Long-chain polymers from many seaweeds, microscopic algae, and bacteria have been demonstrated to reduce turbulent-flow friction in water. In the investigation all water samples tested from inland and marine sources gained friction-reduction ability when enriched with sugar, as a consequence of polysaccharide synthesis by bacteria. Biological polymers, therefore, are the probable cause of the unexplainable variations in hydrodynamic test facilities. Bacterial polysaccharides were more effective than seaweed extracts at low concentrations for friction reduction, but both were much less effective than synthetic polymers. Turbulent-flow frictional measurements were found to be sensitive for the detection, measurement, and partial characterization of long- chain polymers