An estuary--a watery coastal conflux where tide meets river--plus the surrounding wetlands (intertidals, salt marshes, lagoons, bay mouths, etc. ) Thick with nutrients and organic matter, such zones are the highest producers in the ecosphere. Eliminating one removes the grasses needed by local fish, shrimps, snails, and other protein-rich organisms, deprives the are of a pollutant scrubber, and removes a key flood-control device. With strong-arm help from the Army Corps of Engineers, about half of the estuaries in the U. S. Have been destroyed by dredging and filling and other forms of “development. ” 95% are gone in California. See Wetland.