. 149: 625-653
  8. Weitere, M., A. Scherwass, K.-T. Sieben and H. Arndt. 2005. Planktonic food web structure and potential carbon flow in the lower river Rhine with a focus on the role of protozoans. River Res. Applic. 21: 535-549
  9. Balushkina, E.W. and G.G. Winberg. 1979. Relationship between length and weight of planktonic crustacean. p. 58-79. In: Experimental and Field Investigations of the Biological Basis of Lake Productivity (Winberg, G.G., eds.). Zoological Institute of the Academy of Science of the USSR, Leningrad (Petersburg)
  10. Anderson, T. and D.O. Hessen. 1991. Carbon, nitrogen and phosphorous content of freshwater zooplankton. Limnol. Oceanogr. 36: 807-814
  11. Kim, H.W., S.-J. Hwang, K.H. Chang, M.-H. Jang, G.J. Joo and N. Walz. 2002. Longitudinal difference in zooplankton grazing on phyto- and bacterioplankton in the Nakdong River (Korea). Internat. Rev. Hydrobiol. 87: 281-293<281::AID-IROH281>3.0.CO;2-V
  12. Reynolds, C.S. and J.P. Descy. 1996. The production, biomass and structure of phytoplankton in large rivers. Arch. Hydrobiol. Suppl. 113: 161-187
  13. Downing, J.A. and F.H. Rigler. 1984. A manual on Methods for the Assessment of Secondary Productivity in Fresh Waters. Oxford. Blackwell Scientific Publications
  14. Ducklow, H.W. 1991. The passage of carbon through microbial food webs: results from flow network models. Mar. Microbial Foodwebs 5: 129-144
  15. Hwang, S.-J. and R.T. Heath. 1999. Zooplankton bacterivory at coastal and offshore sites of Lake Erie. J. Plankton Res. 21: 699-719
  16. Nagata, T. 1986. Carbon and nitrogen content of natural planktonic bacteria. Appl. Environ. Microbiol. 52: 28-32
  17. Lair, N., V. Jacquet and P. Reyes-Marchant. 1999. Factors related to autotrophic potamoplankton, heterotrophic protests and micrometazoan abundance, at two sites in a lowland temperature river during low water flow. Hydrobiologia 394: 13-28
  18. Weitere, M. and H. Arndt. 2002. Top-down effects on pelagic heterotrophic nanoflagellates (HNF) in a large river (River Rhine): do losses to the benthos play a role? Freshwater Biol. 47: 1437-1450
  19. Kim, H.W., S.-J. Hwang and G.J. Joo. 2000. Zooplankton grazing on bacteria and phytoplankton in a regulated large river (Nakdong River, Korea). J. Plankton Res. 22: 1559-1577
  20. Utermohl, H. 1958. Zur Vervollkommnung der quantitatuven Phytoplankton Methodik. Verh. Int. Ver. Limnol. 9: 1-38
  21. Kobayashi, T., P. Gibbs, P.I. Dixon and R.J. Shiel. 1996. Grazing by a river zooplankton community: importance of microzooplankton. Mar. Freshwater Res. 47: 1025-1036
  22. Bottrell, H.H., A. Duncan, Z.M. Gliwicz, E. Grygierek, A. Herzig, A. Hillbricht-Ilkowska, H. Kurasawa, P. Larsson and T. Weglenska. 1976. A review of some problems in zooplankton production studies. Nor. J. Zool. 24: 419-456
  23. Gaedke, U., S. Hochstadter and D. Straile. 2002. Interplay between energy limitation and nutritional deficiency: empirical data and food web models. Ecol. Monogr. 72: 251-270[0251:IBELAN]2.0.CO;2