Variation in Fish and Macroinvertebrate Assemblages Among Seasonal and Perennial Headwater Streams

Stream channelization results in modifications to the natural meandering of stream channels. Channelized streams experience higher rates of drying in late summer and early fall because of efficient water movement and higher water temperatures. Approximately 70% of east-central Indiana landuse is rowcrop agriculture with widespread Stream channelization. We sampled fishes and invertebrates at 14 sites in seven headwater streams in the Buck Creek watershed. We defined streams that dry in late summer and early fall as seasonal, and those that maintain flow throughout the year as perennial streams. Our predictions were that alterations to the natural channel structure, which change the seasonal drying patterns of the streams, would also cause changes in fish and invertebrate assemblages. Detrended Correspondence Analyses (DCA) of fish and invertebrate assemblages produced significant correlations for resulting axes with habitat and water quality variables. No significant differences in fish and invertebrate assemblages were found in our comparisons of seasonal vs. perennial streams.