External Sources Inhibit Benthic Phosphorus Fluxes in the Lower Great Miami River, Southwest Ohio.

Human activities have increased nutrient loadings to aquatic ecosystems, especially during the past century. During low river flow in late summer and early fall, elevated concentrations of phosphorus (P) and nitrogen are present in the temperate Lower Great Miami River and contribute to its eutrophication. Although wastewater treatment plants are suspected of being major sources of P to the river, riverbed sediment has not been examined as an additional potential source of P.