Forces that Influence the Coast

Because beaches and intertidal zones are dynamic environments, the habitats they support are constantly changing. Exposed to energy of the sea and land, they are transformed on a daily, yearly, and geologic time scale. All coasts are subject to erosion, storms, and other natural forces as well as the impact of human activities. 

The continental United States has three marine shores the Pacific coast, the Atlantic coast, and the coast of the Gulf of Mexico. Including the shorelines of the Great Lakes, U.S. coasts total more than 95,000 miles (152,855 km). All three marine coastlines are exposed to many of the same natural forces. Waves and tides continually bathe their shores while winds and precipitation rebuild their substrates. In addition, the shores in all locations are occasionally exposed to the powerful forces of storms. 

Beaches and tidal zones along the Gulf of Mexico are protected from the full force of the ocean by the structure of the gulf. The presence of Central America blocks some of the ocean s energy, so gulf shores do not experience as much wave erosion as shores on the east and west coasts. The gulf coast is strongly influenced by the tremendous load of sediment from the Mississippi River. 

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