Figure 1.

A principal component analysis (PCA) of environmental variables (red arrows) measured at stream sites (black points). Abbreviations: Depth: water depth, Width: stream width, Shrub.Density: separation score of shrubs along stream shore, DissOxygen: average concentration of dissolved oxygen, Surface.Clutter: average score of water surface coverage by vegetation clutter, %Canopy.cover: percentage of tree canopy cover, Conductivity: average water conductivity, SO4: average concentration of dissolved sulfate, pH: average pH of stream water, #Detects: average number of pesticides detected, Water.Temp: average water temperature, Sum.Nitrogen: average concentration of dissolved nitrate, nitrite and ammonium combined, SumTU: average sum of pesticide toxicity for freshwater invertebrates, PO4: average concentration of dissolved phosphate, Wastewater: total number of wastewater indicators detected.