Sites A, B, and C had unique characteristics that were best understood by examining their specific contexts, not by applying a regression or correlation analysis. Finding these patterns then led to subsequent studies in the same and in other places to determine if those patterns were more general. Figure 17 . Site A, Coal Creek, had fewer Ephemeroptera than expected. This site has an active mine in its headwaters, and Ephemeroptera are known to be sensitive to mine wastes.
Arrow indicates the position of the streamside sludge pond.
Taxa richnesses for all three orders decline at the sludge pond and slowly recover for sites downstream. The same graph also reveals the direction and magnitude of change along a longitudinal transect down the stream. Complex ecological situations require unusual analytical means. References Augspurger, C. 1996. Beals, E. W. 1973.