The objective of this investigation is to determine to what extent the quality of water from the habitats of large aquatic mammals can be improved by filtration through beds of sand and activated carbon. Spectrophotometric and potentiometric methods were used to monitor the various forms of nitrogen and phosphorus, and light scattering techniques were employed for turbidity measurements. Organic carbon concentrations in the filtered and unfiltered water were determined using a Dohrmann carbon analyzer. Results indicate a substantial improvement in the quality of the filtered water as reflected by decreased concentrations of carbon, nitrogen, phosphorus, and turbidity in the treated water. It is yet to be determined whether this improvement in water quality is sufficient to permit the re-use of the water for an extended period of time.