Fish collection techniques employed will depend on stream size and whether or not the stream is wadable. Stream sample reach length will be determined by stream size and subsequent reach length needed to obtain a representative fish assemblage. Fish will be collected using both standard electrofishing and seining techniques. Regardless of capture techniques utilized, all fish will be pooled together to sort afterwards by species and age class (juvenile or adult). Depending on species abundance, the proportion of external anomalies per species will be determined by examining fish individually, or by examining each individual in a subsample and extrapolating for the total number of that species.