Preliminary qualitative estimates of the role of natural and developed marshland soils as a nitrogen or phosphorus source or sink were obtained by a limited ground and surface water survey of a marsh adjacent to Lake Wingra, near Madison, Wisconsin and by laboratory investigations of nitrogen and phosphorus transformations in soil samples from this marsh and from an acid bog in northern Wisconsin. Results are presented on the rates and pathways of these transformations. The results indicate that the marsh does not act as a significant nutrient sink. Thus while removal of the marsh by draining or filling might result in more N and P entering the lake, its presence does not appear to be a factor in lowering lake productivity. Nutrient input into the lake probably could be lowered by discharging storm sewers on mineral soil rather than on the marsh.