Primitive peoples found abundant food in coastal areas—the interface between land, sea, and air. Coastal areas have, in succession, been exploited for their fishery resources, developed for harbors and coastal works, used for the disposal of wastes, employed as sources of cooling water for powerplants, filled, dredged, diked, and degraded to the point that many are scarcely functional ecosystems. Marine fishing involves the extraction of high-quality animal protein— an essential component of the human diet—and of other natural sea products from the coastal zone. Priority must always be given to protecting the ocean’s capacity to function as a system according to its natural requirements by prohibiting uses that might interfere with its functioning. Management practices must be implemented to reduce the erosion of terrestrial sediments and structures; these might include, where feasible, the construction of sediment traps to reduce the transport of sediments into the ocean.