Advances in the chemistry of rivers, estuaries, microcosms, and salt marshes—1983–1986

There have been dramatic advances in our knowledge of chemical processes in coastal waters during the past several years. Much of this work in the U.S. has focused on estuaries using larger seasonal data sets, advanced analytical techniques, and process oriented studies. The processes of interest include the scavenging of riverine substances in estuaries, the recycling of nutrient components, diagenetic exchange with anoxic sediments, and tidal flushing of land derived material and pollutants to the sea. As estuarine systems interact with the geo‐ and biosphere in a complex way, empirical data sets have been supplemented by experimental approaches including mixing experiments and controlled microcosms. Since most river‐estuarine systems experience tidal flushing, fringing intertidal salt marshes/mangroves appear to be important buffers for chemical storage, recycling, and exchange. Principle rivers of the world provide an important means for the transport of terrestrial constituents to the ocean. However, estuaries constitute an important transition zone which can provide a buffer for the extraction and recycling of those elements which eventually reach the sea. There have been important advances over the past several years by U.S. investigators showing how inorganic and organic constituents of rivers are involved either in direct (riverine) or indirect (estuarine) transport to coastal waters. These more recent studies provide both a quantitative basis and process orientation for delineating estuarine transport. This report will summarize progress in the United States since 1982 in studies of rivers, estuaries, microcosms and salt marshes.