French Broad River Macroinvertebrates 



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Fig 



MONTH/YEAR 



4. Total taxa richness, French Broad River, February 1978-June 1979. 



both season and discharge rate. However, total taxa richness at other 

 stations showed considerable seasonal fluctuation. This fluctuation is 

 not random; two distinct patterns may be observed. First, taxa richness 

 values at these other stations were roughly parallel, suggesting that the 

 same factor (above station 2) controlled the benthos at all stations. 

 Second, reductions in taxa richness occurred primarily during the spring 

 and/ or summer period. Taxa richness values at all stations tended to 

 converge in winter and fall. 



Abundance: Stream Stations. — Although five stream stations were 

 sampled, data are presented only for the "control" stations of Morgan 

 Mill (MM-1) and Cherryfield (CF-1) creeks (Fig. 5). There appear to be 

 two peaks (spring and fall) per year. This is an expected pattern for 

 temperate streams (Hynes 1972). Organism abundance was greater at 

 station MM-1 than that observed at station CF-1, but seasonal trends 

 were parallel for these two areas. 



Taxa Richness: Stream Stations. — Taxa richness values suggest lit- 

 tle seasonal variation, although values tended to be slightly higher in 

 winter and early spring (Fig. 6). A marked divergence between stations 

 MM-1 and CF-1 was observed only during the period October 1978 

 through January 1979. This is the same period when the fish kill 

 occurred above station 2 on the French Broad. 



