Highly productive streams and streams containing large amounts of dissolved or particulate organic matter present benthic animals with problems in obtaining oxygen. To study this problem, samples of associations of benthic animals were taken from stations located above and below sources of organic wastes entering North Carolina streams. Stations were sampled in the spring and in the summer. These samples were homogenized, centrifuged, and examined spectrophotometrically for the presence and relative concentrations of hemoglobin. Dissolved oxygen determinations were also made. Data suggest an inverse relationship between red hemoglobin pigments found in areas with low oxygen and organic wastes, and black, brown, and green pigments concerned with protective coloration in streams with high dissolved oxygen concentrations.