Beaches and Dunes in Virginia
Eastern Shore The coastline consists of nearshore shallow water, beach, primary dune, secondary dune, and maritime forest zones. These zones work together to create a complex system that provides habitat for plants and animals and recreation for us. Photo by Shoreline Studies Program
Westmoreland A beach on the Potomac River with a wooded upland zone. Photo by Shoreline Studies Program
Gloucester A small, recreational public beach on the York River provides access to the water for the general public. Photo by Shoreline Studies Program
Northumberland A narrow beach and dune system fronting houses on the Potomac River. Shore perpendicular groins help maintain a sufficient beach width so that the dune can survive. Photo by Shoreline Studies Program
Dunes provide protection to upland structures during storms. At the site of a man-made dune on the ocean coast, Hurricane Isabel eroded a great deal of the dune, but storm surge did not impact structures on land. The dune was repaired with beach fill and replanted. Photo by Shoreline Studies Program
The man-made dune on the ocean coast three years after Hurricane Isabel. Beach fill repaired the dune, and sand fencing at the front base of the dune captures wind-blown sand from the beach. Photo by Shoreline Studies Program
Norfolk Recreational beach and dune along Norfolk’s Chesapeake Bay shoreline. Groins help maintain a sufficient beach width for the dune. Sand fencing helps stabilize the area and blocks foot traffic over the dune which can damage plants. Photo by Shoreline Studies Program
Northampton Dune plants must be very hardy. They must survive the hot, dry environment and constant burial from windblown sand. Along occupied shorelines, blowing sand can creep onto sidewalks, streets, and yards. Dune plants are susceptible to damage from foot traffic. Photo by Shoreline Studies Program
Beaches and dunes in Virginia occur in a variety of coastal settings and tide ranges. Natural and man-made beaches and dunes occur along Virginia’s southeast ocean coast, on the barrier islands off Virginia’s Eastern Shore, and in Chesapeake Bay. While the physical processes and ecosystem services are the same, Bay beaches and dunes are generally smaller and less continuous than ocean dunes. Ecosystem services are the benefits resulting from the resources and processes that are supplied by ecosystems.
Beaches and dunes are part of a system that extends from the nearshore across unvegetated or partially vegetated sand, gravel, or shell intertidal beaches, and into the dune (where they exist). Quartz sand is the foundation that comprises beaches and dunes in Virginia. The sand is eroded from banks and transported into the Bay from creeks and rivers within its watershed as well as from the ocean.
Beaches are formed by waves and currents. The life span of a beach/dune varies from a few years to several decades, or longer, depending on the sites geomorphology and local sand supply. Beaches are dynamic yet resilient features that are constantly reshaped by waves. In addition to the movement in the onshore-offshore direction, sand is transported alongshore, thus erosion at one site can provide material to an adjacent beach.
When a beach becomes wide enough, a dune can form along its landward side. Dunes form when there is an adequate supply of sand, onshore wind, and stable coastal setting.
Benefits of Beaches and Dunes
Storm Protection
Beaches and dunes provide a buffer zone which protects the upland during storms. Beaches and dunes can dampen and absorb the energy from a wave before it can impact upland structures such as houses and roads. When storms with higher water levels impact the shoreline, dunes can erode, resulting in sand being deposited on the beach or the nearshore. During periods of calm weather, the sand can migrate back up the beach and be blown back onto the dune. Sand fencing installed along the shoreline can help the process by slowing sand so that it accumulates at the base of the fence allowing plants to grow and providing stability to the area.
Habitat
Beaches and dunes provide habitats for many different types of plants and animals. Sea turtles nest along the shore, and mammals and birds forage along the beach in the dunes. Invertebrates, like crabs, insects, and molluscs, live in the nearshore, intertidal zone and back beach. Beaches and dunes are important habitats for migrating and nesting shorebirds and song birds. In Chesapeake Bay, the beaches are important habitats for the threatened northeastern beach tiger beetle.
In Virginia, common dune plants are listed in the Primary Dune and Beaches Act and determine (legally) if a site contains a jurisdictional dune. These common grasses are: American beach grass (Ammophila breviligulata); Beach heather (Hudsonia tomentosa); Amberique-bean (Strophostyles helvola); Dusty miller (Artemisia stelleriana); Saltmeadow cordgrass (Spartina patens); Seabeach sandwort (Honckenya peploides); Sea oats (Uniola paniculata); American Searocket (Cakile edentula); Seaside goldenrod (Solidago sempervirens); Japanese sedge or Asiatic sand sedge (Carex kobomugi); Virginia pine (Pinus virginiana); broomsedge (Andropogon virginicus); and Short dune grass (Panicum amarum).
Water Quality
Both beaches and dunes can positively affect water quality. Beaches are porous and allow the filtration of water and smaller-sized particles in the swash zone (the upper part of the beach between backbeach and surf zone
Plants that live along the back of the beach and in the dunes can take up nutrients that come from the land, either through rain runoff or groundwater discharge.
