[en] Results of estuarine and coastal studies in the Long Island Sound and the New York Bight areas are summarized briefly. ²³⁴Th and ²²⁸Th were used to determine the residence time of thorium in the water column as a function of distance from the Long Island-New Jersey coast. Results indicate that virtually all of the ²³⁴Th is taken to the sediment column on a very short time scale. Paths for the redistribution of metals in the sediment column are outlined. Studies on the sources and properties of organic carbon delivered to the estuarine systems are reviewed briefly