Seasonal variation of riffle and pool fish assemblages in a short mitigated stream reach

We sampled a series of contiguous rimes and pools throughout one year to examine spatial and temporal variation in stream fish assemblages on a short, mitigated reach of the Cottonwood River, Kansas. One of three rimes sampled was an artificial rime constructed as habitat restoration in an area previously dredged of gravel. Canonical correspondence analysis demonstrated differences between rime and pool fish assemblages, and indicated seasonal assemblage variation with no influence imparted by the artificial rime. Current speed, water depth, substrate character, total alkalinity, and season explained most assemblage variation. Fish assemblages were similar spatially, but, were seasonally variable. Rime fish assemblages exhibited more seasonal variability than did those of pools; 59% of the total number of fishes captured in rimes were seasonally variable compared to 12% in pools. Patterns of variability in this mitigated stream reach were similar to those reported for natural streams.