1. Editorial

   • Henri Dumont

   EditorialNotes Pages: 1 - 2

2. Toxicity and isolation of the cyanobacterium Nodularia spumigena from the southern Baltic Sea in 1986

   • K. Sivonen
   • K. Kononen
   • S. I. Niemelä

   OriginalPaper Pages: 3 - 8

3. The independent and interactive effects of snail grazing and nutrient enrichment on structuring periphyton communities

   • Jane C. Marks
   • Rex L. Lowe

   OriginalPaper Pages: 9 - 17

4. Significance of a low oxygen layer for a Daphnia population in Lake Yunoko, Japan

   • Takayuki Hanazato
   • Masayuki Yasuno
   • Masaaki Hosomi

   OriginalPaper Pages: 19 - 27

5. An assessment of short-term depletion of stream macroinvertebrate benthos by drift

   • Margaret A. Wilzbach
   • Kenneth W. Cummins

   OriginalPaper Pages: 29 - 39

6. Diatom species composition along a thermal gradient in the Portneuf River, Idaho, USA

   • Deanna K. Vinson
   • Samuel R. Rushforth

   OriginalPaper Pages: 41 - 54

7. Fluctuations in the community composition of water-column protozoa in two southeastern blackwater rivers (Georgia, USA)

   • Leslie A Carlough

   OriginalPaper Pages: 55 - 62

8. The effect of long pools on the drift of macro-invertebrates in a mountain stream

   • John C. Martin
   • Allen W. Knight

   OriginalPaper Pages: 63 - 70

9. Upstream-downstream movements of aquatic invertebrates in a Rocky Mountain stream

   • Elizabeth A. Bergey
   • J. V. Ward

   OriginalPaper Pages: 71 - 82

10. A new bathymetric map based on echo-sounding and morphometrical characterization of the Lake of Banyoles (NE-Spain)

    • R. Moreno-Amich
    • E. Garcia-Berthou

    OriginalPaper Pages: 83 - 90