Shoreline Types in North Carolina
Shorelines in general can be delineated as to where the water meets the surface topography of the land. Shorelines are highly variable in the estuarine system and range from gently sloping land to steeply incised cliffs. The waterline (line of intersection on the land) is not constant and changes due to astronomical and wind tides, creating a shore zone. A major function of the shore zone is to absorb the energy of the water at the land and water interface. Due to the variability in slope, energy climate, sediment composition and other physical characteristics, a unique suite of organisms have adapted to live and utilize the resources of the various shoreline types. The estuarine shoreline is composed of a diverse array of shoreline types, ranging from organic and sediment bank shorelines to combination shorelines. Combination shorelines, which are a composite of two or more shoreline types, are representative of most of the estuarine shorelines.
Swamp Forest (Wetland Vegetation)
Swamp forests are very poorly drained forested wetlands or shrub/scrub communities that are regularly, occasionally, seasonally, or semi-permanently flooded by lunar tides, wind tides, and/or overbank flow. In the estuarine system, swamp forests occur along the margins of freshwater and brackish sounds and along the lower reaches of coastal rivers and streams. Swamp forests can occur directly on the estuarine shoreline or grade down a slope to marsh. A common example of swamp forest is tidal cypress gum swamp.
Marsh (Wetland Vegetation)
Coastal marshes are low-lying meadows of herbaceous plants that occur along the margins of estuaries and along the shorelines of coastal rivers and streams. Most marshes along the estuarine shoreline are subject to regular or irregular flooding by lunar tides and/or wind generated water level fluctuations. Common coastal marsh species include: Cord Grass, Black Needlerush, Glasswort, Salt Grass, Sea Lavender, Bulrush, Saw Grass, Cat-tail, Salt Meadow Grass, and Reed Grass.
Sediment bank shorelines are defined as any natural coastal area without wetland vegetation. They usually consist of a gently seaward sloping nearshore area and an associated steeply sloping, wave-cut/erosion scarp on the landward side of the beach. Sediment bank shorelines can also include characteristics such as sandy beaches, non wetland vegetation up to the water’s edge, or overwash areas on the barrier islands. Bluff shorelines are high sediment bank shorelines with a steep headland, escarpment, or cliff.
Modified with Engineered Structure
Modified with engineered structure shorelines are any shoreline with obviously visible erosion control shoreline structures. Property owners utilize bulkheads and riprap revetments to halt a loss of coastal property, to aid recreational activities, to keep shipping channels and ports open, for aesthetic purposes, or to simply hold the current shoreline in place.
Shorelines with SAV, Mudflats, Oysters, and/or Woody Debris
Shorelines can have SAV (Submerged Aquatic Vegetation), Mudflats, Oysters, and/or Woody Debris in the nearshore area. SAV is vegetation rooted in the substrate of a body of water (usually no deeper than 10 feet) that does not characteristically extend above the water surface and usually grows in beds. Mudflats are relatively flat, muddy regions found in inter-tidal areas that are exposed during times of low tide. An oyster reef is defined as a structure created by oysters growing on a firm substrate such as shell or rock, while subsequent generations attach to the older oysters, often forming clusters. Woody Debris is characterized by naturally occurring drowned trees, logs, and brush.
August 6, 2009