Chemical Survey of the Tamar Estuary I. Properties of the Waters

An initial report is presented on some chemical properties of the waters in the Tamar Estuary. The results are compared to those obtained in the Western Channel during the same period. Considerable differences are shown in the concentrations of inorganic nutrients but the dissolved organic nitrogen concentrations are relatively similar. Dissolved iron has been estimated both before and after the breakdown of organic compounds by photocombustion. The results show the build-up of humic substances and associated iron after heavy rain. When the concentration of suspended sediment in the water is high it can control the level of dissolved phosphorus by removing it from rich water and releasing phosphorus into poor waters.