Reports of eutrophication and hypoxia in estuaries and near-coastal waters have increased in recent years and caused concern among scientists, managers and the general public. Patterns of hypoxia have been attributed to increased nutrient-inputs from continental watersheds as a result of increased point-source, atmospheric and non-point source inputs. For the Louisiana continental shelf in the Northern Gulf of Mexico, recent reports have indicated a significant increase in the spatial occurrence of summer hypoxia which has been ascribed to increased loading of nutrients from the Mississippi river. In addition to the observations of increased nutrient loading, there exists evidence of anthropogenic change in the Mississippi river watershed since even before the beginning of the 20th century which may affect the processing and delivery of nutrients to the Northern n Gulf of Mexico. Anthropogenic changes made to watershed include modification which have changed the flow of water in the Mississippi river significantly over the past 100 or more years. many of the change s have been a result of attempts to maintain navigations and reduce flooding along the river. These alterations, by themselves, probably have had an important influence on the way in which solutes and particles have been transferred and processed in the river.