If you have ever flown over a coastal area and observed a river meeting the ocean, chances are you have had the opportunity to see a river plume. The patch of distinctly colored water demonstrates the clear continuity of the river flow as it enters the ocean. From this visual, it becomes obvious that rivers dominate the transfer of suspended material from freshwater sources, acting as a primary connector between continents, river-estuary systems, and the ocean.
Rivers also carry the signature of our land-based impacts, such as dam construction, land and fertilizer use, increased sewage loading, and mangrove destruction. The biogeochemical impact of river plumes and their role in supplying nutrients to tropical oceans remains poorly understood. The ocean is not an infinite sink for such impacts and more knowledge about how these materials affect the ocean chemically and biologically is needed, as this information can be applied towards coastal management plans and mitigation.