Beaches and Dunes

Beaches and dunes occur in a variety of shapes, sizes, compositions, and coastal settings throughout the United States. Beaches are generally defined as stretches of sand or smaller loose particles (such as pebbles, shells, or gravel) that exist between the water and the land. Dunes are landforms that occur when there is a sufficient supply of sand or sediment and strong enough wind to promote sediment transport and, often, some type of an obstacle – vegetation being the most common – that allows the blown sand to accumulate. In many instances, healthy dune systems rely on the presence of a healthy and extensive root system from dune grasses and other vegetation to maintain their shape. Barrier islands are effectively a beach or dune system that is located offshore from the mainland.